A Functional Medicine Guide to

Mast Cell Activation Syndrome (MCAS)

Mast Cell Activation Syndrome (MCAS) is a complex condition gaining recognition in the world of functional medicine. It involves the inappropriate release of mediators from mast cells, a type of white blood cell that plays a crucial role in the body’s immune response. When these cells release their mediators too frequently or abundantly, it can lead to a wide range of symptoms that affect multiple organ systems.

Histamines and Mast Cells: What’s the Difference?

To understand MCAS, it’s important to differentiate between histamines and mast cells. Histamines are chemical compounds that serve as mediators in the body’s immune response, especially during allergic reactions. Mast cells, on the other hand, are immune cells that store and release these mediators, including histamines, tryptase, and other substances. When mast cells are activated, they release these compounds, leading to symptoms such as swelling, flushing, difficulty swallowing, anxiety, and tachycardia. Mast cells are primarily found in the respiratory and intestinal tracts, as well as in the skin.

Symptoms and Triggers

MCAS can present with a variety of symptoms that often mimic other conditions, leading to misdiagnosis.

Common symptoms include:

  • Allergy-like symptoms such as itching and watery eyes and nose
  • Mouth and lip swelling
  • Flushing
  • Difficulty swallowing
  • Anxiety and tachycardia
  • Frequent emergency room visits, often mistaken for heart attacks or panic attacks but is typically related to low blood pressure

Triggers for MCAS vary widely from person to person and can include:

  • Lack of sleep
  • Alcohol
  • Stress (Corticotropin-releasing factor or CRF)
  • Medical procedures
  • Gut dysbiosis or SIBO
  • Environmental toxins like smoke and mold
  • Heat or weather changes
  • Fever or infections
  • Too much or too little exercise
  • High histamine foods

Up to 17% of the total population may be affected by MCAS, with a significantly higher prevalence among Caucasian women. However, men and people of other races can also develop this condition.

Connection to Super Pentad Syndrome, Post-Viral Illness, and Digestive Conditions

Super Pentad Syndrome is a condition where patients experience a combination of five severe chronic illnesses, including MCAS. This syndrome highlights the interconnectedness of various chronic conditions and the significant impact of mast cell dysfunction. Post-viral illness, such as long COVID, has also been linked to MCAS, with patients experiencing lingering symptoms due to ongoing mast cell activation. We also see increased likelihood in patients who have had a history of mold exposure. 

MCAS is also associated with many digestive conditions, such as Irritable Bowel Syndrome (IBS). The constant release of mast cell mediators can lead to gastrointestinal symptoms like abdominal pain, bloating, diarrhea, and constipation, which are common in IBS. Recognizing the connection between MCAS and digestive disorders can help in developing more effective treatment plans.

Diagnosis and Management

Diagnosing MCAS involves meeting specific criteria, including:

  • Clinical signs and symptoms affecting two or more organ systems
  • Elevated levels of mast cell mediators such as tryptase or histamine during a flare. These mediators are usually not elevated unless a flare is occurring
  • Having a favorable response to medications with mast cell stabilizing agents or mast cell mediators

Flare-ups can be long-lasting, with patients experiencing periods of symptom exacerbation and relief. It is crucial to seek care from knowledgeable providers who understand the nuances of MCAS.

Management of MCAS typically involves a combination of:

  • Mast cell stabilizers like cromolyn sodium or ketotifen
  • H1 and H2 antihistamines such as Zyrtec, Claritin, and Pepcid
  • Lifestyle modifications, including low histamine diet, proper exercise and sleep, stress and gut health management
  • Nutritional supplements

Supplements for MCAS Management

In addition to medications, several supplements can help stabilize mast cells and reduce symptoms. These include:

  • Quercetin: A natural flavonoid with anti-inflammatory and mast cell-stabilizing properties. (Resveratrol, luteolin, and curcumin share similar mast cell stabilizing properties)
  • DAO enzymes: Taken before meals, helps to reduce histamine release into the body and reduce symptoms 
  • Vitamin C: Acts as a natural antihistamine, helping to lower histamine levels and support the immune system.
  • Nettles: Known for their anti-inflammatory properties and ability to reduce histamine production, nettles can help manage symptoms by acting like a natural antihistamine.

The Role of Functional Medicine

Functional medicine offers a holistic approach to managing MCAS by addressing the root causes and contributing factors. This includes:

  • Tailored nutrition plans to avoid trigger foods
  • Stress reduction techniques to minimize flare-ups
  • Use of supplements to support immune function
  • Medications to stabilize mast cells and control symptoms

Working with a functional medicine practitioner can help create a personalized treatment plan that addresses the unique needs of individuals with MCAS, promoting healing and system regulation.

Do I Have Mast Cell Activation Syndrome?

If you suspect you might have MCAS, consider taking a Mast Cell Mediator Release Syndrome questionnaire. This can help identify potential symptoms and guide you in seeking appropriate medical advice.

MCAS is a challenging condition, but with the right support and management, individuals can find relief and improve their quality of life.

For those seeking expert care, we have Dr. Alicia McCubbins, a naturopathic doctor specializing in mast cell disorders, and our functional nutritionist, Cindi Lockhart. Both providers offer comprehensive support and personalized treatment plans to help manage MCAS effectively.