Pustular secondary syphilis: report of three cases and review of the literature

BACKGROUND: Pustular syphilis is an extremely rare manifestation of secondary syphilis. Failure to recognize the disease can have devastating consequences. METHODS: We present three patients with pustular syphilis as the primary manifestation of secondary syphilis. RESULTS: Patient 1 was initially diagnosed by Venereal Disease Research Laboratory (VDRL) test (titers 1 : 32) and confirmed by enzyme immunoassay (EIA) for Treponema pallidum. Patient 2 was screened for syphilis by VDRL (titers 1 : 64), yielding a positive result, and tested negative for HIV. Secondary syphilis was confirmed by EIA. In Patient 3, a diagnosis of secondary syphilis was established by VDRL (titers 1 : 128) and EIA. Treponema pallidum was detected by dark field microscopy in three patients. Testing for HIV infection was negative in all patients. CONCLUSIONS: Diagnosis in secondary syphilis remains challenging because of the diversity of clinical presentations. The most commonly observed cutaneous presentation is a generalized, non-pruritic, papulosquamous eruption varying from pink to violaceous to brown, with mucous membrane involvement. The diagnostic methods used to identify secondary syphilis are the same as those used to diagnose other stages of syphilitic infection. The persistence of syphilis in both developed and underdeveloped regions highlights the importance of considering syphilitic infection in the setting of a cutaneous pustular eruption, especially one that fails to respond to standard therapy. Testing for other sexually transmitted diseases, including HIV, should be performed in all patients diagnosed with syphilis.