Alopecia, or hair loss, usually occurs on the scalp but can also occur on bearded areas, eyebrows, and eyelashes. Hair loss elsewhere on the body is less common and less conspicuous. In the nonscarring form of this disorder (noncicatricial alopecia), the hair follicle can generally regrow hair. However, scarring alopecia involves tissue destruction, such as inflammation, scarring, and atrophy, and usually destroys the hair follicle, making hair loss irreversible.
The most common form of nonscarring alopecia is male-pattern alopecia, which appears to be related to androgen levels and to aging. Genetic predisposition commonly influences the time of onset, degree of baldness, speed with which it spreads, and pattern of hair loss. Women may experience diffuse thinning over the top of the scalp.
Other forms of nonscarring alopecia include:
❑ physiologic alopecia (usually temporary): sudden hair loss in infants, loss of straight hairline in adolescents, and diffuse hair loss after childbirth
❑ alopecia areata (idiopathic form): generally reversible and self-limiting; occurs most frequently in young and middle-age adults of both sexes (See Alopecia areata.)
❑ trichotillomania: compulsive pulling out of one’s own hair; most common in children
❑ traction alopecia: localized areas of hair loss due to chronic use of tight braids (such as cornrows) or other hair styles. This condition may also result in scarring alopecia.
Predisposing factors of nonscarring alopecia also include radiation, many types of drug therapies and drug reactions, bacterial and fungal infections, psoriasis, seborrhea, and endocrine disorders, such as thyroid, parathyroid, and pituitary dysfunctions.
Scarring alopecia causes irreversible hair loss. It may result from physical or chemical trauma and chronic tension on a hair shaft, as occurs in braiding. Diseases that produce alopecia include destructive skin tumors, granulomas, lupus erythematosus, scleroderma, follicular lichen planus, and severe fungal, bacterial, or viral infections, such as kerion, folliculitis, or herpes simplex.
In male-pattern alopecia, hair loss is gradual and usually affects the thinner, shorter, and less pigmented hairs of the frontal and parietal portions of the scalp. In women, hair loss is generally more diffuse; completely bald areas are uncommon but may occur.
Alopecia areata affects small patches of the scalp but may also occur as alopecia totalis, which involves the entire scalp and eyebrows, or as alopecia universalis, which involves the entire body. Although mild erythema may occur initially, affected areas of scalp or skin appear normal. “Exclamation point” hairs (loose hairs with dark, rough, brushlike tips on narrow, less pigmented shafts) occur at the periphery of new patches. Regrowth hairs are thin and may be white or gray. They’re usually replaced by normal hair.
In trichotillomania, patchy, incomplete areas of hair loss with many broken hairs appear on the scalp but may occur on other areas such as the eyebrows.
Topical application of minoxidil, a peripheral vasodilator more typically used as an oral antihypertensive, has limited success in treating male-pattern alopecia. An alternative treatment is surgical redistribution of hair follicles by autografting. Oral finasteride has been shown to reverse androgenic loss, but it’s approved only for use in men.
In alopecia areata, minoxidil is effective, although treatment is often unnecessary because spontaneous regrowth is common. Intralesional corticosteroid injections are beneficial for small patches and may produce regrowth in 4 to 6 weeks. Anthralin, topical high-potency corticosteroids, systemic corticosteroids, topical cyclosporine, oral inosiplex, and topical nitrogen mustard all have been used in treating alopecia areata. Hair loss that persists for more than a year has a poor prognosis for regrowth. In trichotillomania, an occlusive dressing encourages normal hair growth, simply by identifying the cause of hair loss; clomipramine may be effective for short-term treatment. Treatment for other types of alopecia varies according to the underlying cause.
❑ Reassure a woman with female-pattern alopecia that it doesn’t lead to total baldness. Suggest that she wear a wig.
❑ If the patient has alopecia areata, explain the disorder and give reassurance that complete regrowth is possible.
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Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2008 Williams & Wilkins.
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Title: Professional Guide to Diseases (Eighth Edition)
Authors: Springhouse
Publisher: Lippincott Williams & Wilkins
Copyright: 2005
ISBN: 1-58255-370-X
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