Detection of HPV-15 in painful subungual tumors of incontinentia pigmenti: successful topical therapy with retinoic acid.

Incontinentia pigmenti (IP) is an X-linked dominant disorder, which occurs in female patients. We present a typical case of IP with subungual tumors (STIP) together with a short review on subungual tumors in IP. The diagnosis was achieved on the basis of the onset in adult life of STIP together with the other specific symptoms like ocular and dental abnormalities and achromic lesions of the legs. In the STIP lesions the presence and, in one of them, the expression, of HPV type 15 were detected. Topical therapy with retinoic acid cured the tumoral lesions. To the best of our knowledge this is the first report of HPV in STIP, opening a new scenario in the pathogenesis and the treatment of STIP. In conclusion, in our opinion, all painful subungual tumors should be considered as a possible late manifestation of IP.