Intralesional bleomycin sulfate in treatment of recalcitrant warts

There has long been a pressing need for an effective, easy, and safe treatment for recalcitrant warts. Intralesional injection of bleomycin promises to meet these criteria most nearly. The bleomycins, a group of sulfur-containing polypeptide compounds, were isolated from Streptomyces verticillus, a Japanese soil fungus, by Umezawa 1 in 1962. They have both antibiotic and cytotoxic properties. The cytotoxic effect depends on the ability to cause DNA strand scission, especially in dividing cells entering the mitotic phase. 2 It affects both DNA and protein synthesis as well as cell division. Bleomycin is a broad-spectrum antibiotic with a variable antibacterial activity. Umezawa 3 demonstrated that bleomycin also inactivated SV40 by scission of both strands of its DNA. It is possible, therefore, that it could act directly on human papillomavirus (HPV) in the same way.