A 25-year-old male presents with C/O rash. There is no fever or myalgia. A slightly pruritic maculopapular rash is noted over the abdomen, trunk, palms of the hands and soles of the feet. Lymphadenopathy is also noted. Hyperophic, flat, walike lesions are noted around the anal area. Lab studies show: PCV: 40% HB: 14 g/dL WBC: 13,000/ml DLC: N50, L50 The most useful laboratory test in this patient is

The diffuse rash involving palms and soles would in itself suggest the possibility of secondary syphilis. The hyperophic, walike lesions around the anal area, called condylomata lata, are specific for secondary syphilis. The VDRL slide test will be positive in all patients with secondary syphilis. The Weil-Felix titer has been used as a screening test for rickettsial infection. In this patient, who has condylomata and no systemic symptoms, Rocky Mountain spotted fever would be unlikely. No chlamydial infection would present in this way. 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. Penicillin is the drug of choice for secondary syphilis. Ceftriaxone and tetracycline are usually considered to be alternative therapies.