Every sentencehas a source.

Alomary SA, Baker NJ, Ugwueke G, et al. · JAMA Dermatology · doi:10.1001/jamadermatol.2026.3579

Expert dermatologists agreed that changing hair removal habits is first-line treatment and endorsed laser hair removal; no consensus was reached on multi-blade razors.

Ingrown hairs (pseudofolliculitis barbae)

Gallo G, Sciamarrelli N, Ribero S, Mastorino L, Quaglino P, Rosset F · International Journal of Dermatology · doi:10.1111/ijd.70282

Proposed a practical scoring tool for assessing beard involvement in alopecia areata in a standardized way.

Alopecia areata

NHS · NHS

The NHS explains that nail fungus causes discoloration, thickening and crumbling of the nail, that treatment takes a long time, and why treating athlete's foot early matters.

Athlete's foot

Huang Y, Chen S, Liu X, et al. · Journal of Cosmetic Dermatology · doi:10.1111/jocd.16620

In 215 male rosacea patients, showed that the most common sign was persistent redness, that nose involvement was prominent and that the condition was more severe after age 45.

Rosacea

King B, Mostaghimi A, Shimomura Y, Piraccini BM, Blume-Peytavi U, Sontag A, Dutronc Y, Denning K, Kolodsick J, Lu X, Srivastava A, Sinclair R · American Journal of Clinical Dermatology · doi:10.1007/s40257-025-00932-0

Evaluated safety data for a JAK inhibitor used for up to four years in severe alopecia areata across two large phase 3 trials.

Alopecia areata

Reynolds RV, Yeung H, Cheng CE, et al. · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2023.12.017

The American Academy of Dermatology's current guideline gives strong recommendations for topical retinoids, benzoyl peroxide and, in severe acne, oral vitamin A–derived treatment.

AcneBack and chest acne

Sompochpruetikul K, Khongcharoensombat T, Chongpison Y, et al. · Journal of Dermatology · doi:10.1111/1346-8138.17109

In men with mild to moderate acne, taking whey protein daily for six months did not significantly worsen acne compared with the control group.

Acne

Muhaidat J, Qablan A, Gharaibeh F, et al. · Dermatology Research and Practice · doi:10.1155/2024/2158229

Among 201 young male gym-goers, whey supplement use was more common in those with acne than in those without.

Acne

Kamrani P, Boen M, Fabi SG · Journal of Drugs in Dermatology · doi:10.36849/JDD.8199

Reviewed efficacy and safety data on the CO2 and Er:YAG lasers used to treat rhinophyma.

Rosacea

Polaskey MT, Chang CH, Daftary K, et al. · JAMA Dermatology · doi:10.1001/jamadermatol.2024.1987

Combining 121 studies, calculated the global prevalence of seborrheic dermatitis at 4.38%, and 5.64% in adults.

Seborrheic dermatitis (face, eyebrows and beard)

Boodoo C, Duta D, Swift N, et al. · Skin Research and Technology · doi:10.1111/srt.13598

In 59 men, showed that a single-blade safety razor caused significantly less post-shave redness than a three-blade cartridge razor.

Shaving irritation (razor burn)

American Academy of Dermatology · AAD Public Education

Recommends wetting your hair before shaving, using a shaving cream suited to sensitive skin, shaving with the grain and replacing your blade every 5–7 shaves to reduce irritation.

Shaving irritation (razor burn)Short beard / stubbleWet shave or electric shaver? Which one is easier on your skin?Razor hygiene: small habits, comfortable skin

Kuruvella T, Saleh HM, Pandey S · StatPearls

Summarized how fungal infection of the beard area spreads, its symptoms and the fact that it usually requires oral antifungal treatment.

Beard folliculitis and beard itch

American Academy of Dermatology · American Academy of Dermatology Association

Advised leaving dandruff shampoo on the scalp for a few minutes and noted that shampoos with different active ingredients can be alternated.

DandruffDry scalp

Gómez-Arias PJ, Gay-Mimbrera J, Rivera-Ruiz I, Aguilar-Luque M, Juan-Cencerrado M, Mochón-Jiménez C, Gómez-García F, Sánchez-González S, Ortega-Hernández A, Gómez-Garre D, Parra-Peralbo E, Isla-Tejera B, Ruano J · Dermatology and Therapy · doi:10.1007/s13555-024-01281-2

Reported that scalp microbiota imbalance is linked to disease severity and inflammatory markers in the blood, though the cause-and-effect relationship isn't yet clear.

Alopecia areata

American Academy of Dermatology · American Academy of Dermatology Association

Explained that alopecia areata isn't contagious, can affect the beard, eyebrows and eyelashes as well as the scalp, and that hair often grows back.

Alopecia areata

Kang DH, Kwon SH, Sim WY, Lew BL · Annals of Dermatology · doi:10.5021/ad.24.043

In 140 people with weight-loss-related telogen effluvium, the average rate of weight loss was 3.54 kg per month, and this rate was markedly higher in men than in women.

Telogen effluvium

NHS · NHS

The NHS recommends drying thoroughly between the toes, using a separate towel for your feet, wearing clean cotton socks every day and not wearing the same shoes for more than 2-3 days in a row.

Athlete's foot

American Academy of Dermatology · AAD Public Education

Offers basic care advice such as choosing a shampoo for your hair type, focusing shampoo on the scalp, using conditioner after every wash and protecting hair from the sun.

Curly hairThick and dense hair

Misery L, Halioua B, Skayem C, Baissac C, et al. · Journal of the European Academy of Dermatology and Venereology 38(2):e191-e192 · doi:10.1111/jdv.19527

A study with participants from many countries reported that the perception of a sensitive scalp is common worldwide.

Sensitive scalp

Oizumi R, Sugimoto Y, Aibara H · JMIR Dermatology · doi:10.2196/51962

Reviewed how regular exercise can increase skin blood flow and hydration and ease age-related changes, while swimming in chlorinated pools can strain the barrier.

Athletic men

American Academy of Dermatology · AAD

Recommended applying enough of a broad-spectrum product of at least SPF 30 before going outside and reapplying it at regular intervals.

Sunscreen is a must for men too: thick skin is no shield

NHS · NHS

Stated that hepatitis C can spread through sharing personal items that may have blood on them, such as razors and toothbrushes, and that these items should not be shared.

Razor hygiene: small habits, comfortable skin

Furth G, Marroquin NA, Kirk J, et al. · JMIR Dermatology · doi:10.2196/43020

Highlighted the link between anabolic-androgenic steroid use in bodybuilding and acne, including severe, sudden-onset forms.

Acne

Costello L, Goncalves K, Maltman V, et al. · Frontiers in Medicine · doi:10.3389/fmed.2023.1236790

Developed a laboratory method combining tape stripping and human skin equivalent models to study the effect of shaving on the skin's protective surface layer.

Shaving irritation (razor burn)

Dalia Y, Khatib J, Odens H, Patel T · Clinical and Experimental Dermatology · doi:10.1093/ced/llad075

Reviewed the available treatment options for ingrown hairs, including shaving changes, topical treatments and lasers, along with their evidence.

Ingrown hairs (pseudofolliculitis barbae)

DermNet · DermNet NZ

Explains the symptoms of ingrown hairs, the transfollicular and extrafollicular penetration mechanisms and shaving tips in patient-friendly language.

Ingrown hairs (pseudofolliculitis barbae)Curly hair

Winters RD, Mitchell M · StatPearls

Summarized the bacterial, fungal and yeast types of folliculitis, their risk factors and treatment approaches.

Beard folliculitis and beard itch

DermNet · DermNet NZ

Explains the causes of folliculitis, its superficial and deep types and care tips in patient-friendly language.

Beard folliculitis and beard itchShort beard / stubblePatchy and thin beardRazor hygiene: small habits, comfortable skin

Chen Y, Hysi P, Maj C, Heilmann-Heimbach S, Spector TD, Liu F, Kayser M · European Journal of Human Genetics · doi:10.1038/s41431-022-01201-y

Models built on genetic data from more than a hundred thousand men showed that male pattern hair loss can be genetically predicted to some extent.

Male pattern hair loss

NHS · NHS (National Health Service)

Explained that male pattern hair loss runs in families, usually starts at the temples and crown, and when to see a doctor.

Male pattern hair lossFine and thinning hairPatchy and thin beard

NHS · NHS (National Health Service)

Explained that dandruff isn't contagious, can be controlled with dandruff shampoos, and that you should see a doctor if it doesn't improve.

DandruffOily scalpDandruff or dry scalp? What are the flakes on your shoulders telling you?

DermNet · DermNet NZ

Explained the triggers of telogen effluvium, the shedding that typically starts 2-3 months after the event and that hair usually grows back on its own.

Telogen effluvium

DermNet · DermNet NZ

Explained that post-inflammatory hyperpigmentation can develop after anything that inflames the skin and that sun protection is essential while it fades.

Dark spots and hyperpigmentation

DermNet · DermNet NZ

Explained the pigment, vascular and shadow-related types of dark circles and the approaches that can be used for each.

Dark circles and under-eye bags

Leung AK, Barankin B, Lam JM, Leong KF, Hon KL · Drugs Context · doi:10.7573/dic.2023-5-1

Athlete's foot was reported to be more common in men, to peak between ages 16 and 45, and topical antifungals were described as the foundation of treatment for superficial cases.

Athlete's foot

Kaiser M, Abdin R, Gaumond SI, Issa NT, et al. · Clinical, Cosmetic and Investigational Dermatology 16:1387-1406 · doi:10.2147/CCID.S385861

Reviews the current options used under a physician's assessment for male pattern hair loss, the importance of starting early, and the needs that remain unmet.

Fine and thinning hair

DermNet · DermNet NZ

Explains that seborrheic dermatitis shows up as flaking and redness on the scalp, face and beard area, is common in adult men and tends to flare periodically.

