Severe intractable common warts associated with human papillomavirus 2, 3 and 20.

A 26-year-old male had had numerous common warts on the feet and hands since childhood. They had repeatedly undergone etretinate cryosurgery, always responding well to it. However, the warts reappeared. Human papillomavirus (HPV) 2, 3 and 20 were detected in the warts using Southern's blot hybridization technique with HPV DNA. Histologically, the warts showed swollen, clear keratinocytes with vacuolated degeneration not found in common warts. The findings are presented in this paper.