Alopecia in Children

True alopecia is rarely congenital; it is more often related to an inflammatory dermatosis, mechanical factors, drug ingestion, infection, endocrinopathy, nutritional disturbance, or disturbance of the hair cycle. Any inflammatory condition of the scalp, such as atopic dermatitis or seborrheic dermatitis, if severe enough, may result in partial alopecia; hair growth returns to normal if the underlying condition is treated successfully, unless the hair follicle has been permanently damaged.

TRACTION ALOPECIA.
Traction alopecia is due to trauma to hair follicles from tight braids or ponytails, headbands, rubber bands, curlers, or rollers . Children and parents must be encouraged to avoid devices that cause trauma to the hair and, if necessary, to alter the hairstyle. Otherwise, scarring of hair follicles may occur.

HAIR PULLING.
Hair pulling in childhood is usually an acute reactional process related to emotional stress. It may also be seen in trichotillomania and as part of more severe psychiatric disorders.

TRICHOTILLOMANIA.
Compulsive pulling, twisting, and breaking of hair produces irregular areas of incomplete hair loss, most often on the crown and in the occipital and parietal areas of the scalp. Occasionally, eyebrows, eyelashes, and body hair are traumatized. Some plaques of alopecia may have a linear outline. The hairs remaining within the areas of loss are of various lengths and are typically blunt tipped because of breakage. The scalp usually appears normal, although hemorrhage, crusting and chronic folliculitis may also occur.

ALOPECIA AREATA.
Alopecia areata is characterized by rapid and complete loss of hair in round or oval patches on the scalp and on other body sites. In alopecia totalis, all the scalp hair is lost ; alopecia universalis involves all body and scalp hair. The lifetime incidence of alopecia areata is 1% of the population. Over half of patients are younger than 20 yr of age.

Treatment.
This is difficult to evaluate because the course is erratic and unpredictable. The use of high-potency topical fluorinated corticosteroids with occlusion at night is effective in some patients. Intradermal injections of steroid may also stimulate hair growth locally, but this mode of treatment is impractical in young children or in those with extensive hair loss. Systemic corticosteroid therapy has, on occasion, been associated with good results; the permanence of cure is questionable, and the side effects are a serious deterrent. Additional therapies that are sometimes effective include short contact anthralin, topical minoxidil, and contact sensitization with squaric acid dibutylester or diphencyprone. In general, parents and patients can be reassured that spontaneous remission usually occurs.

New hair growth may initially be of finer caliber and lighter color, but replacement by normal terminal hair can be expected.