The Prozone phenomenon in a 25-year-old HIV-positive male with ocular syphilis and allergy to penicillin
2nd World Conference on STDs, STIs & HIV/AIDS
May 18-19, 2018 | Montreal, Canada
Lee-Boyd D. Valencia and Ryan M. Llorin
St. Luke’s Medical Center, Philippines
Posters & Accepted Abstracts : Virol Res J
Abstract:
The incidence of syphilis is increasing especially among MSM with HIV. However because of its multitudinous unusual manifestations, it remains a diagnostic and therapeutic challenge to the modern era. The case presents a 25-year-old homosexual male, recently-diagnosed with HIV who presented with progressive blurring of vision following a history of pruritic rashes on both lower extremities. Physical examination shows madarosis, hyperemic conjunctivae with multiple erythematous macules and papulovesicular lesions with some collarette scaling over both lower extremities. During an initial consultation, the Rapid Plasma Reagin (RPR) was negative with a CD4 count was 34cells/ mm3. The persistence of symptoms prompted consult to an infectious disease specialist and subsequent referral to an ophthalmologist. Funduscopy showed a clear media and hyperemic disc with indistinct disc borders. There are multiple whitish dots in the retinal mid-periphery. Fluorescin angiography showed leakage of the optic nerve head with diffuse areas of retinal vasculitis in the retinal mid periphery. A repeat RPR was remarkably reactive at 1:256. The false negative result during the initial non-treponemal test therefore demonstrated the Prozone phenomenon which occurs in <1% of cases when high titers of antibodies interferes with the proper formation of the antigen-antibody lattice network. The history, self-report of unprotected sexual intercourse and the correlation between rashes, several diagnostic findings, and a positive Fluorescent treponemal antibody absorption test yield the diagnosis of ocular syphilis. Treatment of penicillin G 24M units IV daily for 14 days was intended. But because of a known history of penicillin allergy, oral desensitization with penicillin V was initiated first. In conclusion, clinicians need to remain familiar with the protean manifestations of syphilis and acquainted with Prozone effect when necessary. Since syphilis is a great masquerader, it requires high index of suspicion and should be included in the differential diagnoses of visual complaints. e: leeboydvalenciamd@gmail.com
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