Successful oral acyclovir desensitization

A 65-year-old woman with the acquired immunodeficiency syndrome (AIDS) complicated by recurrent mucocutaneous herpes simplex virus (HSV) infection developed angioedema on the initiation of her second course of oral acyclovir therapy. Oral rechallenge in hospital three days later confirmed acyclovir hypersensitivity. Vidarabine and foscarnet therapies were abandoned after treatment failure and unacceptable toxicity. Acyclovir desensitization was accomplished using a protocol derived from oral penicillin desensitization regimens. Mucocutaneous HSV infection responded to intravenous acyclovir followed by chronic oral suppression without recurrences of HSV or hypersensitivity. This report is an example of acyclovir hypersensitivity and successful oral desensitization.