Generalized Lichen Nitidus in a boy with Niemann-Pick disease type B
A 12-year-old boy presented with a 12-month history of asymptomatic papules that first\nappeared on his shoulders and gradually spread to involve most of the skin surface. The\npatient had Niemann-Pick disease type B, confirmed by genetic study at the age of 4.\nHepatosplenomegaly and dyslipidaemia were the main manifestations of the disease. He has\nbeen in the 10th percentile for both weight and height. His neurological state and\nintellectual ability were normal. There was no history of consanguinity between his\nparents. His 16 year-old sister was also affected by Niemann-Pick disease, although\nwithout any cutaneous manifestations.\nOn physical examination, there were numerous discrete, skin-coloured, flat-topped,\nmonomorphic, pinhead-sized papules grouped over the abdomen, umbilicus, trunk, penile\nshaft, upper extremities, knees and malleolar regions. On the lower back some of the\nlesions were grouped in linear array, possibly as a result of the Koebner phenomenon\n(). The face, oral mucosa and\npalmoplantar surfaces were not involved.\nHistopathological examination revealed a well circumscribed, lymphohistiocytic\ngranulomatous infiltrate in the papillary dermis. This infiltrate appeared to be\nclutched by elongated epidermal ridges resembling a "ball and claw" pattern (). The clinicopathological picture was\nentirely in-keeping with lichen nitidus.