Which test confirms the suspected diagnosis of secondary syphilis?

• A. VDRL
• B. Patch testing
• C. Acetowhitening
• D. Gram stain and culture

Answer: (A)

Non-treponemal serologic testing is what builds the case for syphilis in someone with compatible symptoms, especially in the secondary stage when antibody levels are high. The VDRL detects reagin antibodies to cardiolipin and is commonly used to screen for syphilis and to monitor treatment response because titers reflect disease activity. A positive VDRL in the right clinical context strongly supports the diagnosis, but it isn’t specific for Treponema pallidum. To firmly confirm the infection, a treponemal-specific test such as FTA-ABS or TPPA should be performed, because these tests detect antibodies specifically directed against the bacterium. The other options don’t pertain to syphilis testing: patch testing is for allergic contact dermatitis; acetowhitening is used in screening for cervical neoplasia or HPV-related changes; Gram stain and culture are for bacterial infections and do not diagnose syphilis. In short, a reactive non-treponemal test like VDRL supports the diagnosis and is typically followed by a treponemal confirmatory test.