S1C18bP8b-3: The dense fibrous tissue is rather patternless. The perivascular infiltrates contain plasma cells. Fibrosis and infiltrates of plasma cells are a common feature of some examples of folliculitis, particularly those that destroy the involved follicles. In this field, the patterns are reminiscent of keloidal acne.

S1C18bP8b-4: The patterns are of a type that might be seen in a late stage of repair, following a destructive folliculitis, as seen in the setting of the follicular occlusive disorders. Hidradenitis suppurativa is in large part a follicular occlusive disease. It should be recalled that apocrine sweat glands are in continuity with the lumens of hair follicles; if the follicle is occluded, the associated sweat duct will also be occluded.