The Diagnostic Dilemma of Otosyphilis: A New Western Blot Assay

Abstract

Currently, the diagnosis of otosyphilis applies to any patient with otologic symptoms of unknown cause and a positive fluorescent treponemal antibody-absorption (FTA-ABS) test result. However, the FTA-ABS assay can have false-positive results and does not distinguish between active and treated disease. The VDRL test, which has been used to distinguish inactive disease, frequently yields negative results in patients who are nonetheless given the diagnosis of otosyphilis. A new Western blot assay can eliminate the possibility of a false-positive result and can confirm whether the infection is active. This assay was used to diagnose unsuspected active syphilis in a patient believed to have autoimmune ear disease. In three other cases of suspected otosyphilis, the diagnosis was refuted when the Western blot demonstrated that the FTA-ABS result was false-positive or that the infection was inactive.