Direct immunofluorescence studies in alopecia areata and male pattern alopecia.

Direct immunofluroescence studies were performed on hairy and alopecic areas of scalp in patients with alopecia areata, alopecia totalis and male pattern alopecia. Abnormal deposits of C3 and occasionally of IgG and IgM were found in 92% of 12 patients with alopecia areata and in 21% of patients with male pattern alopecia. No abnormalities were seen in 4 patients with alopecia totalis. In both alopecia areata and male pattern alopecia, the deposits were most common along the basement zone of the inferior segment of hair follicles and occurred with equal frequency in alopecic and normal scalp. These observations suggest that immune factors may play a role in the pathogenesis of alopecia areata.