Angioedema is local and temporary swelling usually affecting skin layers but sometimes it may also afflict hollow viscera such as oropharynx, bronchi, or the bowels. Intestinal angioedema is a rare condition characterized by swelling of the walls of intestine. Both small as well as large intestine can be affected.
Often this condition can become a diagnostic dilemma for the emergency physician because of its rarity and symptoms similarity with many other common gastrointestinal conditions. Patients usually complain of pain in abdomen, vomiting and diarrhea. Intestinal angioedema can be due to many reasons such as food allergy, medications, heredity etc.
Treatment is directed towards the type of angioedema. For example if it is caused due to drug, withdrawal of the drug will cure the illness.
Causes Of Intestinal Angioedema
Angioedema is the swelling of the deeper layer of skin, subcutaneous tissues underlying the skin or submucosal layer of hollow tissues and organs. The intestinal lining is made up of mucus and underneath it is the submucus layer. Angioedema of intestine occurs when the vessels of submucus layer starts to leak. This causes fluid to seep out from the blood into the interstitial fluid of the submucus layer.This causes swelling of the intestinal wall.
Majority cases of intestinal angioedema are related to drug, especially ACE (angiotensin converting enzyme) inhibitors which are used for treating hypertension. The enzyme ACE acts upon the vessel wall to contract. This leads to hypertension. ACE inhibitors block this contraction so that the vessel wall is much relaxed. ACE inhibitors also tend to cause excess of bradykinin and in turn try to dilate the vessel wall. This helps to lower the pressure of blood in the blood vessel. But bradykinin on the other hand increases permeability of blood vessel. This leads to leakage of fluid from the blood which enters into the interstitial space of the submucus layer of intestine, causing swelling or edema.
The other cause of intestinal angioedema is hereditary or acquired angioedema. It occurs due to deficiency of an enzyme called C1-INH. This enzyme prevents the action of C1 an immune substance. When there is deficiency of C1-INH, C1 has freedom to act. It increases the level of kinins and thus makes the vessel wall more permeable and leaky. It thus can cause intestinal angioedema.
Rarely intestinal angioedema can occur due to food allergy or any other types of allergies.
Signs And Symptoms Of Intestinal Angioedema
The symptoms of intestinal angioedema are not peculiar to the disease. They are common in many intestinal disorders. Physicians therefore get confused of the condition. Frequently detailed medical history, clinical examination, helps to conclude intestinal angioedema. The most prominent symptoms are:
- Pain in abdomen which may increase in its intensity after eating food.
- Sudden spasmodic cramps in intestine.
- Nausea and vomiting.
- Distension of abdomen may occur in some patients. Usually it may be mistaken as intestinal bloating due to excess of gas.
The other associated symptoms include loss of appetite, weight reduction if patient is not able to eat food properly for a prolonged period of time. Nutritional deficiencies, malabsorption syndrome etc are common with this condition. The acute symptoms may remain for a short period of time and resolve. But it can recur often due to the exposure to the offending agent, for example ACE inhibitor drug.
Intestinal angioedema may not be a solitary condition as in most cases it may be accompanied with urticaria on skin, swelling of lips and throat etc.
Diagnosis And Treatment For Intestinal Angioedema
Intestinal angioedema can be detected with the help of imaging techniques such as CT scan and MRI. Both can identify the narrowing of lumen of the intestine. The other procedure used frequently is barium swallow. Apart from the investigative procedures, good medical history, accompanied symptoms and frequent episodes of hives will help the physician to diagnose intestinal angioedema quickly. For hereditary cause, a blood test of C1-INH is useful.
Usually without any interventional measures, the typical symptoms of intestinal angioedema last for 1 to 3 days. This may depend on the underlying cause. However, treatment is necessary to relieve pain. Management is focused on addressing the underlying cause. For example, discontinuing the drug (ACE inhibitor) will help to cure the condition. In hereditary type certain inhibitor such as bradykinin and kallikrein inhibitors will be useful. Use of anabolic steroids is also beneficial.