Got Warts? Try the MMR Vaccine Intralesional Immunotherapy of Plantar Warts: Report of a New Antigen Combination

Background: Think of all the different ways we treat warts and you have an overview of the stark fact that nothing works all that well. One common technique used especially in primary care is immunotherapy with Candida antigen. There have been literature reports of success also with mumps, Trichophyton, and tuberculin vaccines. Objective: To test the effectiveness of the use of measles/mumps/rubella (MMR) vaccine intralesional therapy for plantar warts. Design/Participants: Unblinded cased series of 40 patients with single or multiple plantar warts. Methods: The subjects were tested for existing immunity with 0.5 cc of intradermal injection of MMR vaccine. Wart dosing was based on the response to the test. The MMR vaccine was injected into single warts or the largest wart in case of multiple lesions at 3-week intervals until complete clearance occurred or for a maximum of 3 treatments. Follow-up was done every 3 months for a total of 9 months to detect any recurrence. Results: 23 patients completed the study; the other patients discontinued for a variety of reasons including nonreactivity to MMR vaccine, failure to follow-up, and side effects such as flu-like symptoms and pain of the procedure. Single lesions were present in 13 patients and multiple lesions were found in 10 patients. Eight patients had recalcitrant warts and 6 had warts distant from the plantar warts. The duration of the lesions ranged from 3 to 20 months with a mean of 7.4 months. Fourteen patients received previous treatment in the form of keratolytics, cryotherapy, or electrocautery. For those who completed the study, complete clearance of the warts occurred in 20 patients, with >50% clearing in 1 patient and <50% clearing in 2 patients. Complete response was achieved in 6 of 8 patients with recalcitrant plantar warts and in 5 of 6 patients with warts at sites other than the soles. Side effects included pain during injection and flu-like symptoms, which occurred in 1 patient. Conclusions: Intralesional immunotherapy by MMR vaccine seems to be a simple, effective, and safe treatment modality for plantar warts. Reviewer's Comments: This study reported higher response rates with fewer treatments than previous studies. The authors speculated that this might be because of the use of 3 viral antigens that might potentiate each other. The obvious problems with the study are an absence of a control population, small numbers, absence of blinding, and possibly lead bias. Still, this study presents some modest efficacy data and the therapy is significantly cheaper, safer, and easier than some other intralesional therapies including bleomycin. (Reviewer-David L. Swanson, MD).