This 16 yr old boy had a 2 year history of a recalcitrant ulcerated plaque on his arm and recently developed a second lesion more proximally. His arm lesion was being treated with mycophenolate mofetil and prednisone. Interestingly, this patient also had acne fulminans and a history of aseptic arthritis, which along with pyoderma gangrenosum, is known as PAPA syndrome (pyogenic sterile arthritis, pyoderma gangrenosum, and acne). Several other members oh his family were similarly affected. Wise CA el al identified a mutation in the CD2 binding protein in this family and another family in the US. They proposed that this defect interferes with physiologic signaling necessary for maintaining a normal inflammatory response. (Hum Mol Genet 2002;15:961-9)