Oily scalpLong and full beard

Souza EN, Anzai A, Fechine COC, Valente NYS, Romiti R · Skin Appendage Disorders 9(6):407-415 · doi:10.1159/000533795

Reviews how a sensitive scalp shows up with subjective symptoms such as itching, burning, stinging and hair pain, has many internal and external triggers, and is approached first through scalp care.

Sensitive scalp

Dall'Oglio F, Nasca MR, Gerbino C, et al. · Clinical, Cosmetic and Investigational Dermatology · doi:10.2147/CCID.S284671

Gave an up-to-date summary of the diagnosis of seborrheic dermatitis and treatment options including antifungals, anti-inflammatories and maintenance therapy.

Seborrheic dermatitis (face, eyebrows and beard)Long and full beard

Gupta AK, Venkataraman M, Talukder M, Bamimore MA · JAMA Dermatology · doi:10.1001/jamadermatol.2021.5743

A network meta-analysis of studies in male patients showed that different doses and forms of topical solutions and DHT-reducing drugs increased hair count to different degrees.

Male pattern hair loss

Uhrlaß S, Verma SB, Gräser Y, Rezaei-Matehkolaei A, Hatami M, et al. · J Fungi (Basel) · doi:10.3390/jof8070757

A multidimensional review showing that a new dermatophyte causing widespread, treatment-resistant jock itch and body ringworm has spread from India to the rest of the world.

Jock itch

Thyssen JP, Schuttelaar MLA, Alfonso JH, Andersen KE, Angelova-Fischer I, et al. · Contact Dermatitis · doi:10.1111/cod.14035

The European guideline recommended reducing exposure, protective measures, moisturizing, patch testing and stepwise treatment for hand eczema.

Hand eczema

Larson PJ, Zhou W, Santiago A, Driscoll S, et al. · Nature Aging · doi:10.1038/s43587-022-00287-9

Showed that microbiome changes in later life are linked more to frailty than to calendar age, and that skin microbiome balance is especially important during this period.

60 and over

Daou H, Paradiso M, Hennessy K, Seminario-Vidal L · Dermatology and Therapy · doi:10.1007/s13555-020-00460-1

Systematically reviewed how changes in the skin and gut microbiome may play a role in the development of rosacea.

Rosacea

Tao R, Li R, Wang R · Experimental Dermatology · doi:10.1111/exd.14450

Showed that both the ratio between yeast species and the bacterial balance change in seborrheic dermatitis and dandruff, and that these changes are linked to barrier damage and itching.

Seborrheic dermatitis (face, eyebrows and beard)

Sukakul T, Bunyaratavej S, Chaweekulrat P, et al. · Journal of Dermatology · doi:10.1111/1346-8138.16034

In 340 men, found that the most common shaving problems were irritation and dryness, razor burn, nicks and ingrown hairs, and that these were linked to skin type and shaving technique.

Shaving irritation (razor burn)Short beard / stubblePatchy and thin beard

Tshudy MT, Cho S · Military Medicine · doi:10.1093/milmed/usaa243

Showed that ingrown hairs are a common problem among military personnel required to shave, with shaving techniques and creams working best in mild to moderate cases and lasers in severe cases.

Ingrown hairs (pseudofolliculitis barbae)

Moreno-Arrones OM, Lobato-Berezo A, Gomez-Zubiaur A, Arias-Santiago S, Saceda-Corralo D, Bernardez-Guerra C, Grimalt R, Fernandez-Crehuet P, Ferrando J, Gil R, Hermosa-Gelbard A, Rodrigues-Barata R, Fernandez-Nieto D, Merlos-Navarro S, Vañó-Galván S · Journal of the European Academy of Dermatology and Venereology · doi:10.1111/jdv.17045

A multicenter study in Spain described telogen effluvium starting a few months after infection in patients who had COVID-19.

Telogen effluvium

John SM, Garbe C, French LE, Takala J, Yared W, Cardone A, Gehring R, Spahn A, Stratigos A · Journal of the European Academy of Dermatology and Venereology · doi:10.1111/jdv.17011

Stressed that outdoor workers receive at least 2-3 times more UV than indoor workers and that their daily exposure often exceeds recommended limits.

Sun damage and premature aging

Roberts CA, Goldstein EK, Goldstein BG, Jarman KL, Paci K, Goldstein AO · Journal of Drugs in Dermatology · doi:10.36849/JDD.5470

A survey of 705 men found that most participants didn't use sunscreen every day, and that the main motivations of those who did were lowering skin cancer risk and looking younger.

Sun damage and premature aging

Elbuluk N, Grimes P, Chien A, Hamzavi I, Alexis A, Taylor S, Gonzalez N, Weiss J, Desai SR, Kang S · American Journal of Clinical Dermatology · doi:10.1007/s40257-021-00633-4

Highlighted that acne-related marks appear more often as pigment in darker skin and as redness in lighter skin, and are often more bothersome than active acne.

Dark spots and hyperpigmentation

Laughter MR, Maymone MBC, Mashayekhi S, Arents BWM, Karimkhani C, et al. · Br J Dermatol · doi:10.1111/bjd.19580

According to Global Burden of Disease data, atopic dermatitis was shown to be one of the skin diseases that places the greatest burden on quality of life.

Atopic dermatitis

Quaade AS, Simonsen AB, Halling AS, Thyssen JP, Johansen JD · Contact Dermatitis · doi:10.1111/cod.13804

In the general population, the lifetime prevalence of hand eczema was 14.5%, the one-year prevalence 9.1% and the point prevalence 4.0%.

Hand eczema

Griffiths CEM, Armstrong AW, Gudjonsson JE, Barker JNWN · Lancet · doi:10.1016/S0140-6736(20)32549-6

A comprehensive review summarizing the immune-based mechanisms of psoriasis, its associated conditions and current treatment options, including biologic drugs.

Psoriasis

Punyani S, Tosti A, Hordinsky M, Yeomans D, et al. · Skin Appendage Disorders 7(3):183-193 · doi:10.1159/000512786

Questioned the belief that frequent washing damages hair and reported that increasing wash frequency according to scalp condition can improve scalp comfort and appearance.

Straight hairFine and thinning hairThick and dense hairOily scalpHair loss myths: hats, frequent washing and more

Suzuki K, Inoue M, Cho O, Mizutani R, et al. · Microorganisms 9(10):2132 · doi:10.3390/microorganisms9102132

Showed that men with male pattern hair loss have a different sebum composition and a disrupted bacteria-yeast balance on the scalp, suggesting that sebum and the microbiome may play a role in this process.

Fine and thinning hairOily scalp

Paciência I, Rodolfo A, Leão L, Silva D, Cavaleiro Rufo J, et al. · International Journal of Environmental Research and Public Health · doi:10.3390/ijerph18020653

Showed that in elite swimmers, water loss from the skin rose more noticeably after a 2-hour pool session than in soccer players, and that the chlorinated pool environment can affect barrier function.

Athletic men

Heng AHS, Chew FT · Scientific Reports · doi:10.1038/s41598-020-62715-3

Systematically reviewed studies on acne epidemiology, summarizing its prevalence and possible risk factors such as genetics and diet.

Acne

Yu Y, Dunaway S, Champer J, et al. · British Journal of Dermatology · doi:10.1111/bjd.18088

Reviewed laboratory and clinical findings on oral and topical probiotics in skin diseases including acne, noting that the results are promising but limited.

Acne

Knackstedt R, Knackstedt T, Gatherwright J · Experimental Dermatology · doi:10.1111/exd.14032

Reported that probiotics applied to the skin showed promising results in conditions such as acne and eczema, but that larger, well-designed studies are needed.

Oily skin, blackheads and large poresSeborrheic dermatitis (face, eyebrows and beard)Atopic dermatitisBack and chest acneOily skin30s

Schaller M, Almeida LMC, Bewley A, et al. · British Journal of Dermatology · doi:10.1111/bjd.18420

An international expert panel recommended planning rosacea diagnosis and treatment separately for each sign.

Rosacea

Thiboutot D, Anderson R, Cook-Bolden F, et al. · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2020.01.077

Summarized topical, oral and laser treatment options for rosacea by sign, offering a guide to personalized treatment.

Rosacea

Lee HH, Gwillim E, Patel KR, Hua T, Rastogi S, Ibler E, Silverberg JI · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2019.08.032

A meta-analysis of 94 studies found that alopecia areata affects about 2% of the world's population and that its frequency has increased over time.

Alopecia areata

Asghar F, Shamim N, Farooque U, Sheikh H, Aqeel R · Cureus · doi:10.7759/cureus.8320

Summarized that telogen effluvium can be triggered by medications, trauma, and emotional and physiological stress, and that finding and removing the cause is the core of treatment.

Telogen effluvium

Langan SM, Irvine AD, Weidinger S · Lancet · doi:10.1016/S0140-6736(20)31286-1

A comprehensive review summarizing how atopic dermatitis relates to barrier dysfunction, the immune response and the microbiome, along with current treatment options.

Atopic dermatitis

Natsch A, Emter R · Philos Trans R Soc Lond B Biol Sci · doi:10.1098/rstb.2019.0269

A review summarizing at the molecular level that underarm odor forms when odorless precursor substances secreted by the body are broken down by enzymes of armpit bacteria.

Excessive sweating and body odor

Agner T, Elsner P · J Eur Acad Dermatol Venereol · doi:10.1111/jdv.16061

A review evaluating the prevalence of hand eczema, its tendency to become chronic, occupational risk factors and prevention strategies.

Hand eczema

Armstrong AW, Read C · JAMA · doi:10.1001/jama.2020.4006

A review covering the clinical types of psoriasis, topical, light, systemic and biologic treatments, and monitoring of associated conditions.

Psoriasis

Parisi R, Iskandar IYK, Kontopantelis E, Augustin M, Griffiths CEM, et al. · BMJ · doi:10.1136/bmj.m1590

The prevalence of psoriasis was estimated to range from 0.14% in East Asia to 1.99% in Australasia, at 1.92% in Western Europe and 1.83% in Central Europe.

