A 32-year-old woman from Mumbai presents with a maculopapular rash on the trunk and extremities, including the palms and soles. She also has condyloma lata in the perianal region, mucous patches in the mouth, and generalized lymphadenopathy. Serological tests show high-titre RPR and positive FTA-ABS. Which is the most common systemic manifestation of secondary syphilis?

## Most Common Systemic Manifestation of Secondary Syphilis **Key Point:** Generalized lymphadenopathy is the most common systemic manifestation of secondary syphilis, occurring in 50–80% of patients. ### Frequency of Systemic Manifestations in Secondary Syphilis | Manifestation | Frequency | Clinical Features | |---|---|---| | Generalized lymphadenopathy | 50–80% | Non-tender, mobile, rubbery nodes; epitrochlear involvement characteristic | | Rash (maculopapular) | 75–90% | Involves palms and soles; non-pruritic | | Mucous patches | 20–30% | Painless erosions on oral mucosa and genital surfaces | | Condyloma lata | 5–10% | Hypertrophic lesions in intertriginous areas | | Hepatosplenomegaly | 5–10% | Mild to moderate enlargement; hepatitis rare | | Neurosyphilis | 1–2% | Asymptomatic in most; symptomatic meningitis rare | | Ocular involvement | <1% | Anterior uveitis, interstitial keratitis (rare in secondary stage) | ### Clinical Presentation of Generalized Lymphadenopathy in Secondary Syphilis **High-Yield:** The lymphadenopathy in secondary syphilis has distinctive features: 1. **Generalized distribution** — involves cervical, axillary, inguinal, and epitrochlear nodes 2. **Non-tender** — unlike suppurative lymphadenitis 3. **Mobile and rubbery** — firm consistency 4. **Epitrochlear involvement** — highly characteristic of syphilis; rarely seen in other conditions 5. **Persistent** — may last weeks to months **Clinical Pearl:** The presence of **epitrochlear lymphadenopathy** (nodes above the elbow on the medial aspect of the arm) is a classic sign of secondary syphilis and should always raise suspicion for syphilis. ### Rash in Secondary Syphilis **Key Point:** The rash is the most visible manifestation and occurs in 75–90% of patients, but lymphadenopathy is more universally present as a systemic sign. **Mnemonic: SYPHILIS rash — Symmetric, Year 2 (secondary), Palms/Soles involved, Highly infectious, Indurated papules, Lymphadenopathy, Involves trunk and extremities, Serological positivity.** ### Why Lymphadenopathy is Most Common 1. **Immune response** — *T. pallidum* disseminates widely; regional and generalized lymph nodes mount a robust response 2. **Timing** — lymphadenopathy appears early in secondary syphilis and persists throughout the stage 3. **Pathology** — histology shows follicular hyperplasia and plasma cell infiltration 4. **Clinical significance** — present in nearly all untreated secondary syphilis cases ### Distinction from Other Systemic Manifestations **Warning:** Do not confuse the frequency of rash (visible in 75–90%) with the frequency of lymphadenopathy (present in 50–80% as a systemic manifestation). The question asks for "systemic manifestation," and lymphadenopathy is the most common systemic sign. ### Serological Correlation **High-Yield:** The high-titre RPR (often >1:16) and positive FTA-ABS confirm secondary syphilis. The RPR titre correlates with disease activity and spirochete burden. [cite:Harrison 21e Ch 207]