Pyoderma Gangrenosum in Ulcerative Colitis- ...left chest (Panel A) and leg (Panel B). The physical examination revealed skin ulcerations with a purulent base and an irregular purple edge. The histopathological examination of an incisional biopsy sample obtained from the chest lesion showed epidermal and superficial dermal necrosis with an underlying mixed inflammatory-cell infiltrate, abscess formation, and leukocytoclastic vasculitis. Direct microbiologic examination and cultures were negative for bacterial, fungal, and atypical mycobacterial pathogens. A diagnosis of pyoderma gangrenosum was made. Pyoderma gangrenosum is an ulcerating, inflammatory skin disorder that can be associated with an underlying systemic disease, such as ulcerative colitis. The condition is the second most common dermatologic manifestation of inflammatory bowel disease after erythema nodosum. #clinical #photo #NEJM #pyoderma #gangrenosum #ulcerative #colitis #derm