top of page

Mast Cell Activation Syndrome & Mastocytosis- What Every Medical Professional Should Know

Updated: Apr 27, 2023

Patients with hypermobile Ehlers-Danlos Syndrome (hEDS) may frequently present with Mast Cell Activation Syndrome (MCAS) or Mastocytosis, which can make the management of these cases quite complex as symptoms overlap and may even resemble symptoms of Postural Orthostatic Tachycardia Syndrome (POTS), also commonly seem on EDS patients. The understanding on how this diagnosis can affect each patient is of extreme importance as there are over 200 mediators which can be released from mast cells; which can affect various processes within the body.

What is Mast Cell Activation Syndrome?

Mast cells are allergy cells which are part of the immune system and are responsible for immediate allergic reactions. When an allergy antibody IgE is present on the surfaces of the mast cells, mediators are released causing an allergic reaction. When the activation of mast cells is triggered by external stimuli such as medications, infections, insects or any other external causes this is known as secondary activation.

Mast cells can also become "defective" and release responses due to abnormal internal signals even when no external stimulus or allergen has entered the body. Some mast cells may undergo mutations in their original make up (clone cells - cells that are identical to mast cells) to overproduce and spontaneously release mediators which bring on allergic reactions. This type of releasing is known as primary activation. These clones can continue to misfire and are more sensitive to activation, which is known as mastocytosis.

MCAS is a condition in which the person affected experiences multiple episodes of the symptoms of an anaphylaxis reaction. Symptoms would include hives, swelling, low blood pressure, difficulty breathing and diarrhea. The cause is unknown and there is no allergen or secondary response that would cause normal mast cells to activate and release mediators.

Causes of Mast Cell Activation Syndrome

Scientists are still uncertain of the cause; however, it has been linked to preterm labor, fertility issues, allergic rhinitis, interstitial cystitis, miscarriage, chronic pain, preeclampsia, anxiety/depression, IBD, food intolerances and hyperemesis during pregnancy. Treatment of MCAS has been successful with mast cell-stabilizing or mediator-targeting drugs. MCAS is often misdiagnosed, or patients are left confused as no diagnosis is concluded or can be misdiagnosed as allergies. This is as MCAS involves multiple organ systems and there is little commercial testing available.

Mast cell activation syndrome symptoms can be significantly different from person to person, and symptoms may often replicate allergy, food poisoning, cold or other infectious diseases symptoms. Because symptoms often occur in relation to food consumption, hence why it can often be misdiagnosed as an allergy. However, episodes without a specific cause may occur in the absence of food consumption.

Some symptoms which have been recognized may include but are not limited to:

  • Inflammation

  • Generalized pain

  • Swelling

  • Disorders of the nervous systems e.g. sleep disturbance, nervousness, and depressive moods

  • Chronic or acute irritation

  • Diarrhea or constipation

  • Flatulence

  • Abdominal bloating

  • Chronic inflammatory disease

  • Hives, itching and skin rash etc.

  • Cardiac arrhythmias

  • Nausea and vomiting

  • Headaches

Symptoms of MCAS are like that of anaphylaxis such as:

  • Rapid heart rate

  • Low blood pressure

  • Passing out

  • Itching

  • Hives

  • Swelling

  • Flushing of the skin

  • Wheezing

  • Breathlessness

  • Harsh noises when breathing due to throat swelling

  • Diarrhea

  • Nausea

  • Abdominal pain

Symptoms Management

Once a diagnosis has been reached it is time to begin to work to manage the condition. MCAS can be managed by removing triggers that cause episodes. Eliminating/limiting foods that are high in natural chemicals such as histamines, amines, salicylates, glutamate, and preservatives/additives has been shown to help manage symptoms of MCAS, but necessarily are the exact solution for some patients.

There are over 200 mediators which can be released from mast cells, which can affect various processes within the body. Histamine has been found to be a trigger to multiple bodily functions. If histamine or other trigger food chemicals are consumed and mediators are released regularly this can cause bodily processes to be disrupted. As mast cells can migrate to different parts of your body, depending on which part of the body the mast cells are activated will depend on which tissues, organs or organ systems will be affected.

Common symptoms experienced are:

  • Hives/urticaria/swelling/itching

  • Gastrointestinal discomfort: bloating, flatulence, diarrhea, nausea, constipation

  • Respiratory type symptoms such as breathlessness, wheezing, asthma

  • Neurological symptoms such as anxiety, depression, brain fog, fatigue, irritability, difficulty sleeping

  • Flare ups of other inflammatory conditions such as interstitial cystitis, colitis, diverticulitis, arthritis, psoriasis etc.

  • Fertility issues, menstrual irregularity, severe cramping and abdominal pain, pre-menstrual dysphoric disorder

  • Exercise intolerance

  • Cardiovascular symptoms like dizziness, low blood pressure, near syncope (fainting), tachycardia (fast heart rate), palpitations

Some foods that are common to trigger symptoms can include red wine, sparkling wine, fish especially tuna, seafood, meat, tomatoes, bananas, spicy foods, nuts, chocolate, fermented dairy like cheeses and yogurts, convenience foods and preservatives/additives to name a few. Once the first stage is completed, test foods containing the various food chemicals in different quantities are reintroduced carefully, to work out how many different foods you can tolerate without triggering your symptoms.

The foods that did cause symptoms are reintroduced slowly to find the amount of the food you can eat without causing symptoms. This step is important as it allows the person to enjoy a variety of foods and avoid cutting food groups out completely as it helps to establish the limit tolerated.

In general, it’s quite a restrictive diet and there is a risk of nutritional deficiency with prolonged use and so the liberalization step is very important and should be performed under guidance of a professional with extensive experience on this diagnosis and who can provide advice on supplementation if necessary.

Next week I will be discussing exercises and physical activity for patients with MCAD, stay tuned.

Photo credit: © <a href=''>thecorgi</a>, <a href=''>123RF Free Images</a>


bottom of page