Check Out Our Seasonal Specials right arrow
(317) 989-8463 Appointment

Blog Center for Fully Functional Health

Mast Cell Activation Syndrome: When Mast Cells Attack

computer model showing when Mast Cell Activation Syndrome activates

Chronic illnesses with widespread, confusing symptoms are on the rise in America. Advances in medicine have decoded many acute infections and conditions – however, many of the resulting solutions, such as antibiotics, have only contributed to the rise of chronic conditions. In this article, we’re covering Mast Cell Activiation Syndrome, symptoms, treatment, and related conditions.

Today, our bodies are constantly bombarded with toxins, medications, stressors, and triggers – many of which simply didn’t exist a mere 10, 20, or 30 years ago. This collective assault on the body can result in sweeping inflammation and an unbridled immune system.

Overactive immune systems attempting to deal with this influx of toxins/triggers are contributing to conditions such as Mast Cell Activation Syndrome (MCAS).¹ MCAS is a condition we’ve seen on the rise in our practice and across the country. It’s time to shed light on this perplexing condition and spread awareness so that those suffering can find relief and hope.

What Is Mast Cell Activation Syndrome?

Mast cells are a special type of white blood cell that release chemicals called mast cell mediators to communicate as part of the immune system.²

Mast cells secrete many mast cell mediators, which include:

  • Histamine
  • Leukotrienes
  • Prostaglandins
  • Tryptase
  • Heparin
  • Interleukins
  • Tumor necrosis factor – alpha (TNF-ɑ)

A common mediator is histamine – known for its powerful ability to cause inflammation, capillary expansion and permeability, itching, rashes, and hives.³ Histamine is released in response to an allergic trigger otherwise known as an allergen as a means to ‘flush’ it from the system. Histamine can even close the airway, collapse the heart or cause death – within minutes after exposure. Mediators are powerful, effective, and efficient components of our immune system.

These mediators respond to invaders (or perceived invaders) as an inflammatory response. While we need some inflammation to get white blood cells to problematic sites, such as a cut or a scrape, it becomes a problem when mast cells are permanently switched ‘on.’

This is essentially what is happening in a person with MCAS – their mast cells continue to release mediators, which results in multisystem inflammation and symptoms. Often the symptoms of MCAS can look like allergic reactions, though not always. Also, symptoms may come and go in a series of flare-ups, which can present in different parts of the body. As you can imagine, this is part of the reason so many physicians miss a MCAS diagnosis.

a person with rashes on their upper chest and neck

Symptoms of MCAS

Symptoms of MCAS present in episodic events throughout the body including in the skin, gastrointestinal tract, musculoskeletal, circulatory, cardiovascular, respiratory, and neurological systems.⁴ Though MCAS presents differently in everyone, some of the more common symptoms of MCAS include:⁵

  • Flushing
  • Hives
  • Rashes
  • Itching
  • Runny nose
  • Shortness of breath
  • Wheezing
  • Unexplained bruising
  • Diarrhea
  • Nausea
  • Abdominal pain
  • Diarrhea
  • Cognitive dysfunction

In our practice, most patients who come in with MCAS have been diagnosed with and treated for asthma and allergies on and off their entire life. However, by the time they end up in our office, they are hopeless and overwhelmed by the multitude of other symptoms and/or diagnoses they have received.

More often than not they have also been prescribed a laundry list of medications to address every symptom or ‘diagnosis.’ Unfortunately asthma and allergies, which should have been clues to a much bigger issue, are written off as separate events and the opportunity to identify MCAS is missed.

Dr. Scott Antoine and I are both board-certified emergency physicians and certified Functional Medicine doctors. This unique combination of expertise means we have been solving medical mysteries for decades. Through careful ‘detective work,’ we have worked with thousands of patients to solve their personal medical puzzles. Complex diagnoses don’t overwhelm or baffle us. In fact, we developed our Fully Functional® process to systematically dissect and address conditions such as MCAS.

a woman wearing a white shirt grimacing and holding her hip

Conditions Associated With MCAS

Due to the systemic nature of MCAS, it often presents alongside other conditions. Some of these conditions include:

  • Family predisposition⁶
  • Chronic inflammatory response syndrome
  • Allergies
  • Asthma
  • Fibromyalgia
  • Autoimmune disease
  • Infections
  • Candida overgrowth
  • Depression
  • Gut dysbiosis
  • Food sensitivity
  • Eczema
  • Psoriasis
  • Histamine intolerance

This is by no means an exhaustive list, but these are some of the most common conditions we see alongside MCAS.

