An Antibacterial for a Viral Infection?

In his Photo Essay case of a 5-year-old girl with a herpes simplex virus (HSV) infection on her thumb (Figure), Dr Robert Blereau writes that treatment consisted of mupirocin ointment (CONSULTANT,  March 2005, page 360). Frankly, I was surprised to read that this agent was used to treat an HSV infection. Was this the only treatment? — Richard Rather, PA-C Brookfield, Wis Mupirocin ointment was the only treatment. I, too, did not appreciate the effectiveness of mupirocin for the treatment of HSV infection until about 15 years ago. Around that time, Walter B. Shelley, MD, and E. Dorinda Shelley, MD, authored a regular feature titled, “A Dermatologic Diary: Portrait of a Practice” in the dermatology journal Cutis. They presented an interesting case, along with a discussion of diagnosis and treatment, for virtually every day of the month. I saved on file cards a number of the treatment recommendations from the feature. The one I drew on for this case reads: “For the topical treatment of herpes simplex, we routinely prescribe mupirocin ointment. It is superior to acyclovir ointment in our experience.”1 I have used mupirocin to treat HSV infections ever since I came across this recommendation, and I have been pleased with the results. This antibacterial seems to have some antiviral activity, although I do not know the mechanism of action. — Robert P. Blereau, MD Morgan City, La REFERENCE: 1. Shelley WB, Shelley ED. A dermatologic diary: portrait of a practice. Cutis. 1991;48:21-26.