Published online Jul 12, 2015. doi: 10.5499/wjr.v5.i2.101
Peer-review started: November 26, 2014
First decision: January 20, 2015
Revised: March 13, 2015
Accepted: April 27, 2015
Article in press: April 29, 2015
Published online: July 12, 2015
Core tip: Pyoderma gangrenosum (PG) is occasionally seen in patients with systemic diseases such as rheumatoid arthritis (RA), inflammatory bowel disease, hematologic malignancy, and Takayasu’s arteritis. PG is sometimes precipitated by minor trauma or triggered by surgical operation or even by iatrogenic procedures such as needle prick or catheter insertion, which play a role as pathergy. Clinical appearances of ulcerative pyoderma gangrenosum mimic rheumatoid vasculitis or leg ulcers caused by impaired circulation in patients with RA. It is necessary for rheumatologists as well to understand pyoderma gangrenosum.