Multiple Lesions at Different Stages of Pyoderma Gangrenosum in a Crohn's Disease Patient.

Pyoderma gangrenosum (PG) is an inflammatory dermatosis characterized by the rapid progression of a painful, necrolytic ulcer with an irregular and undermined border. The prevalence of PG in patients with Crohn's disease (CD) has been estimated to be 0.7%. Here, we report a case that presented various painful skin lesions, including erythema, vesicles, plaques, and ulcers, one week before the fourth infliximab infusion for CD. PG was diagnosed and the lesions subsided after a 390-mg ustekinumab infusion for one month. It suggests that different lesions of PG may occur concomitantly in CD patients, and the therapy should be re-evaluated on time.