Secondary syphilis classically involves the palms and soles. Which additional feature, if present along with a maculopapular rash involving palms/soles and condylomata lata, is most diagnostic of secondary syphilis?

• A Vesicular lesions on the oral mucosa
• B Unilateral painful lymphadenopathy
• C Non-scarring patchy alopecia ('moth-eaten' alopecia) ✓
• D Punched-out oral ulcers with undermined edges

Explanation

Secondary syphilis causes non-scarring moth-eaten (alopecia areolaris) or diffuse alopecia due to perivascular plasma cell infiltrate around hair follicles. This pattern is nearly pathognomonic when combined with the palmoplantar rash. Condylomata lata are flat wart-like lesions in moist intertriginous areas (different from acuminate condylomas of HPV). Vesicular lesions are NOT a feature of secondary syphilis. Painful lymphadenopathy is characteristic of chancroid.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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