Making the Diagnosis
To accurately assess and diagnose this patient’s condition, the clinician needs to consider conditions that would cause the abnormal findings on the CT scan, which include thickening of the intestinal walls (other cuts of the CT show mild thickening of the gastric walls and ascites around the spleen) as well as the presenting signs and symptoms.
Clinically, recurrent upper abdominal pain and vomiting in a young man will most likely be due to gastritis, pancreatitis, or cannabinoid hyperemesis. However, since the patient has no risk factors for these conditions, ordering a CT makes sense. The CT cut shows severe thickening of the intestinal walls, primarily on the left side of the image. No sign of gastrointestinal obstruction is found. The findings, therefore, are most consistent with a zebra: intestinal angioedema.
Intestinal angioedema (IA) is a rare cause of abdominal pain that typically presents with recurrent attacks of diffuse abdominal pain often with vomiting and/or diarrhea but without fever. Although pain is typically diffuse, it can occasionally be more focal, as in this case presented. Of interest, IA is not known to occur with acquired forms of angioedema such as those secondary to the use of angiotensin-converting enzyme (ACE) inhibitors or other medications. It only occurs with hereditary angioedema (HAE).
A laboratory workup is typically unrevealing for IA, although white blood cell count and inflammatory markers can be elevated. When suspicion is high, tests such as serum tryptase and urine histamine can be useful for follow-up but are not typically ordered by the ED provider. The diagnostic study of choice is CT and scans will show thickening of the intestinal and/or gastric walls with or without secondary dilation or even partial obstruction. Occasionally, ascites can be seen on CT — as was seen on other CT cuts around the spleen, which interestingly was where the pain localized.
Treatment is typically supportive with analgesics, antiemetics, and bowel rest. Antihistamines or steroids are often used but are unproven. Hereditary angioedema-specific medications can be used in the few medical centers that stock them or if a patient with HAE has been prescribed them.
The patient was admitted to the hospital and given intravenous fluids, NSAIDs, and observation.
Brady Pregerson, MD, is an emergency physician at Tri-City Medical Center, Palomar Health System, and Scripps Coastal Urgent Care, all in San Diego, California.
Pregerson DB. GI chapter. Emergency Medicine 1-Minute Consult. 5th ed. 2017;5. http://www.erpocketbooks.com/emergency_medicine_reference_books/quick-essentials-emergency-medicine/