Using intralesional immunotherapy for treating warts has proven to be an effective therapy. This technique uses skin test antigens such as Trichophyton, Candida, and mumps to induce a systemic T-cell mediated response to the infection. However, the treatment response varies between studies. This may be due to differences in the antigens used, or other factors. Therefore, more randomized comparative studies are necessary to determine the proper standardized doses and schedules of antigen administration.

A clinical study published in Arch Dermatol looked at the efficacy of different antigens in patients with warts. In 160 subjects, each of which had at least one wart, the effects of injecting the different antigens was compared. During the study, each modality was injected into the largest wart at 2-week intervals until complete clearance of the infection. The study provided insight into the duration and frequency of injection and the doses of each antigen. In addition, the effect of interferon on the response rate was compared.

There were no differences between the response to saline and interferon in the overall population, but responders were significantly more likely to receive the antigen. In addition, the peripheral blood mononuclear cell proliferation assay was significantly more common among responders. In contrast, the local complications were not statistically significant.

The study evaluated a triple intralesional immunotherapy combination consisting of a purified protein derivative, a measles-mumps-rubella vaccine, and a tuberculin PPD antigen for its effectiveness. The purified protein derivative is a TLR7 agonist. It was chosen because of its positive intradermal sensitization test and the lack of a destructive approach. This treatment has proven to be safe and effective in treating recalcitrant warts. It has been shown to have a very low recurrence rate.

A randomized study of pediatric patients was performed. Children were assigned to three groups. The first group received five injections of the three modalities at four weeks, followed by another five injections of each modality at six weeks. The second group received the same modalities at six weeks but in a shorter treatment regimen. The third group received a less intensive vaccine regimen. The results of this study suggest that the treatment may be effective in warts in the pediatric population.

In another randomized trial, patients were divided into four treatment groups. Two of the treatment modalities did not clear warts in the children. The other two treatments were effective. These results suggest that intralesional approaches may be useful in patients with recalcitrant warts. The study concluded that the randomised study results are promising, but more randomized comparative studies are needed to determine the correct standardized doses and protocols of antigen administration.

A separate study evaluated immunotherapy for safety and effectiveness in pediatric patients. This study consisted of 40 children with multiple anogenital warts. The study results show that the combined treatment of the three modalities was more effective in clearing warts than the other two modalities. In fact, the combined treatment resulted in 100% clearance of warts by the end of the study. In addition, the local complications were not statistically significant, and the patients required a lower dose of the vaccine.