Toxigenic Corynebacterium diphtheriae–Associated Genital Ulceration

In October 2016, an adolescent boy sought care for acute genital ulceration in Cologne, Germany. We presumed a sexually transmitted infection, but initial diagnostic procedures yielded negative results. He was hospitalized because swab samples from the lesion grew toxigenic Corynebacterium diphtheriae, leading to the diagnosis of possibly sexually transmitted cutaneous diphtheria.