[Diagnosis and therapy of alopecia areata].

In general, the diagnosis of alopecia areata is not difficult. In children, we have to consider trichotillomania as a differential diagnosis; in adult patients pseudopelade and syphilis have to be taken into account. Investigation of the nails may support the diagnosis and help to assess the degree of activity of the disease. The efficacy of topical immunotherapy using diphencyprone or squaric acid dibutylester has been proved by various study groups. Unilateral comparative studies supported our assumption that the therapeutic response is most probably due to a local immunomodulation. The applicability of this method is limited by the fact that the toxicological data available on the contact allergens used are still incomplete.