A Case of Pseudo-Pancolitis Due to Hereditary Angioedema

Abstract

Purpose: A 28-year-old female presented to the emergency department with the acute onset of right-sided abdominal discomfort. Laboratory evaluation was significant for a leukocytosis (15.3) and elevated c-reactive protein (43 mg/L). An abdominal CT scan demonstrated thickening of the terminal ileum, cecum and ascending colon, suggestive of colitis. Fecal leukocytes and stool cultures (including PCR for C. difficile) were negative. A colonoscopy, including terminal ileal exam, with biopsies was normal. Her pain improved with hydration alone. Three weeks later, she returned to the ER with 5 days of epigastric pain and watery diarrhea, with 10 stools per day. Labs again demonstrated a leukocytosis (17.4). Repeat CT scan of the abdomen revealed pancolonic thickening (Figure 1 & 2). C. difficile PCR, fecal leukocytes and stool cultures were again all negative. Given the concern for inflammatory bowel disease, a colonoscopy was repeated and revealed nonspecific edema in the transverse colon, otherwise normal. Because of her recurrent episodes of abdominal pain and colonic thickening of unclear etiology, testing for Hereditary Angioedema (HAE) was undertaken. Her complement C4 level was markedly reduced, and a diminished C1 esterase inhibitor activity confirmed the diagnosis. In nearly 25% of patients with HAE, gastrointestinal complaints are the presenting features. These patients often exhibit abdominal pain, nausea, vomiting and diarrhea, which are thought to be secondary to bowel wall edema. As of 2005, the mean elapsed time between onset of symptoms and diagnosis was greater than 10 years, underscoring the importance of considering the diagnosis of HAE in patients with recurrent abdominal complaints.FigureFigure