Psoriasis

Ogunbiyi A · Clinical, Cosmetic and Investigational Dermatology · doi:10.2147/CCID.S149250

Summarized that ingrown hairs are linked to curved hair follicles and shaving, that the risk is six times higher in people carrying a specific keratin gene change, and that stopping shaving usually resolves the condition.

Ingrown hairs (pseudofolliculitis barbae)Dark spots and hyperpigmentationSensitive and shave-prone skinCurly hairShort beard / stubblePatchy and thin beard20sWet shave or electric shaver? Which one is easier on your skin?Skin care under your beard: the skin beneath matters as much as the beard

Nussbaum D, Friedman A · Journal of Drugs in Dermatology

Stated that ingrown hairs can occur in anyone who shaves, are more common in people with curly hair, and that the most effective approach combines changes in shaving habits with topical treatments.

Ingrown hairs (pseudofolliculitis barbae)

Ho BS, Ho EXP, Chu CW, Ramasamy S, Bigliardi-Qi M, de Sessions PF, Bigliardi PL · PLoS One · doi:10.1371/journal.pone.0216330

Showed that an acne-associated bacterium increased in miniaturized hair follicles on the crown and that this may be linked to the immune response in the follicle.

Male pattern hair loss

Simakou T, Butcher JP, Reid S, Henriquez FL · Journal of Autoimmunity · doi:10.1016/j.jaut.2018.12.001

Reviewed alopecia areata as a multifactorial autoimmune condition in which genetics, immunity, environmental factors and the microbiome all play a role.

Alopecia areata

Pinto D, Sorbellini E, Marzani B, Rucco M, Giuliani G, Rinaldi F · PLoS One · doi:10.1371/journal.pone.0215206

Showed for the first time that the bacterial community on scalps with alopecia areata differs from that on healthy scalps.

Alopecia areata

Rebora A · Clinical, Cosmetic and Investigational Dermatology · doi:10.2147/CCID.S200471

Discussed the classification of telogen effluvium, how to tell it apart from male pattern hair loss and the importance of care and empathy in approaching patients.

Telogen effluvium

Almohanna HM, Ahmed AA, Tsatalis JP, Tosti A · Dermatology and Therapy · doi:10.1007/s13555-018-0278-6

Highlighted that deficiencies of nutrients such as iron, vitamin D and zinc may be linked to hair loss, and that evidence for supplementing without a deficiency is limited.

Telogen effluvium

Burns EM, Ahmed H, Isedeh PN, Kohli I, Van Der Pol W, Shaheen A, Muzaffar AF, Al-Sadek C, Foy TM, Abdelgawwad MS, Huda S, Lim HW, Hamzavi I, Bae S, Morrow CD, Elmets CA, Yusuf N · Experimental Dermatology · doi:10.1111/exd.13854

Showed in male volunteers that UVA and UVB rays markedly changed the composition of the skin microbiome, both qualitatively and quantitatively.

Sun damage and premature aging

Goodman GD, Kaufman J, Day D, Weiss R, Kawata AK, Garcia JK, Santangelo S, Gallagher CJ · The Journal of Clinical and Aesthetic Dermatology

Reported that smoking and having 8 or more drinks a week were linked to various signs of facial aging, including under-eye puffiness.

Dark circles and under-eye bags

Chiesa Fuxench ZC, Block JK, Boguniewicz M, Boyle J, Fonacier L, et al. · J Invest Dermatol · doi:10.1016/j.jid.2018.08.028

The prevalence of atopic dermatitis among US adults was found to be 7.3%; 60.1% of patients had mild, 28.9% moderate and 11% severe disease.

Atopic dermatitis

Del Rosso JQ, Stein-Gold L, Lynde C, Tanghetti E, Alexis AF · J Drugs Dermatol

A review emphasizing that truncal acne is often overlooked and undertreated, and that scarring and discoloration are common.

Back and chest acne

Nawrocki S, Cha J · J Am Acad Dermatol · doi:10.1016/j.jaad.2018.12.071

A comprehensive review covering the causes of primary and secondary hyperhidrosis, how to tell them apart and the steps of clinical evaluation.

Excessive sweating and body odor

Soltanipoor M, Kezic S, Sluiter JK, de Wit F, Bosma AL, et al. · Contact Dermatitis · doi:10.1111/cod.13214

In healthcare workers, a one-year program encouraging cream use led to a relatively greater reduction in the severity of hand dermatitis; the effect was more noticeable in mild cases.

Hand eczema

Alinaghi F, Calov M, Kristensen LE, Gladman DD, Coates LC, et al. · J Am Acad Dermatol · doi:10.1016/j.jaad.2018.06.027

In the meta-analysis, the prevalence of psoriatic arthritis in psoriasis patients was 19.7%; among European patients, it was 22.7%.

Psoriasis

Lee YB, Byun EJ, Kim HS · Journal of Clinical Medicine · doi:10.3390/jcm8070987

Reviewed evidence that in acne the decisive factor is not a single bacterium but a loss of diversity and balance in the skin microbiome.

Oily skin

Farage MA · Frontiers in Medicine · doi:10.3389/fmed.2019.00098

Pooling surveys from around the world, found that more than half of men report some degree of sensitive skin, and that sensitivity is linked to a weakened barrier and heightened nerve responses.

Sensitive and shave-prone skin

Cloete E, Khumalo NP, Ngoepe MN · Proceedings of the Royal Society A 475:20190516 · doi:10.1098/rspa.2019.0516

Brings together why hair curls, the structure of a curly strand and its mechanical behavior, concluding that curl is a multilayered trait that starts at the hair follicle.

Wavy hairCurly hair

Baker LB · Temperature · doi:10.1080/23328940.2019.1632145

Reviewed how sweat consists largely of water and electrolytes, that its main job is temperature regulation and that it also contributes to skin defense.

Showering after a workout: what does your skin need after training?

Dréno B, Pécastaings S, Corvec S, et al. · Journal of the European Academy of Dermatology and Venereology · doi:10.1111/jdv.15043

Showed that the problem in acne is less the amount of bacteria and more the balance between subtypes and a loss of microbial diversity, which triggers inflammation by stimulating innate immunity.

AcneBack and chest acne

Juhl CR, Bergholdt HKM, Miller IM, et al. · Nutrients · doi:10.3390/nu10081049

Found a link between milk and dairy consumption and acne; however, most of the included studies were observational.

AcneBack and chest acne

Byrd AL, Belkaid Y, Segre JA · Nature Reviews Microbiology · doi:10.1038/nrmicro.2017.157

Showed that oily, moist and dry skin sites host different microbial communities, with oil-loving microbes dominating the oily areas.

Oily skin, blackheads and large poresSeborrheic dermatitis (face, eyebrows and beard)Shaving irritation (razor burn)Beard folliculitis and beard itchAtopic dermatitisHand eczemaNormal skinCombination skinPuberty20s50s60 and overAthletic menWhat is the microbiome? A short, clear guide for men

Gether L, Overgaard LK, Egeberg A, et al. · British Journal of Dermatology · doi:10.1111/bjd.16481

Calculated that rosacea occurs in 5.46% of the general adult population: 5.41% of women and 3.90% of men.

Rosacea

Gallo RL, Granstein RD, Kang S, et al. · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2017.08.037

Recommended classifying rosacea by the signs linked to the disease process (phenotype) rather than by subtypes.

Rosacea

Sakr A, Brégeon F, Mège JL, et al. · Frontiers in Microbiology · doi:10.3389/fmicb.2018.02419

Reviewed how up to 30% of people permanently carry, without symptoms, a bacterium in their nose that is often responsible for skin infections, and how this carriage can set the stage for opportunistic infections.

Beard folliculitis and beard itch

Saxena R, Mittal P, Clavaud C, Dhakan DB, Hegde P, Veeranagaiah MM, Saha S, Souverain L, Roy N, Breton L, Misra N, Sharma VK · Frontiers in Cellular and Infection Microbiology · doi:10.3389/fcimb.2018.00346

Showed that bacterial and fungal communities differ between healthy and dandruff-prone scalps and that beneficial bacteria may contribute to scalp balance.

DandruffDandruff or dry scalp? What are the flakes on your shoulders telling you?

Rahrovan S, Fanian F, Mehryan P, Humbert P, Firooz A · International Journal of Women's Dermatology · doi:10.1016/j.ijwd.2018.03.002

Reviewed evidence that men's skin produces more sebum than women's and that androgens are the key factor behind this difference.

DandruffNormal skinCombination skinPuberty20s50sWhy is men's skin different, and how does that change your routine?Testosterone, stress and skin: how do hormones show on your face?

Strazzulla LC, Wang EHC, Avila L, Lo Sicco K, Brinster N, Christiano AM, Shapiro J · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2017.04.1141

Described in detail the clinical types of alopecia areata, signs such as exclamation-mark hairs and nail changes, and accompanying conditions.

Alopecia areata

Proksch E · J Dermatol · doi:10.1111/1346-8138.14489

A review explaining the importance of the skin's acidic pH for barrier function, enzyme activity and the skin microbiome, and how alkaline cleansers can disrupt this balance.

Jock itchKeratosis pilarisHand eczema

Wang JF, Orlow SJ · Am J Clin Dermatol · doi:10.1007/s40257-018-0368-3

A review evaluating the subtypes of keratosis pilaris, associated conditions, and topical, systemic and laser treatment options.

Keratosis pilaris

Seite S, Misery L · Experimental Dermatology · doi:10.1111/exd.13686

Discussed a possible link between sensitive skin and imbalance in the skin microbiota, and noted that this area needs more research.

Sensitive and shave-prone skin

Luqman MW, Ramzan MH, Javaid U, Ali R, Shoaib M, Luqman MA · International Journal of Trichology 10(3):113-117 · doi:10.4103/ijt.ijt_115_16

Measured, in hair samples from young men, that strands treated with hard water lost significantly more tensile strength than those treated with deionized water.

