A Young Patient with Painful Penile Lesions.

Chancroid is a rare infection in the United States and many other developed countries. Infrequently identified as a cause of genital ulcer disease, chancroid's atypical presentation has only been reported in approximately 20 cases annually in the United States since 2011. Infection with the causative organism, Haemophilus ducreyi, leads to an erythematous papule that rapidly evolves into a pustule. Infected individuals commonly have more than one ulcer about 2 cm in diameter that is typically noted as painful. The base of the ulcer is usually covered with a gray or yellow purulent exudate and bleeds when scraped. Despite a heavy focus in preclinical medical education, the notably rare chance to see and diagnose chancroid in clinical practice adds to the complicated profile of this infection's identification and subsequent treatment. Such lack of familiarity contributes to reports of accuracy of clinical diagnosis ranging from 30% to 80%.