Infliximab-induced amicrobial pustulosis of the folds in a patient with Crohn disease.

Tumor necrosis factor (TNF) inhibitors may paradoxically induce pustular eruptions, most of which are classified as pustular psoriasis. Amicrobial pustulosis of the folds (APF) is a much rarer entity that was recently recognized to occur in the setting of chronic anti-TNF therapy and inflammatory bowel disease, with 12 existing cases in the literature. Amicrobial pustulosis of the folds is a neutrophilic dermatosis characterized by aseptic pustules involving the major and minor skin folds, genital regions, and scalp. Herein, we report an additional case of paradoxical APF induced by chronic infliximab therapy in a patient with Crohn disease.