Thick and dense hairDry scalp

Takagi Y, Ning X, Takahashi A, Ishizaki C, et al. · Clinical, Cosmetic and Investigational Dermatology 11:141-148 · doi:10.2147/CCID.S158428

Showed that a dry, flaky scalp has lower barrier function and ceramide levels, and that a lotion containing a ceramide-like ingredient significantly reduced dryness, flaking and itching within four weeks.

Dry scalp

Salem I, Ramser A, Isham N, Ghannoum MA · Frontiers in Microbiology · doi:10.3389/fmicb.2018.01459

Reviewed how the gut microbiome can influence skin renewal and immune responses through immune and inflammatory signals (the gut-skin axis).

Puberty

Draelos ZD · Journal of Cosmetic Dermatology · doi:10.1111/jocd.12469

Evaluated types of cleansers and the effects of surfactants on the skin barrier, emphasizing the importance of gentle cleansing.

The five-minute men's skin care routine: cleanse, moisturize, protectShowering after a workout: what does your skin need after training?

Murota H, Yamaga K, Ono E, Katayama I · Allergology International · doi:10.1016/j.alit.2018.06.003

Explained that sweat can contribute to skin hydration and defense, but depending on conditions can also trigger itching and irritation.

Showering after a workout: what does your skin need after training?

Endly DC, Miller RA · Journal of Clinical and Aesthetic Dermatology

Examined retinoids, cosmeceutical ingredients, oral treatments and procedures such as lasers for oily skin, along with their mechanisms and level of evidence.

Oily skin, blackheads and large poresOily skinOily scalp

Salman KE, Altunay IK, Kucukunal NA, Cerman AA · Anais Brasileiros de Dermatologia · doi:10.1590/abd1806-4841.20175241

Androgenetic alopecia was found in 67.1% of 419 men attending a dermatology clinic in Istanbul; frequency and severity increased with age.

Male pattern hair loss

Lolli F, Pallotti F, Rossi A, Fortuna MC, Caro G, Lenzi A, Sansone A, Lombardo F · Endocrine · doi:10.1007/s12020-017-1280-y

Summarized androgenetic alopecia as a process driven by genetic predisposition and the effect of androgens on the hair follicle, in which the follicle gradually shrinks.

Male pattern hair lossFine and thinning hairPuberty20s30sHair loss myths: hats, frequent washing and more

Reygagne P, Bastien P, Couavoux MP, Philippe D, Renouf M, Castiel-Higounenc I, Gueniche A · Beneficial Microbes · doi:10.3920/BM2016.0144

In 60 men with moderate to severe dandruff, a probiotic taken by mouth for 56 days reduced dandruff and redness compared with placebo and helped rebalance the scalp microbiota.

Dandruff

Pratt CH, King LE Jr, Messenger AG, Christiano AM, Sundberg JP · Nature Reviews Disease Primers · doi:10.1038/nrdp.2017.11

Summarized alopecia areata as an autoimmune disease that develops when the hair follicle's immune protection breaks down, usually sparing the stem cells, which is why hair can grow back.

Alopecia areata

Krutmann J, Bouloc A, Sore G, Bernard BA, Passeron T · Journal of Dermatological Science · doi:10.1016/j.jdermsci.2016.09.015

Defined how the sum of environmental factors such as sunlight, air pollution, smoking, diet and sleep determines skin aging.

Sun damage and premature agingMature skin (45+)

Plensdorf S, Livieratos M, Dada N · American Family Physician

Summarized diagnostic and treatment approaches for common pigment disorders such as sun spots, post-inflammatory marks and melasma.

Dark spots and hyperpigmentation

Nakatsuji T, Chen TH, Narala S, Chun KA, Two AM, et al. · Sci Transl Med · doi:10.1126/scitranslmed.aah4680

Beneficial bacterial strains that produce antimicrobial substances, common on healthy skin, were shown to be rare in people with atopic dermatitis, and this was linked to colonization by harmful bacteria.

Atopic dermatitis

Seité S, Zelenkova H, Martin R · Clin Cosmet Investig Dermatol · doi:10.2147/CCID.S121910

In a double-blind study of 60 patients, a moisturizer containing a harmless bacterial biomass reduced the number and severity of flares, and the skin microbiome stayed more balanced.

Atopic dermatitis

Cengiz FP, Cevirgen Cemil B, Emiroglu N, Gulsel Bahali A, Onsun N · Health Promot Perspect · doi:10.15171/hpp.2017.19

Acne located only on the trunk was reported in 6 healthy young men using whey protein to build muscle quickly.

Back and chest acne

Verma S, Madhu R · Indian J Dermatol · doi:10.4103/ijd.IJD_206_17

An appraisal of the widespread, treatment-resistant epidemic of jock itch and body ringworm in India and the role of uncontrolled corticosteroid cream use in it.

Jock itch

Callewaert C, Lambert J, Van de Wiele T · Exp Dermatol · doi:10.1111/exd.13259

An opinion paper suggesting that replacing an odor-producing armpit microbiome with a non-odor-producing one, applying probiotics and selective steering with prebiotics could be part of future odor management.

Excessive sweating and body odor

Hägg D, Sundström A, Eriksson M, Schmitt-Egenolf M · Am J Clin Dermatol · doi:10.1007/s40257-017-0274-0

In 5,438 patients, men's median psoriasis severity score (7.3) was significantly higher than women's (5.4), and the difference persisted across all age groups.

Psoriasis

Misery L, Ständer S, Szepietowski JC, Reich A, Wallengren J, Evers AW et al. · Acta Dermato-Venereologica · doi:10.2340/00015555-2397

Defined sensitive skin as the occurrence of unpleasant sensations such as stinging, burning and itching in response to stimuli that normally shouldn't cause discomfort.

Sensitive and shave-prone skin

Purnamawati S, Indrastuti N, Danarti R, Saefudin T · Clinical Medicine & Research · doi:10.3121/cmr.2017.1363

Reviewed the role of moisturizers in supporting barrier function and skin hydration.

The five-minute men's skin care routine: cleanse, moisturize, protect

Lee SJ, Seok J, Jeong SY, et al. · Dermatologic Surgery · doi:10.1097/DSS.0000000000000657

Stated that the three main causes of large pores are high sebum, loss of elasticity around the pore and increased hair follicle volume, and that treatment should be tailored to the cause.

Oily skin, blackheads and large pores

Cowley K, Vanoosthuyze K · International Journal of Cosmetic Science · doi:10.1111/ics.12330

By measuring the forces acting on skin and hair during shaving, showed that managing these forces is important for reducing irritation and inflammation.

Shaving irritation (razor burn)Sensitive and shave-prone skinShort beard / stubbleWet shave or electric shaver? Which one is easier on your skin?Why does cologne burn after shaving, and what should you use instead?Razor hygiene: small habits, comfortable skin

Rietzler M, Maurer M, Siebenhaar F, et al. · International Journal of Cosmetic Science · doi:10.1111/ics.12329

Examined the balance between effective hair cutting and skin comfort in electric shaving, as well as approaches to reduce irritation.

Shaving irritation (razor burn)

Kelly Y, Blanco A, Tosti A · Drugs · doi:10.1007/s40265-016-0629-5

Reviewed approved treatments for male pattern hair loss alongside options such as light therapy, plasma treatments and hair transplantation, together with their levels of evidence.

Male pattern hair loss

Xu Z, Wang Z, Yuan C, Liu X, Yang F, Wang T, Wang J, Manabe K, Qin O, Wang X, Zhang Y, Zhang M · Scientific Reports · doi:10.1038/srep24877

Reported that dandruff severity is closely linked to the scalp's oil and moisture levels and especially to bacterial balance.

DandruffOily scalp

Thom E · Journal of Drugs in Dermatology

Reviewed how the stress hormone may negatively affect the hair follicle's cycle and the supporting tissue around the follicle.

Telogen effluvium

Abad-Casintahan F, Chow SK, Goh CL, Kubba R, Hayashi N, Noppakun N, See J, Suh DH, Xiang LH, Kang S · The Journal of Dermatology · doi:10.1111/1346-8138.13263

Post-acne marks were found in 58.2% of 324 people who saw a dermatologist for acne; in most people the marks lasted at least a year, and picking emerged as a modifiable risk factor.

Dark spots and hyperpigmentation

Vrcek I, Ozgur O, Nakra T · Journal of Cutaneous and Aesthetic Surgery · doi:10.4103/0974-2077.184046

Summarized the pigment, vascular and structural causes of dark circles and the different treatment approaches for each.

Dark circles and under-eye bagsSleep and your under-eye area: what does one sleepless night change on your face?

Sarkar R, Ranjan R, Garg S, Garg VK, Sonthalia S, Bansal S · The Journal of Clinical and Aesthetic Dermatology

Reviewed the genetic, pigment, vascular, allergic and lifestyle factors behind darkening around the eyes, along with topical and procedure-based options.

Dark circles and under-eye bags

Weidinger S, Novak N · Lancet · doi:10.1016/S0140-6736(15)00149-X

A review covering the itchy, relapsing course of atopic dermatitis and the central role of moisturizing and inflammation control in treatment.

Atopic dermatitis

Sahoo AK, Mahajan R · Indian Dermatol Online J · doi:10.4103/2229-5178.178099

A comprehensive review covering the management of jock itch, body ringworm and athlete's foot, general measures and the importance of sticking to treatment.

Jock itch

Doolittle J, Walker P, Mills T, Thurston J · Arch Dermatol Res · doi:10.1007/s00403-016-1697-9

In a national sample of 8,160 people, the prevalence of excessive sweating was 4.8%; only 51% of those affected had discussed it with a healthcare professional.

Excessive sweating and body odorAthletic men

Urban J, Fergus DJ, Savage AM, Ehlers M, Menninger HL, et al. · PeerJ · doi:10.7717/peerj.1605

Deodorant and antiperspirant use was shown to strongly change the density and composition of armpit bacteria; when the product was stopped, bacterial density increased.

