Localized hyperkeratosis lenticularis perstans (Flegel's disease).

A case of hyperkeratosis lenticularis perstans involving only the back of a thirty-nine-year-old woman is reported. Histologic examination showed foci of compact and eosinophilic hyperkeratosis overlying a thinned stratum malpighii. In the underlying papillary dermis there was no evidence of inflammatory infiltrate. This case demonstrates that hyperkeratosis lenticularis perstans may appear as a localized disorder, and that the inflammation is not an essential pathogenic process in this disorder.