Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT PART 6-54: Alopecia + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis +++ Forms of hair loss ++ Scarring (suggested by absent follicular markings) Nonscarring (suggested by present follicular markings) +++ General Considerations +++ Scarring ++ Irreversible and permanent, thus it is important to treat the scarring process as early as possible May occur following Chemical or physical trauma Bacterial or fungal infections Severe herpes zoster Chronic discoid lupus erythematosus Scleroderma Excessive ionizing radiation Specific dermatologic diseases of the scalp that result in scarring alopecia include Lichen planopilaris Frontal fibrosing alopecia Dissecting cellulitis of the scalp Folliculitis decalvans The specific cause is often suggested by The history The distribution of hair loss The appearance of the skin, as in lupus erythematosus +++ Nonscarring ++ May occur in association with various systemic diseases such as Systemic lupus erythematosus Secondary syphilis Hyperthyroidism or hypothyroidism Iron deficiency anemia Vitamin D deficiency Pituitary insufficiency +++ Androgenetic alopecia ++ Both men and women are affected, often starting in the third decade +++ Telogen effluvium ++ A transitory increase in the number of hairs in the telogen (resting) phase of the hair growth cycle Causes Spontaneous occurrence Iron deficiency May appear at the termination of pregnancy Precipitated by "crash dieting," high fever, stress from surgery or shock, or malnutrition Provoked by hormonal contraceptives Latent period of 2–4 months The prognosis is generally good +++ Alopecia areata ++ Unknown cause but is believed to be an immunologic process (autoimmune) Occasionally associated with Hashimoto thyroiditis, pernicious anemia, Addison disease, and vitiligo + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs +++ Androgenetic alopecia ++ In men, the earliest changes occur at the anterior portions of the calvarium on either side of the "widow's peak" and on the crown (vertex) In women, there is retention of the anterior hairline while there is diffuse thinning of the vertex scalp hair and a widening of the part The extent of hair loss is variable and unpredictable +++ Alopecia areata ++ Typically, there are patches that are perfectly smooth and without scarring Tiny hairs 2–3 mm in length, called "exclamation hairs," may be seen Telogen hairs are easily dislodged from the periphery of active lesions The beard, brows, and lashes may be involved Involvement may extend to all of the scalp hair (alopecia totalis) or to all scalp and body hair (alopecia universalis) +++ Differential Diagnosis ++ Scarring (cicatricial) Chemical or physical trauma Lichen planopilaris Bacterial or fungal infection Herpes zoster (shingles) (severe) Discoid lupus erythematosus Scleroderma Excessive ionizing radiation Nonscarring Androgenic (male pattern) baldness Telogen effluvium Alopecia areata Trichotillomania Drug-induced alopecia Systemic lupus erythematosus Secondary syphilis Hyperthyroidism Hypothyroidism Iron deficiency anemia Vitamin D deficiency Pituitary insufficiency + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Serum testosterone, DHEAS, iron, total iron-binding capacity, and thyroid function tests and a complete blood count will identify most other causes of hair thinning in premenopausal women +++ Telogen effluvium ++ Diagnosed by the presence of large numbers of hairs with white bulbs coming out upon gentle tugging Counts of hairs lost on combing or shampooing often exceed 150 per day, compared with an average of 70–100 +++ Diagnostic Procedures ++ Biopsy is useful in the diagnosis of scarring alopecia, but specimens must be taken from the active border and not from the scarred central zone + Treatment Download Section PDF Listen +++ +++ Medications +++ Androgenetic alopecia ++ Minoxidil 5% solution once daily Available over the counter Recommended for persons with recent onset (< 5 years) and smaller areas of alopecia Approximately 40% of patients treated twice daily for 1 year will have moderate to dense growth Finasteride (Propecia) In men, 1 mg daily orally has similar efficacy to minoxidil May be added to minoxidil Contraindicated in women who are or may become pregnant, but otherwise may be given in doses up to 2.5 mg/day orally +++ Hair loss or thinning in women ++ May be treated with topical minoxidil +++ Telogen effluvium ++ If iron deficiency is suspected, a serum ferritin should be obtained, and a low value followed by iron supplementation +++ Alopecia areata ++ Intralesional corticosteroids are frequently effective Triamcinolone acetonide in a concentration of 2.5–10 mg/mL is injected in aliquots of 0.1 mL at approximately 1- to 2-cm intervals, not exceeding a total dose of 30 mg per month for adults Oral JAK inhibitors (ruxolitinib, tofacitinib) Therapeutic options for patients with highly morbid disease However, relapse is the rule once the medication has been stopped +++ Therapeutic Procedures +++ Scarring ++ Prompt and adequate control of the underlying disorder; usually leads to regrowth of hair +++ Alopecia areata ++ Usually self-limiting, with complete regrowth of hair in 80% of patients, but some mild cases are resistant Support groups for patients with extensive alopecia areata are very beneficial +++ Androgenetic alopecia ++ Platelet rich plasma is an emerging therapy + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ Women who complain of thin hair but show little evidence of alopecia need follow-up, because more than 50% of the scalp hair can be lost before the clinician can perceive it +++ Complications ++ Scarring alopecia can be very disfiguring +++ When to Refer ++ All scarring alopecias except clearly diagnosed discoid lupus erythematosus and posttraumatic Diagnosis and management questions + References Download Section PDF Listen +++ + +Adil A et al. The effectiveness of treatments for androgenetic alopecia: a systematic review and meta-analysis. J Am Acad Dermatol. 2017 Jul;77(1):136–41.e5. [PubMed: 28396101] + +Ciechanowicz P et al. JAK-inhibitors in dermatology: current evidence and future applications. J Dermatolog Treat. 2019 Nov;30(7):648–58. [PubMed: 30433838] + +Jones G et al. Assessment and treatment of trichotillomania (hair pulling disorder) and excoriation (skin picking) disorder. Clin Dermatol. 2018 Nov–Dec;36(6):728–36. [PubMed: 30446196] + +Lee S et al. Management of alopecia areata: updates and algorithmic approach. J Dermatol. 2017 Nov;44(11):1199–211. [PubMed: 28635045] + +Santos LDN et al. What's new in hair loss. Dermatol Clin. 2019 Apr;37(2):137–41. [PubMed: 30850035] + +Strazzulla LC et al. Alopecia areata: disease characteristics, clinical evaluation, and new perspectives on pathogenesis. J Am Acad Dermatol. 2018 Jan;78(1):1–12. [PubMed: 29241771] + +van Zuuren EJ et al. Interventions for female pattern hair loss. Cochrane Database Syst Rev. 2016 May 26;(5):CD007628. [PubMed: 27225981]