Pathophysiology

1) infection with spirochete Treponema pallidum 2) hallmark is active disease periods (primary, secondary, tertiary) with latency 3) can also occur congenitally

Signs and Symptoms

Primary phase – 1) painless, single chancre on penis, mouth, anus, cervix, or labia for 4-6 weeks that spontaneously resoves 2) painless, nonsuppurative regional lymphadenopathy (can persist for months) Secondary phase – 3) skin rash that is maculopapular, bilateral, starts on trunk, and progresses to soles and palms 4) if rash coalesces and erodes, forms condylomata lata (10%) 5) mucous patches 6) alopecia areata 7) sore throat, fever, malaise 8) generalized painless lymphadenopathy Tertiary phase – 9) headache/sore neck/seizures 10) aortic dilation/aortic regurgitation 11) gradually progressive middle cerebral artery stroke 12) tabes dorsalis (wide-based gait, ataxia, paresthesias) 13) paresis (Argyll-Robertson pupil, decreased intellect, personality changes) 14) gummas Congenital type – 15) rhinitis (”snuffles”) 16) skin lesions (bullae, papulosquamous lesions, condyloma lata) 17) Clutton’s joints (bilateral knee effusions) 18) Hutchinson’s teeth (notched, peg-shaped molars)

Characteristic Test Findings

Laboratory – 1) greatly increased alkaline phosphatase 2) anemia 3) thrombocytopenia 4) leukocytosis 5) darkfield exam for organism ID 6) serum tests are nontreponemal RPR and VDRL slide test and treponemal FTA-ABS and MHA-TP

Histology/Gross Pathology

Tertiary phase – 1) endarteritis obliterans of vas vasorum 2) medial necrosis of aorta 3) gummas are granulomas with central area of necrosis 4) demyelination of posterior columns and dorsal roots

Associated Conditions

Primary phase – 1) HIV and other sexually transmitted diseases Secondary phase – 2) hepatitis 3) arthritis 4) iritis Tertiary phase – 5) bladder disturbances 6) impotence

Inheritance/Epidemiology

1) transmission via sexual contact, in utero, and blood transfusion 2) most common in USA in African Americans 3) incubation period is 20-30 days 4) 30% of untreated cases progress to tertiary form

Treatment

1) penicillin G for all phases 2) tetracycline in penicillin allergy 3) all sexual contacts (even if asymptomatic) should receive antibiotics

Tips for USMLE

1) best way to tell difference between syphilis, herpes, and chancroid – syphilis lesions and lymphadenopathy are painless 2) if question mentions uveitis and rash on soles and palms, consider syphilis 3) Argyll Robertson pupil is a small fixed pupil