Background: Warts occur commonly in humans. Destructive modalities are generally the first physician-administered therapy. Other treatment options include immunotherapy. Intralesional immunotherapy using mumps, Candida, or Trichophyton skin test antigens has proved efficacy in the treatment of warts.
Objectives: To determine rates of wart resolution in response to injection of antigen alone, antigen plus interferon alfa-2b, interferon alfa-2b alone, and normal saline; and to compare response according to viral type, major histocompatibility complex antigens, and peripheral blood mononuclear cell proliferation to autologous human papillomavirus antigen before and after injection.
Design: Randomized, single-blinded, placebo-controlled, clinical trial.
Setting: Medical school-based dermatology department.
Patients: Two hundred thirty-three patients clinically diagnosed as having 1 or more warts. Main Outcome Measure Clinical resolution of warts in response to intralesional immunotherapy.
Results: Responders were observed in all treatment arms, but were significantly more likely to have received antigen (P<.001). Resolution of distant untreated warts was observed, and was significantly more likely in subjects receiving antigen (P<.001). Interferon did not significantly enhance the response rate (P = .20) and did not differ from normal saline (P = .65). No viral type or major histocompatibility complex antigen correlated with response or lack of response (P>.99 and P = .86, respectively). A positive peripheral blood mononuclear cell proliferation assay result (2 times pretreatment levels) was significantly more likely among responders (P = .002). While there was no significant difference in response based on sex (P = .56), older subjects (>40 years) were less likely to respond (P = .01).
Conclusions: Intralesional immunotherapy using injection of Candida, mumps, or Trichophyton skin test antigens is an effective treatment for warts, as indicated by significantly higher response rates and distant response rates in subjects receiving antigen. Viral type and major histocompatibility complex antigens did not seem to influence treatment response. Response is accompanied by proliferation of peripheral blood mononuclear cells to human papillomavirus antigens, suggesting that a human papillomavirus-directed cell-mediated immune response plays a role in wart resolution.