Corroborative evidence that alopecia areata involves the epidermis and the sebaceous glands.

By using combined autoradiography and computerized image analysis, keratinocytes, sebaceous cells, and endothelial cells of the papillary dermis appear affected in alopecia areata. The atrophy and the reduction in the number of cells synthesizing DNA in these tissues resemble the changes observed in the hair follicles.