Symptomatic relapse of neurologic syphilis after benzathine penicillin G therapy for primary or secondary syphilis in HIV-infected patients.

We describe 3 symptomatic cases of neurologic syphilis that occurred after the administration of the usual therapy for primary or secondary syphilis in human immunodeficiency virus (HIV)-infected patients. We discuss the difficulty of diagnosing neurosyphilis, the need for lumbar puncture, and risk factors of relapse. Because HIV infection may alter the natural history and response of neurologic syphilis to treatment, scrupulous follow-up and repeated cycles of therapy are warranted.