Follicular psoriasis.

This is a report on ten patients with follicular psoriasis. Two distinct clinical types could be distinguished. An adult form, seen especially in women, presented with widespread psoriasis in which follicular lesions occurred on both thighs as part of the efflorescence. Follicular lesions were aggregated to form isolated asymmetrical plaques on the trunks of children with inactive psoriasis. The histological findings in follicular psoriasis varied according to the age of the lesion. In the early lesion there was a marked dermal infiltrate in which the mast cells were prominent but the hair follicle appeared normal. Older lesions were found to have nucleated cells in the ostium of the follicle. These findings suggest that the hair follicle may be affected as part of psoriatic involvement of the integument.