Bullous pyoderma gangrenosum of the bilateral dorsal hands.

Pyoderma gangrenosum (PG) shows characteristic non-infectious ulcers that are commonly associated with systemic diseases such as inflammatory bowel diseases, myeloproliferative disorders or aortitis syndrome. The typical clinical appearance is undermining ulcers with reddish and irregular borders on the legs. As PG has these notable signs, the diagnosis is relatively easy and its treatment depends on the severity of underlying complications.