Secondary Syphilis

Secondary syphilis is the disseminated stage of infection by Treponema pallidum, appearing 4 to 10 weeks after the chancre, when spirochaetes spread through the blood to skin, mucosa, lymph nodes and organs. It is highly infectious through mucocutaneous lesions.

• Occurs in untreated or inadequately treated primary syphilis, and often in people with HIV.
• Untreated infection in pregnancy causes congenital syphilis.

Generalised, symmetrical, non itchy macular or papular rash including the palms and soles, with fever, malaise, sore throat, generalised lymphadenopathy, patchy alopecia (moth eaten), and mucous patches.

• Condylomata lata (moist grey white plaques in warm folds, genitals and perianal skin), snail track oral ulcers.
• Systemic: hepatitis, glomerulonephritis (nephrotic syndrome), periostitis, uveitis, meningitis, cranial neuropathies.
• Differential diagnosis: pityriasis rosea, drug eruption, viral exanthema, acute HIV infection, tinea versicolor, psoriasis, lichen planus, measles, rubella, infectious mononucleosis, scabies, leprosy, genital warts (versus condylomata lata).
• Complications: neurosyphilis, ocular syphilis, otosyphilis, syphilitic hepatitis, nephropathy, progression to latent and tertiary disease, congenital syphilis, increased HIV transmission.

Serology with treponemal and non treponemal tests.

• Non treponemal (RPR or VDRL) titres usually at least 1 in 32; treponemal tests (TPHA, TPPA, EIA or rapid immunochromatographic test) are positive; prozone phenomenon can cause false negative RPR in very high titres (request dilution).
• Dark field microscopy or PCR of condylomata lata or mucous patch scrapings.
• HIV test, hepatitis B and C, gonorrhoea, chlamydia; urinalysis; CSF examination and ophthalmological review if neurological, visual or hearing symptoms.

Single intramuscular benzathine penicillin is curative for early syphilis.

• Supportive: counselling, abstinence from sex until lesions heal and 7 days after treatment, partner notification (all partners within the past 90 days) with presumptive treatment, condoms, HIV and STI screening, vaccination for hepatitis B, warn of Jarisch Herxheimer reaction.
• Pharmacological: benzathine benzylpenicillin 2.4 million units IM single dose (children 50,000 units/kg up to 2.4 million units). Penicillin allergy (non pregnant): doxycycline 100 mg twice daily for 14 days; alternatively ceftriaxone 1 g IM or IV daily for 10 days. Pregnancy: penicillin only (desensitise if allergic), with a second dose after 1 week if the woman is in the third trimester. Jarisch Herxheimer reaction (fever, myalgia within 24 hours): paracetamol 1 g, fluids. Neurosyphilis or ocular syphilis: benzylpenicillin 18 to 24 million units daily IV (3 to 4 million units every 4 hours) for 10 to 14 days.
• Procedures: lumbar puncture when neurological, ocular or otic features are present or treatment fails.
• Special groups: pregnancy, penicillin to prevent congenital syphilis and neonatal evaluation; HIV, give benzathine benzylpenicillin 2.4 million units IM, with closer serological follow up and consider CSF examination; infants and children, evaluate for congenital syphilis and abuse; penicillin allergy, skin testing and desensitisation.
• Red flags: headache, neck stiffness, visual loss, hearing loss, cranial nerve palsy, pregnancy, treatment failure with rising titres, nephrotic syndrome.
• Follow-up: repeat RPR or VDRL titre at 3, 6 and 12 months (24 months in HIV); a fourfold fall within 6 to 12 months shows cure; fourfold rise or persistent symptoms means retreatment and CSF examination.