Management of ungual warts.

Warts are the most common nail tumor generally caused by human papilloma virus (HPV) 1, 2, 4, 27, and 57. HPV 16 and 18 are associated with malignant transformation to squamous cell carcinoma, while HPV 2 and 7 are associated with "butcher's warts." Current treatments range from topical and intralesional therapies to systemic agents and surgical procedures. Despite the numerous available possibilities for treatment, intralesional bleomycin appears to be the most effective treatment for periungual warts.