(1997; 132 pages) [French] [Spanish]
Alopecia areata, which is presumed to be immunologically mediated, is a relatively common disease that affects the hair. It is characterized by one or more oval or circular patches of non-scarring hair loss on an otherwise normal scalp. When the disease is active, hairs at the margins of these patches may be removed by light traction. Diffuse thinning of hair sometimes occurs in the early stages and in severe cases the lesions may extend, resulting ultimately in total hair loss. Diffuse fine pitting of the nails has been reported in over half the patients presenting with alopecia areata.
Alopecia areata most often appears in childhood or early adult life but it can occur at any age. In some patients there is a family history. In two-thirds of the cases, partial or complete regrowth of hair occurs within 5 years. After this time spontaneous recovery is unusual. Patchy hair loss is seen in secondary syphilis, but it is usually easily differentiated by history, other physical findings, and a more irregular “moth-eaten” appearance. Tinea capitis may also cause patchy hair loss, particularly in children.
The response to treatment is uncertain and beneficial results are often short-lasting. It has been claimed that early treatment may limit extension of the lesions, while untreated cases become unresponsive. Drug therapy is rarely warranted in children and adolescents, or when the condition is stable. In patients with extensive hair loss, a wig or partial hairpiece provides a more satisfactory solution.
Localized regrowth of hair may be stimulated by application of a topical corticosteroid such as hydrocortisone acetate or of a keratolytic agent such as dithranol or tretinoin. Systemic corticosteroids are rarely (if ever) used, given their dangers and the uncertain response, and the recurrence of hair loss after they are discontinued. PUVA therapy is sometimes effective in unresponsive cases.