title: Erthropoietic protoporphyria: first report of cases in the American Nergo.
abstract: The first two cases of erthropoietic protoporphyria in the American Nergo are reported. The eruption was limited to the lips, subungual and periungual areas, which are relatively nonpigmented. Onset was at a later age and length of sun exposure required to produce symptoms was longer than that in most whites with the disease. The different presentation in Negroes is believed to be related to their increased pigmentation. Melanin appears to provide protection because of its free radical formation and absorption of 400 nm electromagnetic radiation.
mesh_terms: D000293:Adolescent; D000328:Adult; D044383:Black People; D004920:Erythropoiesis; D005260:Female; D006801:Humans; D008297:Male; D011164:Porphyrias / Q000453:epidemiology* / Q000235:genetics; D011166:Porphyrins / Q000097:blood*; D011524:Protoporphyrins / Q000097:blood*; D014481:United States; D001741:Black or African American
chemical_list: D011166:Porphyrins; D011524:Protoporphyrins