The incidence of recurrent herpes simplex and herpes zoster infection during treatment with arsenic trioxide.

We report the incidence of varicella zoster virus (VZV) and herpes simplex virus (HSV) infection in patients with multiple myeloma and colon cancer who were treated with arsenic trioxide for their disease. In this report, we discuss the effects of arsenic on immune system, and suggest arsenic compounds as a possible predisposing factor for viral reactivation in these patients.