An HIV-positive man with painless ulcer and pustules: mpox, syphilis, or both?

Mpox (formerly monkeypox) is a viral illness endemic in certain parts of the world such as Africa. Travel to these endemic areas has increased outbreaks in regions typically unaffected by this poxvirus. Mpox infection is characterized by prodromal symptoms including fever, chills, and lymphadenopathy, followed by a vesiculopustular exanthem. Genital lesions are common especially in vulnerable populations, such as those who engage in high-risk sexual behaviors. We report a 50-year-old man living with HIV who presented for evaluation of multiple painless genital lesions and later tested positive for both mpox and syphilis. With recent outbreaks, clinicians should evaluate genital lesions with a broad sexually transmitted infection differential. Rapid diagnosis and treatment are imperative to prevent more severe disease progression in immunocompromised patients.