Rare Causes of Abdominal Pain

Gastroenterologists commonly evaluate unexplained chronic or recurrent abdominal pain. In a review of overlooked causes of recurrent abdominal pain, some key points were:

• Chronic abdominal wall pain can occur in any quadrant but is most often located in the right upper quadrant and may or may not be associated with a scar. The best diagnostic techniques for chronic abdominal wall pain continue to be Carnett’s sign, the pinch test, and trigger point injection. Of patients with this condition, 80% are women.
• Vascular disorders can cause recurrent or chronic abdominal pain. The article includes information about chronic mesenteric ischemia and superior mesenteric vein thrombosis. The authors also remind us of median arcuate ligament syndrome, which is best diagnosed with a computed tomography angiography performed with the patient in deep expiration.
• Allergic disorders may present with abdominal pain.

• IgE-mediated food allergies are most commonly associated with shellfish, tree nuts, and peanuts. Typically, there is diffuse, crampy abdominal pain, bloating, nausea, and loose stools that resolve within a day.
• Mast cell activation syndrome is non-IgE mediated, and the abdominal pain coexists with skin or other mast cell symptoms, such as throat scratching, chest tightness, or rhinitis. Typical triggers are gluten, processed foods containing dyes or chemicals, medications such as antibiotics, and strong smells.
• Hereditary angioedema can produce sudden-onset crampy, diffuse abdominal pain without other associated allergic symptoms or exposure.

• Acute hepatic porphyria is another rare cause of abdominal pain, which is the most common symptom in patients with this genetic disease.