Concurrent Erythema Nodosum and Pyoderma Gangrenosum in a Patient with Inflammatory Bowel Disease Unclassified

Abstract

Purpose: Previous studies have shown that up to 40% of patients with Inflammatory Bowel Disease (IBD) may develop extraintestinal manifestations (EIMs) with skin manifestations being one of the most common. Although erythema nodosum (EN) and pyoderma gangrenosum (PG) are the two most common skin EIMs of IBD, there have been few studies documenting the presence of both EN and PG in the same patient, and no studies documenting the presence of EN, PG and psoriasis in the same patient. Multivariable analyses have shown significant predictive associations between EN and PG. IBD has traditionally been classified into either CD or ulcerative colitis (UC), but a 3rd subgroup of patients, eventually labeled as IBD Unclassified (IBDU), was defined as those who could not be classified as having either CD or UC despite comprehensive diagnostic tests. We report a Caucasian male with IBDU complicated by numerous EIMs including psoriasis, PG, and deep venous thrombi who presented with new indurated plaques and nodules over his upper and lower extremities. These erythematous lesions were purple, tender, and more prominent on the anterior shins. Of note, seven months prior to this rash, he had PG of the left shin that improved with intravenous infliximab treatment. Regarding the patient's IBD history, he was initially diagnosed with ulcerative colitis (UC). However, because he had atypical features including aphthous ulcerations, anorectal strictures, and an indeterminate IBD serology panel, his diagnosis was changed to IBDU. The patient was admitted for further work up of this new skin rash. The dermatology service performed a skin biopsy that was consistent with EN. He was started on steroids and his lesions improved. To our knowledge, the occurrence of both EN and PG has not been described among IBDU patients. Furthermore, our case report may be the first describing an IBD patient with three types of inflammatory skin lesions - EN, PG, and psoriasis.Figure: [1571] Figure A. EN of the lower extremity. Figure B. Healing PG of the lower extremity.