Is Mast Cell Activation Syndrome a Hidden Epidemic?

Mindd Foundation

mast cell activation

Mast cells (allergy cells) are essential to the body. They are a type of white blood cell that can be found under the skin, lymph vessels, and in the nerves of the lungs and intestines. These cells are vital in strengthening the immune system due to their ability to respond to parasites, bacteria, and other immune system issues(1). Mast cell activation may induce allergic reactions that could affect the stomach, skin, and respiratory system. To manage these allergic reactions, individuals should avoid triggers and work with their Integrative practitioner to apply topical therapies.

Meanwhile, diagnostic methods used in determining these activations are much more complicated. Since the symptoms overlap with symptoms of other disorders, a number of criteria should be kept in mind.

What Is Mast Cell Activation Syndrome?

There are similar symptoms of chronic conditions that may be misinterpreted as an epidemic due to the widespread occurrence of infectious diseases. Thus, it is crucial to find the origin of these illnesses to diagnose them properly.

Mast cell activation syndrome (MCAS) is suspected to be heterogeneous and known for its clonality and being the underlying cause of various inflammatory diseases(2).

Mast cell activation syndrome is a collection of mast cell diseases characterized by repeated episodes of allergic symptoms, like difficulty breathing, swelling, severe diarrhea, hives, and low blood pressure.

MCAS may involve a broader group of mast activation disorders(3). This disorder occurs when mast cells are triggered and release mediators made by the cells or stored inside them.

Allergic reactions ensue when these mediators are released (degranulation) and bind with the protein of allergens(4).

Mast cell activation may involve the neurologic, cardiovascular, respiratory, and gastrointestinal systems, and the skin.


A study conducted in 2017 noted that among the 15,298 patients tested in an allergy clinic, 5.9% of them have a high tryptase level (an indicator of mast cell activation).

These patients with increased tryptase levels reported intense anaphylactic symptoms towards radiologic contrast media, drugs, and venom(5). They also experienced vertigo, diarrhea, fatigue, flushing, palpitations, and edema(6).

The same study stated that monoclonal mast cell activation syndrome (MMAS) is rare as it occurs in 1 in 10,000 to 20,000 subjects. Typical allergies, such as allergic asthma and allergic rhinitis, may affect 10% to 20% of the general population(7)



Mast cell activation may be triggered by various factors like(8):

  • Medications: antibiotics, intravenous, NSAIDs (nonsteroidal anti-inflammatory drugs), and opioids
  • Venoms: jellyfish, spider, or bee stings
  • Sudden temperature changes
  • Stress: fatigue and emotional stress
  • Environmental factors: food, pollen, dirt, and pollution
mast cell activation
mast cell activation


When a person experiences MCAS, the following symptoms may be observed(9):

  • Diarrhea
  • Vomiting
  • Bloating
  • Abdominal pain
  • Rashes
  • Cramps
  • Sweating
  • Brain fog
  • Fatigue

Some symptoms observed in people with MCAS are specific to the mediator of the mast cell. Below are some mast cell mediators and their possible symptoms(10):

  • Heparin: clotting or bleeding, osteoporosis
  • Tryptase: skin lesions
  • Prostaglandins: cramping, bone pain, and flushing
  • Histamine: hypotension, itching, and diarrhea


MCAS symptoms often overlap with other diseases. Thus, its diagnosis may be more difficult(11).

Nevertheless, three criteria are considered when diagnosing MCAS(12):

  1. Response to anti-mediator treatment
  2. Presence of usual symptoms
  3. Serum tryptase levels

These criteria assure that the diagnosis for the symptoms experienced is associated with mast cell activation. Therefore, it is vital to satisfy all of these three criteria before concluding the cause of the disease.

After checking for these criteria, the patient’s blood samples are collected and tested for mast cell growth receptor KIT (KIT D816V). This test indicates the presence or absence of clonal mast cell disorder(13)


Other Diseases Associated with Mast Cells

Mast cell disorders are rare. However, they may be severe. One type of mast cell disorder is the abnormal accumulation of mast cells in the body or mastocytosis. This disorder is divided into two types: systemic and cutaneous mastocytosis.

Cutaneous Mastocytosis

This type of mastocytosis is the more common type that involves the skin(14).

Cutaneous mastocytosis may be characterized by the following:

  • The appearance of brown or tan spots on the skin with a tendency to spread throughout the body
  • Rapid thickening of the skin and blisters
  • Accumulation of nodules on the skin
  • Lesions that are not itchy

Skin mastocytosis can occur mainly in young children and infants but often fades in their teenage years(15). This abnormality can be caused by the mutations on the KIT gene, which encodes a protein that may control cellular processes like cell division and growth(16).

Topical steroids and oral antihistamines are used to manage cutaneous mastocytosis.

Systemic Mastocytosis

This mastocytosis can be fast-growing (aggressive) or slow-growing (indolent) mast cell accumulation that occurs in the internal organs throughout the body(17).

Systemic mastocytosis encompasses the liver, lymph nodes, bone marrow, and gastrointestinal tract. This abnormality in mast cell development can become cancerous.

As much as 30% of adults are at risk of having cancerous systemic mastocytosis, while 7% of children may develop this disease.


  1. National Cancer Institutes, (n.d.), Mast Cells, retrieved from
  2. Afrin, L. B., (August 2016), Mast cell activation disease and the modern epidemic of chronic inflammatory disease, retrieved from
  3. Akin, C., (June 2017), Mast cell activation syndromes, retrieved from,in%2010%2C000%20to%2020%2C000%20subjects.
  4. American Academy of Allergy Asthma and Immunology, (n.d.), MAST CELL ACTIVATION SYNDROME (MCAS), retrieved from
  5. Akin, C., Op. Cit.
  6. The Mast Cell Disease Society Inc., (n.d.), SYMPTOMS AND TRIGGERS OF MAST CELL ACTIVATION, retrieved from
  7. Romantowski J, Górska A, Lange M, Nedoszytko B, Gruchała-Niedoszytko M, Niedoszytko M. How to diagnose mast cell activation syndrome: practical considerations. Pol Arch Intern Med. 2020 Apr 30;130(4):317-323. doi: 10.20452/pamw.15212. Epub 2020 Feb 25. PMID: 32096778.
  8. American Academy of Allergy, Asthma, and Immunology, Op Cit.
  9., (June 2017), Mastocytosis, retrieved from
  10. NIH National Center for Advancing Transitional Sciences, (n.d.), Cutaneous mastocytosis, retrieved from,mastocytoma%2C%20and%20diffuse%20cutaneous%20mastocytosis.


Author’s Bio

Casey Bloom’s field of studies is concentrated in language and literature. Before writing full-time in the area of health and wellness, she had worked as an advertising creative. She enjoys cooking, dancing, and music.

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