All About Mast Cell Activation Syndrome: What Is It and How to Treat It

If you are suffering from a strange array of symptoms that traditional medicine can't explain, mast cell activation syndrome may be to blame. Symptoms of this disorder can include skin rashes, headaches, fatigue, digestive issues, and more. However treating MCAS with a functional medicine approach can help get to the root of the problem and provide relief from these often debilitating symptoms.

Let's learn what MCAS is, how it's diagnosed, and treatment options using a functional medicine approach.

What is mast cell activation syndrome?

Mast cell activation syndrome (MCAS), is a chronic disorder caused by the overactive response from a group of specialized immune cells known as mast cells. Mast cells are a type of danger signal for the immune system. They store inflammatory defense compounds, including histamine, which is the all-too-well-known culprit behind allergic reactions. 

When a mast cell detects a harmful invader, they signal the release of pro-inflammatory molecules, including histamine, that tell the immune system it’s time to fight back (1).

In a healthy reaction, mast cells trigger an inflammatory response, the immune system springs into action to defend the body, and then your immune system tamps down the inflammation to return to a normal baseline—the threat now resolved.

But with MCAS, mast cells begin to malfunction. Instead of turning off after they’ve done their job, they keep releasing proinflammatory signals. What’s meant to be a protective response from your mast cells instead triggers distressing local and systemic symptoms.

Related: Warning Signs for Chronic Inflammationauto

Symptoms of mast cell activation syndrome

Because mast cells are designed to protect the body, they are located in higher concentration in critical areas that most frequently come into contact with the environment—in airways, intestines, and skin (2). Because of this, mast cell disorders often cause symptoms in the skin, gut, or respiratory system (3).

• Skin-related symptoms of mast cell disorders: Itching, swelling, and/or flushing (with or without a rash)
• Gastrointestinal symptoms: Nausea, vomiting, diarrhea, abdominal pain, reflux, or bloating
• Cardiovascular symptoms: Changes in blood pressure or heart rate
• Respiratory-related symptoms: Shortness of breath, coughing, itchy throat, and/or asthma-like symptoms
• Brain and mental health symptoms: Brain fog, fatigue, headaches, difficulty concentrating, bone/muscle pain.

Similar to other immune-related diseases (autoimmunity, etc.) MCAS often causes flare ups triggered by stress, illness, or other stimuli, followed by a period of regularity. One of the hallmark signs of MCAS is a cyclical waxing and waning of symptoms with varying degrees of severity depending on what exactly triggers overactive mast cell activity (4). 

What triggers MCAS flare up?

MCAS occurs in response to anything that your body thinks is a threat—whether it really is or not. What triggers MCAS symptoms varies from one person to another, and they may change over time. Some of the identifiable triggers of MCAS include (5):

• Heat, cold or sudden temperature changes
• Stress: emotional, physical, including pain, or environmental (i.e., weather changes, pollution, pollen, pet dander, etc.)
• Exercise
• Fatigue
• Drugs (opioids, NSAIDs, antibiotics and some local anesthetics) and contrast dyes
• Natural odors, chemical odors, perfumes and scents
• Venoms (bee, wasp, spiders, fire ants, jellyfish, snakes, biting insects, such as flies, mosquitos and fleas, etc.)
• Infections (viral, bacterial or fungal)
• Irritation on the skin, friction, or vibration
• Sun/sunlight

Hormonal changes, especially estrogen fluctuations may also influence mast cell activity (6). 

High histamine foods and beverages include fermented foods, alcohol, aged meat and cheese, nuts, and certain fruits & vegetables.

Related: Hidden Triggers of Autoimmune Disease