A case of pyoderma gangrenosum associated with ulcerative colitis treated by infliximab

Abstract

A 67-year-old woman with ulcerative colitis since 2009 was treated with infliximab (5 mg/kg), but her symptoms of ulcerative colitis were aggravated, so the amount of infliximab was increased (10 mg/kg). She then developed erythematous, edematous plaque and pustules from her left wrist to the dorsum of her hand with high-fever. Antibiotics were administered, but her symptoms became aggravated. Necrotic fasciitis was suspected from CT and MRI, and surgical debridement was done. A submitted bacterial culture, acid fast bacterial culture, and a fungal culture of the pus all came back as negative. A histological examination of a skin biopsy of necrotic tissue demonstrated neutrophilic infiltrate with leukocytoclasia and dermolysis in all of the dermis. Based on these results, we diagnosed pyoderma gangrenosum, and her symptoms have improved after we stopped the treatment with infliximab and started treatment with prednisolone. It is possible that infliximab could not suppress the development of pyoderma gangrenosum, but we should take into consideration that it might be possible that an abnormal reaction to infliximab could have occurred.