Excessive sweating and body odor

Engebretsen KA, Johansen JD, Kezic S, Linneberg A, Thyssen JP · Journal of the European Academy of Dermatology and Venereology · doi:10.1111/jdv.13301

Reviewed evidence that low humidity and cold weather weaken the skin barrier and that dryness and eczema flare-ups increase in the winter months.

Dry skin

Maurer M, Rietzler M, Burghardt R, Siebenhaar F · International Journal of Cosmetic Science · doi:10.1111/ics.12328

Described beard hair as dense, thick and coarse, and the skin around the follicles as rich in nerves, blood vessels and immune cells and able to react strongly to shaving; it also noted that men's facial skin tends to recover more slowly and to develop post-inflammatory dark spots.

Dry skinCombination skinSensitive and shave-prone skinWet shave or electric shaver? Which one is easier on your skin?Why does cologne burn after shaving, and what should you use instead?Skin care under your beard: the skin beneath matters as much as the beardRazor hygiene: small habits, comfortable skin

Keaney TC · Dermatologic Surgery · doi:10.1097/DSS.0000000000000505

Reviewed evidence that men have a thicker epidermis and dermis but lower antioxidant capacity in their skin, and that combined with smoking and poor sun protection habits, wrinkles develop more prominently in men.

Mature skin (45+)

Cruz CF, Costa C, Gomes AC, Matamá T, Cavaco-Paulo A · Cosmetics 3(3):26 · doi:10.3390/cosmetics3030026

A review of how shampooing and shape-changing treatments affect the cuticle and cortex of the hair shaft.

Wavy hairCurly hair

Dréno B, Araviiskaia E, Berardesca E, Gontijo G, Sanchez Viera M, Xiang LF et al. · Journal of the European Academy of Dermatology and Venereology · doi:10.1111/jdv.13965

Emphasized the importance of gentle cleansing and barrier-focused care in maintaining a healthy skin microbiome.

What is the microbiome? A short, clear guide for men

Tan JK, Bhate K · British Journal of Dermatology · doi:10.1111/bjd.13462

Used global data to show that acne is one of the most common skin diseases worldwide and is very frequent during adolescence.

Acne

Borda LJ, Wikramanayake TC · Journal of Clinical and Investigative Dermatology · doi:10.13188/2373-1044.1000019

Reviewed how seborrheic dermatitis and dandruff arise from the interaction of sebum, skin yeast and individual susceptibility, and that they are more common in men.

Seborrheic dermatitis (face, eyebrows and beard)DandruffPuberty40sSkin care under your beard: the skin beneath matters as much as the beardDandruff or dry scalp? What are the flakes on your shoulders telling you?

Clark GW, Pope SM, Jaboori KA · American Family Physician

Explained the typical locations of seborrheic dermatitis on the face, eyebrows and scalp, and the importance of antifungal treatment as a first-line option.

Seborrheic dermatitis (face, eyebrows and beard)

Okokon EO, Verbeek JH, Ruotsalainen JH, et al. · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.CD008138.pub3

This review of 51 studies and 9,052 participants showed that topical antifungals are more effective than placebo and can achieve effects similar to cortisone creams with fewer side effects.

Seborrheic dermatitis (face, eyebrows and beard)

Bas Y, Seckin HY, Kalkan G, Takci Z, Citil R, Önder Y, Sahin S, Demir AK · Journal of the Pakistan Medical Association

In a community screening of 2,322 people in Tokat, androgenetic alopecia was found in 47.6% of men, and its prevalence was similar to that in European populations.

Male pattern hair loss

Malkud S · Journal of Clinical and Diagnostic Research · doi:10.7860/JCDR/2015/15219.6492

Reviewed how telogen effluvium develops through a shift in the hair cycle, how shedding starts months after the trigger and often resolves on its own.

Telogen effluvium

Holman DM, Berkowitz Z, Guy GP Jr, Hawkins NA, Saraiya M, Watson M · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2015.02.1112

Found that 18.1% of men and 42.6% of women regularly applied sunscreen to their face on a sunny day.

Sun damage and premature agingNormal skinSunscreen is a must for men too: thick skin is no shield

Matsui MS, Schalka S, Vanderover G, Fthenakis CG, Christopher J, Bombarda PC, Bueno JR, Viscomi BL, Bombarda Júnior MS · Anais Brasileiros de Dermatologia · doi:10.1590/abd1806-4841.20153520

Showed that dark circles start at an average age of 24, that the most important risk factor is family history, and that the darkness comes mainly from melanin and deoxygenated blood.

Dark circles and under-eye bags

Friedmann DP, Goldman MP · Clinics in Plastic Surgery · doi:10.1016/j.cps.2014.08.007

Classified the causes of dark circles and evaluated topical products, lasers, fillers and surgical options.

Dark circles and under-eye bags

Ilkit M, Durdu M · Crit Rev Microbiol · doi:10.3109/1040841X.2013.856853

The global rise in athlete's foot was highlighted as being linked to urbanization, the spread of sports and fitness facilities, obesity and an aging population.

Athlete's foot60 and overAthletic men

Troccaz M, Gaïa N, Beccucci S, Schrenzel J, Cayeux I, et al. · Microbiome · doi:10.1186/s40168-014-0064-3

People who didn't use antiperspirant had on average 50 times more bacteria in their armpits; men's underarm odor was more intense and their bacterial load was higher.

Excessive sweating and body odor

Ibrahim O, Khan M, Bolotin D, Dubina M, Nodzenski M, et al. · JAMA Dermatol · doi:10.1001/jamadermatol.2014.2211

Three sessions of 810 nm diode laser were shown to significantly reduce roughness and the raised appearance in keratosis pilaris, while redness did not change.

Keratosis pilaris

Ying S, Zeng DN, Chi L, Tan Y, Galzote C, Cardona C et al. · PLoS One · doi:10.1371/journal.pone.0141842

Showed that the skin's bacterial community varies most by body site, and is also associated with age, gender, skin characteristics and living in an urban or rural area.

Combination skinWhat is the microbiome? A short, clear guide for men

Gavazzoni Dias MF · International Journal of Trichology 7(1):2-15 · doi:10.4103/0974-7753.153450

A comprehensive review that summarizes, from a dermatological perspective, the ingredients of hair cosmetics such as shampoos, conditioners and styling products and their effects on the hair shaft.

Straight hairWavy hairCurly hairLong and full beard

Oyetakin-White P, Suggs A, Koo B, Matsui MS, Yarosh D, Cooper KD, Baron ED · Clinical and Experimental Dermatology · doi:10.1111/ced.12455

Reported more pronounced signs of intrinsic aging and slower skin barrier recovery in women with poor sleep quality.

Sleep and your under-eye area: what does one sleepless night change on your face?

Alexis A, Heath CR, Halder RM · Dermatologic Clinics · doi:10.1016/j.det.2013.12.001

Emphasized that ingrown hairs disproportionately affect men of African descent and that treatment should combine medication, procedures and behavior changes.

Ingrown hairs (pseudofolliculitis barbae)

Laureano AC, Schwartz RA, Cohen PJ · Clinics in Dermatology · doi:10.1016/j.clindermatol.2014.02.009

Explained that bacterial infections of the face most often originate in hair follicles, and that folliculitis must be distinguished from ingrown hairs and other similar conditions.

Beard folliculitis and beard itch

Rubenstein RM, Malerich SA · Journal of Clinical and Aesthetic Dermatology

Showed that yeast folliculitis is often mistaken for acne, can be linked to antibiotic use and improves rapidly with oral antifungals.

Beard folliculitis and beard itchBack and chest acne

Wakeam E, Hernandez RA, Rivera Morales D, et al. · Journal of Hospital Infection · doi:10.1016/j.jhin.2014.02.010

Among 408 male healthcare workers, bacterial carriage on the facial skin was generally similar in bearded and clean-shaven men; some bacteria were found more often in clean-shaven men.

Beard folliculitis and beard itchLong and full beard

Callewaert C, De Maeseneire E, Kerckhof FM, Verliefde A, Van de Wiele T, Boon N · Appl Environ Microbiol · doi:10.1128/AEM.01422-14

In T-shirts collected after a workout, polyester was shown to grow different bacteria than cotton and produce a stronger, more unpleasant odor.

Back and chest acneExcessive sweating and body odor

Ely JW, Rosenfeld S, Seabury Stone M · Am Fam Physician

A practical review summarizing the diagnosis of jock itch, athlete's foot and body ringworm, how to tell them apart from similar conditions, and topical and systemic antifungal treatment options.

Jock itch

El-Gohary M, van Zuuren EJ, Fedorowicz Z, Burgess H, Doney L, et al. · Cochrane Database Syst Rev · doi:10.1002/14651858.CD009992.pub2

A Cochrane review compared the effectiveness of different groups of topical antifungals used for jock itch and body ringworm and showed that many of them are effective.

Jock itch

American Academy of Dermatology · AAD

The AAD states that when moisturizing and medicated creams aren't enough, laser and light treatments can be used to reduce redness and roughness.

Keratosis pilaris

Al-Ghazzewi FH, Tester RF · Benef Microbes · doi:10.3920/BM2013.0040

A review summarizing that prebiotics and probiotics may help support skin health by balancing the skin's microflora.

Keratosis pilaris

Behroozy A, Keegel TG · Saf Health Work · doi:10.1016/j.shaw.2014.08.001

Defined wet work as contact with water for more than 2 hours a day, wearing waterproof gloves for the same amount of time or washing hands more than 20 times per shift, and assessed it as the main risk factor for occupational hand dermatitis.

Hand eczema

Armstrong AW, Harskamp CT, Dhillon JS, Armstrong EJ · Br J Dermatol · doi:10.1111/bjd.12670

The likelihood of psoriasis was shown to be significantly higher in smokers, and smoking was shown to be an independent risk factor for developing psoriasis.

