Complications of liquid nitrogen cryosurgery for verrucae over bony prominences

Liquid nitrogen cryosurgery is the most frequently used surgical treatment for verrucae. Its success rate is high and complications are rare. However, liquid nitrogen should be used with great care over bony prominences where skin and subcutaneous tissues are thin. We present 3 patients in whom the treatment of simple warts over bony prominences by liquid nitrogen resulted in full-thickness loss of skin. In 2 of them, extensor tendons of fingers were exposed and had to be covered with flaps. We conclude that expertise of the physician is of paramount importance in preventing similar complications in cryosurgery of verrucae.