Secondary Syphilis: Clinical Features, Transmission, and Diagnostic Findings

Secondary syphilis occurs 4–10 weeks after primary chancre resolves (or overlaps). Caused by Treponema pallidum hematogenous dissemination.

Clinical Manifestations

• Mucocutaneous lesions (90%):
  • Generalized maculopapular rash (palms/soles classic — "copper penny").
  • Condylomata lata: moist, infectious papules in anogenital folds.
  • Mucous patches: snail-track ulcers in mouth, pharynx, larynx, vagina.
  • Alopecia (moth-eaten).
• Constitutional: Fever, malaise, anorexia, headache, myalgia.
• Lymphadenopathy: Generalized, non-tender; epitrochlear, axillary, inguinal prominent.
• Hepatosplenomegaly, glomerulonephritis, uveitis, meningitis (neurosyphilis).

Infectivity

Highly contagious. Lesions teem with spirochetes. Sexual, vertical, and rare occupational transmission.

Diagnostic Findings

• Serology: RPR/VDRL high titer (≥1:16); treponemal tests (FTA-ABS, TP-PA) reactive.
• Dark-field microscopy / PCR: Direct detection from lesions.
• CSF: Abnormal in ~40% (early neurosyphilis); VDRL-CSF specific but insensitive.

Natural History & Treatment

Untreated: resolves spontaneously in 4–8 weeks → early latent syphilis. Relapses in 25% (early latent). Treatment: Benzathine penicillin G 2.4 MU IM single dose (or doxycycline/tetracycline if allergic). HIV co-infection: same regimen, monitor RPR closely.