A 25-year-old male student presents with the chief complaint of rash. He denies headache, fever, or myalgia. A slightly pruritic maculopapular rash is noted over the abdomen, trunk, palms of the hands, and soles of the feet. Inguinal, occipital, and cervical lymphadenopathy is also noted. Hypertrophic, flat, wart-like lesions are noted around the anal area. Laboratory studies show the following:Hct: 40%Hgb: 14 g/dLWBC: 13,000/mLDiff: 50% segmented neutrophils, 50% lymphocytesWhich of the following is the most useful laboratory test in this patient?

Diffuse rash involving palms and soles should suggest the possibility of secondary syphilis. The hypertrophic, wart-like lesions around the anal area, called condyloma lata, are specific for secondary syphilis. The VDRL slide test will be positive in all patients with secondary syphilis. Rash and lymphadenopathy would not be found if the perianal lesions were due to HPV Chlamydia infections cause urethritis with mucopurulent discharge from the penile meatus but not the rash or hypertrophic skin changes. Blood cultures might be drawn to rule out bacterial infection such as chronic meningococcemia; however, the clinical picture is not consistent with a systemic bacterial infection. Biopsy of the condyloma is not necessary in this setting, as regression of the lesion with treatment will distinguish it from genital wart (condyloma acuminatum) or squamous cell carcinoma. Penicillin continues to be the drug of choice for all stages of syphilis.