Biologic False-Positive FTA-ABS Test in Drug-Induced Lupus Erythematosus

Procainamide hydrochloride-induced lupus syndrome was associated with development of false-positive serologic tests for syphilis. The unique feature of our case was the finding of a positive fluorescent treponemal antibody-absorption (FTA-ABS) test which became nonreactive following cessation of drug therapy. A previous association of this phenomenon with systemic lupus erythematosus has been noted. Therefore, one must interpret serologic tests for syphilis within the framework of clinical findings in both systemic and drug-induced lupus erythematosus.