Psoriasis

Luebberding S, Krueger N, Kerscher M · Skin Research and Technology · doi:10.1111/srt.12094

Showed that skin elasticity and firmness decline with age, that the ability to bounce back after being stretched is affected most by aging, and that this change follows a different course in men and women.

Mature skin (45+)

Gavazzoni Dias MF, de Almeida AM, Cecato PM, et al. · International Journal of Trichology 6(3):95-99 · doi:10.4103/0974-7753.139078

Showed that shampoos with a pH above 5.5 can increase the negative electrical charge and friction on the hair shaft, setting the stage for cuticle damage and breakage.

Straight hairWavy hair

Ishino A, Takahashi T, Suzuki J, Nakazawa Y, et al. · British Journal of Dermatology 171(5):1052-1059 · doi:10.1111/bjd.13230

Showed through measurements that the thinning look in male pattern hair loss comes mainly not from fewer strands but from thick strands gradually becoming finer (miniaturization).

Fine and thinning hair

Chen Y, Lyga J · Inflammation & Allergy Drug Targets · doi:10.2174/1871528113666140522104422

Reviewed how psychological stress can increase skin inflammation through hormonal and nervous system signals, trigger or worsen many skin conditions, and contribute to skin aging.

20s30sTestosterone, stress and skin: how do hormones show on your face?

Luebberding S, Krueger N, Kerscher M · Skin Pharmacology and Physiology · doi:10.1159/000351349

Showed in 150 men aged 20–70 that sebum production and water loss changed little with age, whereas skin hydration on the face and neck dropped markedly and facial skin pH rose.

40s50s60 and over

Oh J, Byrd AL, Deming C, Conlan S, Kong HH, Segre JA · Nature · doi:10.1038/nature13786

Showed that oily, moist and dry areas host different communities and that an individual's microbiome is stable over time.

What is the microbiome? A short, clear guide for men

Luebberding S, Krueger N, Kerscher M · International Journal of Cosmetic Science · doi:10.1111/ics.12068

Showed that sebum production in men's skin is higher than in women's at every age and stays steady with age, and that skin pH is lower in men.

Oily skin, blackheads and large poresNormal skinDry skinOily skinCombination skinMature skin (45+)Why is men's skin different, and how does that change your routine?

Kim BY, Choi JW, Park KC, et al. · Skin Research and Technology · doi:10.1111/j.1600-0846.2011.00605.x

Showed that male sex, increased sebum and reduced skin elasticity are the factors most strongly linked to visible facial pores.

Oily skin, blackheads and large pores

Tan J, Berg M · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2013.04.043

Emphasized that rosacea epidemiology varies with diagnostic definitions and that more data are needed for populations outside Northern Europe.

Rosacea

Schwartz JR, Messenger AG, Tosti A, Todd G, Hordinsky M, Hay RJ, Wang X, Zachariae C, Kerr KM, Henry JP, Rust RC, Robinson MK · Acta Dermato-Venereologica · doi:10.2340/00015555-1382

Showed that in dandruff the scalp barrier is disrupted and inflammatory markers are increased, and that a healthy scalp can be defined by these measures.

Dandruff

Flament F, Bazin R, Laquieze S, Rubert V, Simonpietri E, Piot B · Clinical, Cosmetic and Investigational Dermatology · doi:10.2147/CCID.S44686

Suggested that visible signs of facial aging are largely determined by external factors, especially the sun, and that UV exposure may be responsible for about 80% of visible aging.

Sun damage and premature aging

Hughes MC, Williams GM, Baker P, Green AC · Annals of Internal Medicine · doi:10.7326/0003-4819-158-11-201306040-00002

Found that middle-aged men and women who used sunscreen every day had 24% less skin aging after 4.5 years than those who used it at their own discretion.

Sun damage and premature agingMature skin (45+)20s30s40s50sThe five-minute men's skin care routine: cleanse, moisturize, protectSunscreen is a must for men too: thick skin is no shield

Sundelin T, Lekander M, Kecklund G, Van Someren EJ, Olsson A, Axelsson J · Sleep · doi:10.5665/sleep.2964

Revealed that lack of sleep shows up on the face as droopy eyelids, swollen and red eyes, dark circles and pale skin, making a person look more tired.

Dark circles and under-eye bagsSleep and your under-eye area: what does one sleepless night change on your face?

Findley K, Oh J, Yang J, Conlan S, Deming C, et al. · Nature · doi:10.1038/nature12171

Mapping of 14 skin sites in ten healthy adults showed that a single group of yeasts dominates on the trunk and arms, while fungal diversity on the feet is very high.

Jock itchAthlete's foot

Callewaert C, Kerckhof FM, Granitsiotis MS, Van Gele M, Van de Wiele T, et al. · PLoS One · doi:10.1371/journal.pone.0070538

A study showing that the armpit microbiome is made up of bacterial clusters that differ from person to person and that this composition is linked to odor formation.

Excessive sweating and body odor

Brenaut E, Horreau C, Pouplard C, Barnetche T, Paul C, et al. · J Eur Acad Dermatol Venereol · doi:10.1111/jdv.12164

A systematic literature review assessed that there may be a link between alcohol consumption and psoriasis, and that alcohol may negatively affect psoriasis severity.

Psoriasis

Jensen P, Zachariae C, Christensen R, Geiker NR, Schaadt BK, et al. · JAMA Dermatol · doi:10.1001/jamadermatol.2013.722

In 60 overweight psoriasis patients, weight loss achieved through a low-calorie diet significantly improved quality of life and showed a trend toward reduced psoriasis severity.

Psoriasis

Armstrong EJ, Harskamp CT, Armstrong AW · J Am Heart Assoc · doi:10.1161/JAHA.113.000062

The meta-analysis showed that severe psoriasis in particular is associated with an increased risk of heart attack, stroke and cardiovascular death.

Psoriasis

Alekseyenko AV, Perez-Perez GI, De Souza A, Strober B, Gao Z, et al. · Microbiome · doi:10.1186/2049-2618-1-31

In 51 patients and matched controls, bacterial diversity was shown to be lower in psoriasis patches and in patients' non-affected skin, with a markedly different microbiome structure.

Psoriasis

Tsukahara K, Hotta M, Osanai O, Kawada H, Kitahara T, Takema Y · Skin Research and Technology · doi:10.1111/j.1600-0846.2011.00609.x

Showed that across all age groups men's forehead wrinkles are more pronounced than women's, and that other facial wrinkles also tend to be deeper in men up to age 65.

Mature skin (45+)

Srinivasan G, Srinivas CR, Mathew AC, Duraiswami D · International Journal of Trichology 5(3):137-139 · doi:10.4103/0974-7753.125609

Reported a slight decrease in the tensile strength of hair washed with hard water, although the difference was not statistically significant.

Straight hairDry scalp

Clavaud C, Jourdain R, Bar-Hen A, et al. · PLoS ONE 8(3):e58203 · doi:10.1371/journal.pone.0058203

Showed that on a dandruff-prone scalp the ratio between bacterial and yeast communities is disrupted compared with a healthy scalp, meaning dandruff is linked to a loss of balance.

Oily scalp

Bhate K, Williams HC · British Journal of Dermatology · doi:10.1111/bjd.12149

Reviewed evidence that acne is extremely common in adolescents, that moderate-to-severe acne affects roughly one in five young people, and that for many it continues into their 20s and 30s.

Puberty

Jinna S, Adams BB · Sports Medicine · doi:10.1007/s40279-013-0021-5

Reviewed how people who exercise outdoors are at high risk of skin cancer from UV, and how avoiding peak hours, using SPF 30 or higher, and wearing a hat, sunglasses and long sleeves reduce the risk.

Athletic men

Gatherwright J, Liu MT, Amirlak B, Gliniak C, Totonchi A, Guyuron B · Plastic and Reconstructive Surgery · doi:10.1097/PRS.0b013e3182865ca9

Showed in identical male twins that wearing a hat daily was linked to less hair loss at the temples, smoking duration and dandruff to more hair loss at the front, and long-term stress to hair loss at the crown.

Hair loss myths: hats, frequent washing and moreSmoking and skin: the bill that shows up on your face

Okada HC, Alleyne B, Varghai K, Kinder K, Guyuron B · Plastic and Reconstructive Surgery · doi:10.1097/PRS.0b013e3182a4c20a

Showed that under-eye bags and lines around the lips and mouth were more pronounced in twins who smoked.

Smoking and skin: the bill that shows up on your face

Sakuma TH, Maibach HI · Skin Pharmacology and Physiology · doi:10.1159/000338978

Reviewed how oily skin results from enlarged oil glands producing excess sebum, and how diet, age, sex and a hot, humid climate can affect oiliness.

Oily skin, blackheads and large poresOily skinCombination skin

Cowley K, Vanoosthuyze K · British Journal of Dermatology · doi:10.1111/j.1365-2133.2011.10783.x

Emphasized that skin problems caused by poor shaving practices are common but often overlooked, and that their causes are frequently misunderstood.

Shaving irritation (razor burn)Normal skinSensitive and shave-prone skinShort beard / stubblePatchy and thin beard

Draelos ZD · British Journal of Dermatology · doi:10.1111/j.1365-2133.2011.10784.x

Showed that post-shave moisturizers containing glycerin and emollients support barrier function, and that ingredients like niacinamide can strengthen this effect.

Shaving irritation (razor burn)Dry skinCombination skin

Turner GA, Hoptroff M, Harding CR · International Journal of Cosmetic Science · doi:10.1111/j.1468-2494.2012.00723.x

Showed that in dandruff, which affects up to half of the world's post-pubertal population, scalp barrier lipids are reduced and water loss is increased.

DandruffDry scalpDandruff or dry scalp? What are the flakes on your shoulders telling you?

Kong HH, Oh J, Deming C, Conlan S, Grice EA, et al. · Genome Res · doi:10.1101/gr.131029.111

During atopic dermatitis flares, skin bacterial diversity decreased and the share of an inflammation-linked bacterium increased; with treatment, diversity rose again.

