Retrobulbar neuritis complicating acute Epstein-Barr virus infection.

A 19-year-old man presented with retrobulbar neuritis and was initially suspected to have neurosyphilis because of a positive microhemagglutination assay for Treponema pallidum (MHA-TP). However, a Venereal Disease Research Laboratory assay was negative, and the patient was subsequently diagnosed with infection due to Epstein-Barr virus (EBV) by heterophile antibody assay and serology for EBV. A biological false-positive MHA-TP has been reported in association with EBV infection. Physicians need to be aware that both retrobulbar neuritis and a biological false-positive MHA-TP can be seen in association with EBV infection.