Intralesional injection of mumps or Candida skin test antigens: a novel immunotherapy for warts.

BACKGROUND Warts are common and induce physical and emotional discomfort. Numerous therapies exist, yet none is optimal. Despite theoretical advantages, immunotherapeutic modalities are often neglected as first-line wart therapies. OBJECTIVE To compare treatment with intralesional skin test antigen injection of 1 wart vs cryotherapy of all warts. DESIGN Pilot study. SETTING University dermatology outpatient clinic. PATIENTS A total of 115 consecutive patients with at least 1 nongenital wart. INTERVENTIONS Patients with warts were tested for immunity to mumps and Candida using commercial antigens. Nonresponders received cryotherapy and immune individuals received cryotherapy or intralesional injection of 1 antiserum. RESULTS Thirty-four (30%) of the 115 patients did not respond to the test injections and 81 (70%) had detectable immunity. Of the immune group, 26 (32%) received cryotherapy, 45 (56%) received intralesional mumps antiserum, and 10 (12%) received intralesional Candida antiserum. Of the anergic patients, 28 (82%) were treated with cryotherapy; 6 (18%) refused cryotherapy. Of the 39 patients who were treated with immunotherapy and completed the protocol, 29 (74%) had complete clearing of the treated wart. Fourteen (78%) of 18 patients with complete resolution of their immunotherapy-treated wart also had resolution of untreated, distant warts. CONCLUSIONS Intralesional injection of mumps or Candida antigens into warts of immune individuals represents effective treatment. Observation of clearing of anatomically distinct and distant warts suggests acquisition of human papillomavirus-directed immunity in some patients. We conclude that this novel approach to immunotherapy may serve as first-line treatment in immune individuals with multiple or large warts and as second-line treatment in immune patients for whom cryotherapy fails.