Successful treatment of periungual warts with topical cidofovir

Periungual warts represent a treatment challenge because of its high recurrence rate and recalcitrance. These are benign lesions produced by the human papilloma virus (HPV) that often do not respond to habitual treatment. Cidofovir is a potent antiviral drug that acts inactivating viral DNA polymerase. Topical cidofovir for the treatment of HPV‐related cutaneous and mucous lesions is becoming increasingly common. Our aim was to assess the efficacy and safety of cidofovir cream for the treatment of viral periungual warts. We undertook a retrospective observational study of patients with periungual warts who received treatment with topical cidofovir between January 2010 and December 2013 at the Dermatology Service of the Hospital Costa del Sol, Marbella, Spain. Data were recorded about the rate of treatment response, the adverse effects and recurrences, as well as the characteristics of the patient cohort. We identified 41 patients who had received some previous treatment. The concentration of cidofovir was 3% in all cases, usually applied twice a day (in 37 of the 41 cases). A greater or lesser response was noted in 35 cases. There were six recurrences in the follow‐up period. Topical cidofovir seems to be a useful alternative for the therapeutic management of recalcitrant periungual common warts that fail to respond to usual treatment. Our experience with the use of this antiviral agent has been satisfactory, although in our opinion, it should be reserved for specific cases as its economical cost represents an important limitation.