Pseudopelade of Brocq.

41 cases with scarring alopecia seen from 1979 to 1983 were analyzed and differentiated. After exclusion of 7 cases with lichen planopilaris, of 5 cases with discoid lupus erythematosus, of 2 cases with scleroderma, and of 1 case with folliculitis decalvans, there remained 26 cases. The clinical histological and direct immunofluorescence (DIF) findings in these patients suggest that pseudopelade of Brocq might be a distinct disease unrelated to other known types of scarring alopecia. The histopathology is characteristic, and shows the following features: little or only moderate lymphocytic infiltrate, absence of significant follicular plugging, and absence or decrease of sebaceous glands. DIF is negative, occasionally only IgM can be found at the basement membrane. The course of the disease is slowly progressive (in spite of little or no visible erythema), becoming eventually stationary after several years and resulting in a more or less severe permanent hair loss.