Chinese dragon sign of ulcerative colitis.

We present a case of a 17-year-old woman with ulcerative colitis (UC) presented with abdominal pain and hematochezia. A CT scan showed active bowel inflammation, presenting the Chinese dragon sign. A diagnosis of exacerbation of UC was made. This sign refers to tortuous thick-walled sigmoid colon and rectum with narrow lumen resembles the body of the dragon and hypervascularity of the involved mesenteric vessels as bright dots next to the outer wall resemble the legs and skin spikes. Although this sign is nonspecific and may appear in ischemic colitis, ischemic colitis usually does not have rectal involvement and can be differentiated from typical UC.