Failure of Benzathine Penicillin in a Case of Seronegative Secondary Syphilis in a Patient With Acquired Immunodeficiency Syndrome: Case Report and Review of the Literature

We report a case of secondary syphilis in a patient with human immunodeficiency virus (HIV) and negative serologic test findings who did not respond to initial therapy with benzathine penicillin. A skin biopsy specimen prepared with Warthin-Starry stain revealed spirochetes and led to the appropriate treatment and resolution of symptoms.

A 39-year-old black woman presented to the infectious diseases clinic with a 3- to 4-week history of a painless, pruritic eruption that had begun in her perianal area and extended anteriorly onto her vulva. The patient had been diagnosed with HIV in 1996; her most recent CD4 count and HIV RNA viral load were 81 × 10⁶/L and 191 000 copies/mL, respectively. She acknowledged poor adherence to her antiretroviral medication regimen.