Spirochetal Diseases and Seventh Nerve Palsy

Abstract

Abstract Treponema pallidum and Borrelia burgdorferi may lead to seventh nerve palsy and should be suspected in the appropriate clinical context. Serologic testing for syphilis and Lyme disease (LD) is valuable but may show cross-reactivity. We describe a 20-year-old woman with left seventh nerve palsy secondary to latent syphilis of unknown duration, with complete recovery after penicillin G benzathine. In addition to reactive rapid plasma reagin and positive T. pallidum particle agglutination testing, Lyme enzyme-linked immunosorbent assay was equivocal, and Lyme Western blot was positive for immunoglobulin M. In syphilis, Lyme enzyme-linked immunosorbent assay may be falsely positive, but Western blot is known to remain negative. Similarly, in LD, fluorescent treponemal antibody absorption testing may be falsely positive, but rapid plasma reagin remains nonreactive. Careful interpretation of these serologic tests is of utmost importance in differentiating between the 2, especially in areas with low prevalence of LD.