Atopic dermatitis

De Luca JF, Adams BB, Yosipovitch G · Sports Medicine · doi:10.2165/11599050-000000000-00000

Reviewed how athlete's foot and body fungus, hair follicle inflammation, friction blisters, calluses and irritation are common in athletes, and how the risk of skin cancer increases in those who train in the sun for long periods.

Athletic men

Lai JJ, Chang P, Lai KP, Chen L, Chang C · Archives of Dermatological Research · doi:10.1007/s00403-012-1265-x

Reviewed the role of androgen hormones and their receptors in oil gland activity, acne, hair growth and wound healing.

Why is men's skin different, and how does that change your routine?Testosterone, stress and skin: how do hormones show on your face?

Ortiz A, Grando SA · International Journal of Dermatology · doi:10.1111/j.1365-4632.2011.05205.x

Reviewed the links between smoking and many skin conditions, including wound repair, skin aging, acne, psoriasis and hair loss.

Smoking and skin: the bill that shows up on your face

Hammer TR, Mucha H, Hoefer D · Mycopathologia · doi:10.1007/s11046-010-9347-9

Dermatophytes were shown to survive on fabric after a 30 °C home wash, while a 60 °C wash eliminated the fungus.

Jock itchAthlete's foot

Lee Y, Kim YD, Hyun HJ, Pi LQ, Jin X, Lee WS · Annals of Dermatology 23(4):455-462 · doi:10.5021/ad.2011.23.4.455

Showed that using a hair dryer very close to the hair and at high heat increases cuticle damage, while drying from about 15 cm (6 inches) away with constant movement clearly reduces the damage.

Straight hairWavy hairThick and dense hair

Manuel F, Ranganathan S · International Journal of Trichology 3(1):3-6 · doi:10.4103/0974-7753.82117

Argues that dandruff can be viewed as seborrheic dermatitis limited to the scalp and should be managed with an ongoing approach rather than a one-time fix.

Oily scalp

Bin Saif GA, Ericson ME, Yosipovitch G · Experimental Dermatology 20(12):959-968 · doi:10.1111/j.1600-0625.2011.01389.x

Reviews the nerve-, immune- and barrier-related mechanisms behind scalp itch and its most common causes.

Dry scalpSensitive scalp

Leproult R, Van Cauter E · JAMA · doi:10.1001/jama.2011.710

Showed that limiting sleep to 5 hours a night for one week markedly lowered daytime testosterone levels in healthy young men.

20sAthletic men

Paul C, Maumus-Robert S, Mazereeuw-Hautier J, Guyen CN, et al. · Dermatology · doi:10.1159/000334631

Found dry skin (xerosis) in 55.6% of 756 people aged 65 and older; advanced age, drying medications and a history of atopy increased the risk.

60 and over

Hay RJ · British Journal of Dermatology · doi:10.1111/j.1365-2133.2011.10570.x

Summarized the role of skin yeast in dandruff and seborrheic dermatitis and the clinical features of these conditions.

Skin care under your beard: the skin beneath matters as much as the beardDandruff or dry scalp? What are the flakes on your shoulders telling you?

Green AC, Williams GM, Logan V, Strutton GM · Journal of Clinical Oncology · doi:10.1200/JCO.2010.28.7078

Reported a lower incidence of melanoma in the regular sunscreen group during long-term follow-up.

Sunscreen is a must for men too: thick skin is no shield

Grice EA, Segre JA · Nature Reviews Microbiology · doi:10.1038/nrmicro2537

Showed that resident microbes can be harmless or problematic depending on conditions and that community balance is decisive.

What is the microbiome? A short, clear guide for men

Davis EC, Callender VD · The Journal of Clinical and Aesthetic Dermatology

Summarized that post-inflammatory hyperpigmentation is more common and longer-lasting in darker skin and that sun protection and brightening agents are the foundation of treatment.

Dark spots and hyperpigmentation

Mahmoud BH, Ruvolo E, Hexsel CL, Liu Y, Owen MR, Kollias N, Lim HW, Hamzavi IH · Journal of Investigative Dermatology · doi:10.1038/jid.2010.95

Showed that visible light also causes pigmentation in darker skin and that this pigmentation can be darker and longer-lasting than that from long-wavelength UVA.

Dark spots and hyperpigmentation

Axelsson J, Sundelin T, Ingre M, Van Someren EJ, Olsson A, Lekander M · BMJ · doi:10.1136/bmj.c6614

Showed that photos of sleep-deprived people were perceived as less healthy and more tired than their photos after normal sleep.

Dark circles and under-eye bags

Farage MA · Cutaneous and Ocular Toxicology · doi:10.3109/15569521003774990

Reported that men perceive overall skin sensitivity at a severity similar to women, but cite mechanical factors such as friction and contact as the cause of their sensitivity more often than women do.

Sensitive and shave-prone skin

Adams BB · Expert Review of Dermatology · doi:10.1586/edm.10.50

Reviewed bacterial, viral and fungal skin infections in athletes and hygiene measures to reduce the risk of transmission.

Showering after a workout: what does your skin need after training?

Brown SJ, Relton CL, Liao H, Zhao Y, Sandilands A, et al. · Br J Dermatol · doi:10.1111/j.1365-2133.2009.09339.x

In 792 children, filaggrin gene changes were shown to be strongly associated with findings such as keratosis pilaris, dry skin and eczema.

Keratosis pilaris

Haslund P, Bangsgaard N, Jarløv JO, Skov L, Skov R, Agner T · Br J Dermatol · doi:10.1111/j.1365-2133.2009.09353.x

A harmful, inflammation-linked bacterium was found on the hands of almost half of hand eczema patients, and its presence was significantly associated with eczema severity.

Hand eczema

Giacomoni PU, Mammone T, Teri M · Journal of Dermatological Science · doi:10.1016/j.jdermsci.2009.06.001

Reviewed how men's and women's skin differ in hormone metabolism, hair growth, sweat rate, sebum production and surface pH.

Oily skinWhy is men's skin different, and how does that change your routine?

Ghodsi SZ, Orawa H, Zouboulis CC · Journal of Investigative Dermatology · doi:10.1038/jid.2009.47

Found an acne prevalence of 94.4% among boys in 1,002 high school students with an average age of 16; a family history of acne, increased oiliness, stress and a sugary, fatty diet were associated with the risk of severe acne.

Puberty

Collier CN, Harper JC, Cafardi JA, et al. · Journal of the American Academy of Dermatology · doi:10.1016/j.jaad.2007.06.045

42.5% of men aged 20–29 and 20.1% of men aged 30–39 reported acne; acne remained a common problem well past adolescence.

Acne20s30s40s

Darcy SJ, Miller TA, Goldberg RA, Villablanca JP, Demer JL, Rudkin GH · Plastic and Reconstructive Surgery · doi:10.1097/PRS.0b013e3181811ce8

Used magnetic resonance imaging to show that fat volume in the eye socket increases with age and contributes to lower eyelid bags.

Dark circles and under-eye bags

Tan JK, Tang J, Fung K, Gupta AK, Thomas DR, et al. · J Drugs Dermatol

In 965 acne patients, acne was found on the face, chest and back in 92%, 45% and 61% respectively; truncal acne was present in more than half of patients.

Back and chest acne

Havlickova B, Czaika VA, Friedrich M · Mycoses · doi:10.1111/j.1439-0507.2008.01606.x

Superficial fungal infections were reported to affect 20-25% of the world's population, with dermatophytes being the most common cause.

Jock itch

Hwang S, Schwartz RA · Cutis

Described keratosis pilaris as an inherited condition with follicle-centered bumps on the outer arms, thighs and buttocks, and summarized that treatment is based on preventing dryness, moisturizing and keratolytics.

Keratosis pilaris

Proksch E, Brandner JM, Jensen JM · Experimental Dermatology · doi:10.1111/j.1600-0625.2008.00786.x

Described the skin barrier as a multifaceted defense system made up of physical, chemical, microbial and immune layers.

Normal skin

Misery L, Sibaud V, Ambronati M, et al. · Contact Dermatitis 58(4):234-238 · doi:10.1111/j.1600-0536.2007.01288.x

An epidemiological study in France found that a substantial share of participants described sensitive scalp symptoms such as stinging, burning and itching.

Sensitive scalp

Randall VA · Dermatologic Therapy 21(5):314-328 · doi:10.1111/j.1529-8019.2008.00214.x

Explains how, starting at puberty, androgens turn fine facial hairs into thick, pigmented beard hairs, and that this response varies by body area and by the hair follicle itself.

Long and full beardPatchy and thin beard

Lachenmeier DW · Journal of Occupational Medicine and Toxicology · doi:10.1186/1745-6673-3-26

Concluded that ethanol is generally considered safe on intact skin, while burning and irritation reactions are more likely on irritated or damaged skin.

Why does cologne burn after shaving, and what should you use instead?

Fierer N, Hamady M, Lauber CL, Knight R · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0807920105

Showed that women's hands carry a more diverse bacterial community than men's and that washing affects the community.

What is the microbiome? A short, clear guide for men

Morita A · Journal of Dermatological Science · doi:10.1016/j.jdermsci.2007.06.015

Reviewed how cigarette smoke leads to premature skin aging by increasing collagen-degrading enzymes and creating oxidative stress.

Sun damage and premature aging30s40s50sSmoking and skin: the bill that shows up on your face

Melnik B, Jansen T, Grabbe S · J Dtsch Dermatol Ges · doi:10.1111/j.1610-0387.2007.06176.x

Acne was reported to develop in about 50% of anabolic-androgenic steroid users, and this was described as an important warning sign, especially in men aged 18-26.

Back and chest acne

Crawford F, Hollis S · Cochrane Database Syst Rev · doi:10.1002/14651858.CD001434.pub2

A Cochrane review assessed that topical antifungals are effective compared with placebo for fungal infections of the skin of the foot, and evaluated differences between drug groups.

