Prurigo pigmentosa (Nagashima) associated with anorexia nervosa.

Prurigo pigmentosa (Nagashima), which is not rare in Japan, is an inflammatory disease of unknown aetiology. The characteristic lesions are pruritic red papules, superseded by reticular hyperpigmentation, characteristically on the back, neck, and chest. We now report a case of prurgio pigmentosa associated with anorexia nervosa. These findings suggest that the ketosis produced by anorexia nervosa may well contribute to the pathogenesis of prurigo pigmentosa.