Alopecia

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

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

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

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

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