Non-specific positive test results to syphilis in dermatological diseases.

Sera from 3028 patients attending a dermatological clinic were examined by the fluorescent treponemal antibody (FTA) test, the fluorescent antibody-absorbed (FTA-ABS) test, the Venereal Disease Research Laboratory (VDRL) test, and Kolmer's test. Eleven cases of late syphilis were found. Sera from 63 (2.08%) of the remaining 3017 patients showed non-specific results; these were found more frequently in patients with pyodermas, neoplasms, acne, mycoses, crural ulceration, and psoriasis than in those with other diseases. No non-specific results were observed in patients with bullous skin diseases and only a few in patients with viral skin diseases and chronic lupus erythematosus. The test producing the most non-specific results was the FTA test, followed by the FTA-ABS test, the VDRL test, and Kolmer's test.