Syphilis, leprosy, and human immunodeficiency virus coinfection: a challenging diagnosis

The association between syphilis, leprosy, and human immunodeficiency virus (HIV) is not well documented, and the emergence of isolated cases raises the interest and indicates that this triple coinfection can occur. We report the case of a 42-year-old man from Rio de Janeiro, Brazil, who presented with erythematous papules on the trunk, back, and upper and lower extremities; an erythematous plaque on the upper abdomen; and an erythematous violaceous plaque on the right thigh with altered sensitivity. Laboratory investigation showed a reagent VDRL test (1:512) and positive test results for Treponema pallidum hemagglutination. Treatment with benzathine penicillin (2,400,000 U intramuscularly) was started (2 doses 1 week apart). On follow-up 40 days later, the lesions showed partial improvement with persistence of the plaques on the right thigh and upper abdomen as well as a new similar plaque on the back. Further laboratory examinations showed negative bacilloscopy, positive HIV test, and histologic findings consistent with tuberculoid leprosy. The patient was started on multidrug therapy for paucibacillary leprosy with clinical improvement; the patient also was monitored by the HIV/AIDS department. We emphasize the importance of clinical suspicion for a coinfection case despite the polymorphism of these diseases as well as the precise interpretation of laboratory and histopathology examinations to correctly manage atypical cases.