Athlete's foot

Choi EH, Man MQ, Xu P, Xin S, Liu Z, Crumrine DA et al. · Journal of Investigative Dermatology · doi:10.1038/sj.jid.5700913

Showed that the acidity of the skin's surface decreases from middle age onward and that this slows barrier repair.

Mature skin (45+)

Trüeb RM · Journal der Deutschen Dermatologischen Gesellschaft 5(5):356-365 · doi:10.1111/j.1610-0387.2007.06304.x

Examines, from a dermatological perspective, the effectiveness and possible side effects of the surfactants, conditioning agents and preservatives found in shampoos.

Straight hairThick and dense hairSensitive scalp

Loussouarn G, Garcel AL, Lozano I, et al. · International Journal of Dermatology 46(s1):2-6 · doi:10.1111/j.1365-4632.2007.03453.x

Introduced a method that classifies hair curl by measures such as curve diameter and number of waves, and showed a wide worldwide diversity ranging from straight to very tightly coiled.

Wavy hairCurly hair

Doshi DN, Hanneman KK, Cooper KD · Archives of Dermatology · doi:10.1001/archderm.143.12.1543

Reported that the twin who smoked, or had smoked longer, showed more signs of skin aging than their sibling.

Smoking and skin: the bill that shows up on your face

Roh M, Han M, Kim D, et al. · British Journal of Dermatology · doi:10.1111/j.1365-2133.2006.07465.x

Found that pore size is linked to sebum output, age and male sex, and that the relationship between sebum and pore size is stronger in men.

Oily skin, blackheads and large pores

Draelos ZD, Matsubara A, Smiles K · Journal of Cosmetic and Laser Therapy · doi:10.1080/14764170600717704

In placebo-controlled studies, niacinamide applied to the skin was seen to reduce facial sebum production and surface oil.

Oily skin, blackheads and large poresOily skin

Mukherjee S, Date A, Patravale V, Korting HC, Roeder A, Weindl G · Clinical Interventions in Aging · doi:10.2147/ciia.2006.1.4.327

Evaluated the effectiveness of topical retinoids on fine wrinkles, texture and pigmentation in photoaging, along with their side effects.

Sun damage and premature agingMature skin (45+)

Palmer CN, Irvine AD, Terron-Kwiatkowski A, Zhao Y, Liao H, et al. · Nat Genet · doi:10.1038/ng1767

Common loss-of-function gene variants of the barrier protein filaggrin were shown to be one of the major predisposing factors for atopic dermatitis.

Atopic dermatitis

Hamm H, Naumann MK, Kowalski JW, Kütt S, Kozma C, Teale C · Dermatology · doi:10.1159/000092285

Of 345 hyperhidrosis patients, 63% reported being negatively affected at work, and more than half reported moderate to severe limitations in relationships and social settings.

Excessive sweating and body odor

Marqueling AL, Gilliam AE, Prendiville J, Zvulunov A, Antaya RJ, et al. · Arch Dermatol · doi:10.1001/archderm.142.12.1611

In a series of 27 patients with the redder, more widespread 'rubra' type of keratosis pilaris, 63% were men; the cheeks, arms and legs were most commonly involved.

Keratosis pilaris

Lambers H, Piessens S, Bloem A, Pronk H, Finkel P · International Journal of Cosmetic Science · doi:10.1111/j.1467-2494.2006.00344.x

Showed that natural skin surface pH averages below 5 and that this slightly acidic environment supports the beneficial microflora living on the skin.

Normal skinStraight hairDry scalpSensitive scalpLong and full beardThe five-minute men's skin care routine: cleanse, moisturize, protectWhy does cologne burn after shaving, and what should you use instead?

Youn SW, Na JI, Choi SY, Huh CH, Park KC · Skin Research and Technology · doi:10.1111/j.1600-0846.2005.00119.x

Showed that facial sebum drops markedly from the forehead toward the cheeks and changes with the seasons, and proposed a measurable definition of combination skin.

Combination skin

Loussouarn G, El Rawadi C, Genain G · International Journal of Dermatology 44(s1):6-9 · doi:10.1111/j.1365-4632.2005.02800.x

Showed through measurements that hair density, growth rate and strand diameter vary markedly across different populations.

Thick and dense hairPatchy and thin beard

Curnier A, Choudhary S · Plastic and Reconstructive Surgery · doi:10.1097/01.prs.0000131875.67987.69

In 45 cases of rhinophyma, no significant link was found between alcohol consumption and rhinophyma.

Rosacea

Winter H, Schissel D, Parry DA, et al. · Journal of Investigative Dermatology · doi:10.1111/j.0022-202X.2004.22309.x

Used family and population studies to show that a change in a keratin gene in the hair follicle is an additional genetic risk factor for ingrown hairs.

Ingrown hairs (pseudofolliculitis barbae)

Bastiaens M, Hoefnagel J, Westendorp R, Vermeer BJ, Bouwes Bavinck JN · Pigment Cell Research · doi:10.1111/j.1600-0749.2004.00131.x

Showed that sun spots increase with age and are strongly linked to both chronic and intermittent sun exposure, as well as to sunburns before age 20.

Dark spots and hyperpigmentation

Rawlings AV, Harding CR · Dermatologic Therapy · doi:10.1111/j.1396-0296.2004.04s1005.x

Explained that natural moisturizing factor and barrier lipids are reduced in dry skin, and that moisturizers can help break this vicious cycle.

Dry skin

Ananthapadmanabhan KP, Moore DJ, Subramanyan K, Misra M, Meyer F · Dermatologic Therapy · doi:10.1111/j.1396-0296.2004.04s1002.x

Showed that harsh surfactants can damage barrier proteins and lipids, and that mild cleansing technologies reduce this effect.

Dry skin

Thiboutot D · Journal of Investigative Dermatology · doi:10.1111/j.1523-1747.2004.t01-2-.x

Explained how oil glands are regulated by hormones, above all by androgens such as testosterone and its derivatives.

Oily skin

Hadshiew IM, Foitzik K, Arck PC, Paus R · Journal of Investigative Dermatology 123(3):455-457 · doi:10.1111/j.0022-202X.2004.23237.x

Argues that the psychosocial burden of hair loss is greater than assumed and that stress can negatively affect the hair cycle.

Fine and thinning hair

Burzykowski T, Molenberghs G, Abeck D, Haneke E, Hay R, et al. · Mycoses · doi:10.1046/j.0933-7407.2003.00933.x

In a large Europe-wide survey, fungal foot disease was found in 34.9% of patients in the first study group and 40.6% in the second.

Athlete's foot

Bock M, Schmidt A, Bruckner T, Diepgen TL · Br J Dermatol · doi:10.1111/j.1365-2133.2003.05748.x

In the construction industry, the highest rate of occupational skin disease was seen in tile and mosaic workers; chromium in cement was responsible for about half of occupational allergies.

Hand eczema

Lodén M · American Journal of Clinical Dermatology · doi:10.2165/00128071-200304110-00005

Reviewed how humectant, emollient and occlusive ingredients help reduce water loss in dry skin with a weakened barrier.

Dry skin

Perry PK, Cook-Bolden FE, Rahman Z, et al. · Journal of the American Academy of Dermatology · doi:10.1067/mjd.2002.120789

Stated that ingrown hairs are a multifactorial condition in which follicle shape, hair structure and growth direction all play a role, and that prevention and early intervention are the foundation of treatment.

Ingrown hairs (pseudofolliculitis barbae)

Hakozaki T, Minwalla L, Zhuang J, Chhoa M, Matsubara A, Miyamoto K, Greatens A, Hillebrand GG, Bissett DL, Boissy RE · British Journal of Dermatology · doi:10.1046/j.1365-2133.2002.04834.x

Showed that niacinamide helps reduce skin pigmentation by suppressing the transfer of pigment to skin cells.

Dark spots and hyperpigmentation

Feldman HA, Longcope C, Derby CA, Johannes CB, et al. · Journal of Clinical Endocrinology and Metabolism · doi:10.1210/jcem.87.2.8201

Showed that in men aged 40–70, total testosterone declines by about 1.6% a year and bioavailable testosterone by 2–3%, while DHT rises, and that chronic illness, obesity and heavy drinking lower androgen levels.

40s50s

Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman MR · Journal of Clinical Endocrinology and Metabolism · doi:10.1210/jcem.86.2.7219

Showed in 890 men that testosterone declines steadily with age, independent of illness, and that low testosterone reaches a prevalence of about 20% over age 60, 30% over 70 and 50% over 80.

30s40s50s60 and over

Garg A, Chren MM, Sands LP, Matsui MS, Marenus KD, Feingold KR, Elias PM · Archives of Dermatology · doi:10.1001/archderm.137.1.53

Showed that in students under exam stress, the skin barrier repaired itself more slowly after damage.

Testosterone, stress and skin: how do hormones show on your face?

Gupta AK, Jain HC, Lynde CW, Macdonald P, Cooper EA, Summerbell RC · J Am Acad Dermatol · doi:10.1067/mjd.2000.104794

Nail fungus was confirmed in 8% of 15,000 patients; it was significantly more common in men and at older ages, and the vast majority was on the toenails.

Athlete's foot

Poskitt L, Wilkinson JD · Br J Dermatol · doi:10.1111/j.1365-2133.1994.tb03406.x

In long-term follow-up, most patients reported symptoms changing with the seasons, the arms were the most commonly affected area, and some improved with age.

Keratosis pilaris

Grove GL, Kligman AM · Journal of Gerontology · doi:10.1093/geronj/38.2.137

Showed that renewal of the outer skin layer, which takes about 20 days in young adults, lengthens by more than 10 days in later life, with the slowdown accelerating especially after age 50.

50s60 and over

Norwood OT · Southern Medical Journal · doi:10.1097/00007611-197511000-00009

Defined the Hamilton-Norwood staging still used today and classified how male pattern hair loss progresses with age.

Male pattern hair lossFine and thinning hair30s40s