WHAT IS MASTOCYTIC ENTEROCOLITIS?
Mastocytic enterocolitis (entero=small intestine, colitis- colon + -itis= inflammation) is a relatively new term for a subset of irritable bowel syndrome condition where there are discovered to be increased mast cells in the intestine. Mast cells are a type of immune cell. They are present in low levels in everyone’s intestinal lining as well in lots of tissues of the body in particularly in the skin, eyes and respiratory tract where they are involved in allergy reactions. They are present in tissues of the body for fighting infections, would healing and are also involved nerve signal regulation. They have numerous granules containing a variety of chemicals that mediate body reactions i.e. chemical mediators. Histamine is one of the main chemical mediators in mast cells that are released when mast cells are triggered. Mast cells present in the superficial intestinal lining or mucosa in small numbers except when there are exposures to parasites or other infectious agents, food allergies, increased stress or the presence of other chronic inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis. When mast cells release histamine and other chemicals, this irritates or inflames the bowel making it more permeable or leaky. This can set up a vicious cycle of pain and further gut injury.
WHAT ARE THE SYMPTOMS?
The most common symptoms of excess mast cells in the intestine are diarrhea, bloating and abdominal pain. However, constipation may occur due to gut paralysis. Nausea, vomiting and various non-GI symptoms such as flushing, headaches, and fatigue may also commonly occur. When histamine is released, it can cause increased gut permeability or leaky gut, increased contractions of the gut or decreased contractions, increased secretions and increased pain.
HOW IS IT DIAGNOSED?
When you have an endoscopic procedure the doctor may take samples of tissue (biopsies) from the lining of your intestines. The tissue is then sent to a pathologist who looks at it under the microscope. Mast cells may be hard to see on biopsies without a special stain for tryptase, an enzyme present in mast cells. Mastocytic enterocolitis is diagnosed when excess mast cells are present in the small bowel or the colon. A special request is usually needed for mast cell stains to be done on biopsies and most physicians do not order these special stains thereby missing the diagnosis.
HOW IS IT TREATED?
There are medications that can reduce the effect or block the release of the chemicals by the mast cells. The most common are antihistamines, both type I and type antihistamines. Type I antihistamines are typically used for allergies symptoms such as Zyrtec, Allegra, Claritin etc. The type II antihistamines are also acid blockers such as Zantac, Tagamet and Pepcid. These antihistamines compete with the histamine on the receptor of cells reducing symptoms. The most specific therapy for mastocytic enterocolitis is one of two medications that stabilize mast cells. The first is known as cromolyn sodium, available commercially in a liquid form for oral use under the brand name Gastrocrom. It is also available in other forms including an over the counter eye drop for eye allergies. It is typically prescribed four times a day for about 4-6 months. The other oral drug requires formulation by a compounding pharmacy. It is ketotifen. It is typically given as a dose of 1-2 mg orally twice daily for 4-6 months. Along with medication, you may benefit from having allergy testing done for the most common allergies, work on reducing or coping better with stress and consider taking a probiotic supplement.
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