A clinicopathological study of Flegel's disease (hyperkeratosis lenticularis perstans).

The clinical and histopathological features of 12 female patients with Flegel's disease were studied. The onset of this dermatosis was delayed until adulthood. The eruption consisted of scaly papules 1-5 mm in diameter which developed principally on the lower legs, upper arms and pinnae. Histopathologically there were discrete foci of hyperkeratosis with some parakeratosis over an attenuated and partially spongiotic epidermis. A genetic influence in this disorder was suggested by its occurrence in sisters in two families and in a mother and daughter. Immunohistochemical and biochemical studies suggested that there is a disorder of keratinocyte proliferation in the disease.