Allergy & immunology · Cincinnati
Mast cell activation and unexplained bowel symptoms
Flushing, hives, cramping, bloating and diarrhea that come and go, often with no clear cause, can be signs of a mast cell disorder. Dr. David I. Bernstein evaluates and treats patients with mast cell activation, including those whose main symptoms are in the gut.
What mast cell activation is
Mast cells are immune cells in the skin, gut, airways and blood vessels. When they release chemical signals such as histamine too easily or too often, they can cause symptoms in several parts of the body at once. This is called mast cell activation.
Symptoms usually come in episodes and involve two or more organ systems, for example skin flushing with abdominal cramping, or hives with lightheadedness. Many patients have seen several specialists before mast cells are considered.
Mast cell symptoms are often reported alongside other conditions, including hypermobility (Ehlers-Danlos syndrome), POTS and other forms of dysautonomia.
Common symptoms
- Bloating, abdominal cramping, nausea or diarrhea
- Flushing, itching or hives
- Lightheadedness or a racing heart
- Nasal congestion, wheezing or throat tightness
- Episodes set off by heat, stress, exercise, alcohol, certain foods or medicines
How it is evaluated
There is no single test. Diagnosis relies on the pattern of symptoms, laboratory evidence of mast cell activity and response to treatment.
Detailed history
Which organ systems are involved, what triggers episodes and which treatments have helped.
Blood and urine tests
Measuring tryptase and other mast cell mediators, ideally during and after an episode, compared with a baseline level.
Ruling out look-alikes
Considering allergies, gastrointestinal disease, mastocytosis and hereditary alpha-tryptasemia, in coordination with your other physicians.
Treatment trial
Seeing whether symptoms improve with medicines that block or calm mast cells.
How it is treated
Treatment is tailored to the symptoms and is usually stepwise. Common options include long-acting antihistamines that block both H1 and H2 receptors, cromolyn sodium taken by mouth for gut symptoms, leukotriene blockers and, for some patients, biologic therapy.
Identifying and avoiding personal triggers is part of every plan. Patients who have had severe episodes are given an emergency plan and epinephrine.
A visit may help if
- Bowel symptoms persist despite a normal gastrointestinal workup
- Flushing or hives come with gut or heart-rate symptoms
- You react to many foods, medicines or smells without a clear allergy
- You have hypermobility or POTS with episodic allergic-type symptoms
Common questions
Can mast cells cause bloating and diarrhea?
Yes. The gut contains many mast cells, and chemicals they release can cause cramping, bloating, nausea and diarrhea, often alongside skin or other symptoms.
Is mast cell activation the same as an allergy?
Not exactly. Allergies involve a specific trigger and an allergic antibody. In mast cell activation, mast cells release chemicals more easily, sometimes with several triggers or none that can be identified.
How is it different from mastocytosis?
Mastocytosis means there are too many mast cells, usually confirmed with a bone marrow or skin biopsy. Mast cell activation can occur with normal numbers of mast cells. Testing helps tell them apart.
What should I bring to a consultation?
A list of your symptoms and what seems to trigger them, any lab results including tryptase levels, gastrointestinal test results and the treatments you have tried.
Living with unexplained flushing, hives or bowel symptoms?
Request a consultation. Dr. Bernstein reviews every request personally.