Female pattern hair loss and its relationship to permanent/cicatricial alopecia: a new perspective.

Female pattern hair loss (FPHL) is a common hair disorder of the central scalp. The clinical change in hair density, related to a change in the hair cycle and miniaturization of the hair follicle, is generally considered to be potentially reversible. However, there is now evidence of a permanent hair loss that develops in a subset of women with FPHL. The presence of a perifollicular lymphohistiocytic infiltrate and fibrosis is seen without follicular drop-out in biopsies of women with FPHL and with a notable follicular drop-out in a cicatricial form of this condition (heretofore called cicatricial pattern hair loss) as well as in fibrosing alopecia in a pattern distribution, currently classified as a subset of lichen planopilaris. The potential relationship of these conditions as well as frontal fibrosing alopecia and central centrifugal cicatricial alopecia, two other conditions of permanent hair loss seen primary in women, is discussed.