The actinic cheilitis of hereditary polymorphic light eruption.

Sixty-four North American Indians with hereditary polymorphic light eruption (HPLE), or a family history of HPLE, had chronic, recurrent, exudative, and exfoliative cheilitis. Fifty-two had the cheilitis by the age of 10 years. Microscopically, the epithelium was either thickened, or thinned and covered by a thick crust. The dermis had a dense infiltration of inflammatory cells, mostly lymphocytes and plasma cells. The condition was not premalignant. The HPLE has to be differentiated from the chronic actinic cheilitis caused by long exposure to sunlight with out any element of hypersensitivity. The latter is potentially premalignant. Chronic recurrent actinic cheilitis associated with hereditary polymorphic light eruption appears to be a specific characteristic of photosensitivity occurring in American Indians. Plasma cell infiltration is not specific for either type of cheilitis.