Pellagra-like Dermatitis

Abstract

Three months after undergoing Roux-en-Y bariatric surgery, a 32-year-old woman presented with glossitis, angular cheilitis, and an erythematous, desquamative dermatitis with a distribution indicative of photosensitivity causing a burning sensation on her arms and around her neck (Panel A). She reported a 45-kg (100-lb) weight loss during the past four months and no diarrhea or neurologic symptoms. Pellagra was suspected because of the classic appearance of Casal's necklace (i.e., erythema, hyperpigmentation, and scales around the neck) (Panel B). Laboratory studies were notable for a plasma pyridoxine level of 0.6 ng per milliliter (2.4 nmol per liter; normal range, 5 to . . .