Periungual Keratoacanthoma Preceded by a Wart and Followed by a Verrucous Carcinoma at the Same Site

Sir, Periungual keratoacanthoma can be difficult to diagnose clinically. Its presentation may differ markedly from that of keratoacanthoma found elsewhere on the skin. The same observation concerning presentation is made for squamous cell carcinoma (SCC) of the perionychium and skin. A further distinction from SCC at these sites is the presence of human papilloma virus (HPV) in periungual squamous cell carcinoma and its routine absence at most other sites. We report the presence of oncogenic HPV 31 and 35 in a periungual keratoacanthoma, marked by the manifestation of a wart prior to and a verrucous carcinoma after the presentation of the keratoacanthoma at the same site.