Diagnosing MCAS

To make a proper diagnosis of MCAS, you are going to need a doctor who is an expert in working up complex medical conditions and what we like to call ‘medical detective’ work. A comprehensive medical history and physical exam are paramount to accurately making this diagnosis. Symptoms such as childhood allergies and asthma may seem relatively benign and unrelated but with MCAS, they are often the first indicator.

We have created a proprietary process that we take all of our patients through called Fully Functional®. IDENTIFY is the first of our five pillars in this process and it is a crucial step in making the diagnosis and ultimately leading to appropriate treatment of MCAS.

We partner with our patients to identify underlying root issues, contributing factors, triggers, and inflammatory processes. With our comprehensive medical history and assessment, we can accurately diagnose and thus begin identifying your personal MCAS root cause(s) and triggers. Only then can we begin the process of building a plan to reduce its impact on your life.

Some of the laboratory work we might recommend includes simple blood and urine tests for the following:

  • Histamine
  • N-Methylhistamine
  • Prostaglandin D2
  • Chromogranin A
person holding a spoon with pills on it

MCAS Treatment

The cornerstone of treating MCAS happens to be the second of the five pillars, REDUCE. We will work to reduce the triggers of MCAS in your life, which may vary over time because your tolerance for each can wax and wane. We will also work on reducing any symptoms associated with MCAS as we continue to address underlying root causes.

Triggers of MCAS include:⁷

  • Alcohol
  • Stress
  • Exercise
  • Fatigue
  • Medications
  • Chemicals
  • Animal venoms
  • Extreme temperatures
  • Infections
  • Sunlight
  • Mechanical irritation
  • High histamine foods

If you have MCAS, avoiding high histamine foods is a relatively easy way to reduce the impact of this trigger. Your reactivity to foods when you have MCAS can be somewhat complex since your body’s response can adapt and change.⁸ It’s best to carefully monitor your intake and reactions, and keep in mind eliminating some items could affect how you react to others.

With that in mind, some high histamine foods include:

  • Fermented milk
  • Sauerkraut
  • Yeast-risen breads
  • Artificial coloring
  • Many processed foods
  • Potato
  • Avocado
  • Eggplant
  • Pumpkin
  • Tomatoes
  • Sweet potato
  • Pickled vegetables
  • Berries
  • Citrus
  • Shellfish
  • Processed and cured meats
  • Walnuts
  • Pecans
  • Green beans
  • Soybeans
  • Spices: Anise, Cinnamon, Cloves, Cayenne, and Nutmeg

This is not a comprehensive list but rather a starting point. You may find your symptoms flare up after eating some of these or that you are able to reduce your reactions by avoiding these. Sometimes people are able to tolerate certain high histamine foods without noticeable symptoms.

In some cases, there may not be exact triggers, in which case we will take an alternative approach. This may include mast cell membrane-stabilizing, treating existing infections, reducing toxin exposure, antihistamines, and histamine avoidance. All of these are potential tools for treating anyone with MCAS.

Additionally, we will add supportive herbs and nutrients, establish a solid routine, implement stress reduction, and heal and support the gut to give your body the best chance at reversing any evidence of this disease.

While our goal is always to prevent or reverse disease, we recognize that it is not always possible. However, it is certainly possible to live a Fully Functional® life with a chronic condition such as MCAS – and although it may take some work, including dietary and lifestyle changes, you do not have to do it alone.

Another one of our pillars is SUPPORT. Not only do we ensure that we are adequately supporting your body physically as well as supporting your immune system, we are passionate about making sure you have the support to be successful on your journey to optimal health!

Dr. Scott and Dr. Ellen smiling

Finding a Functional Medicine Doctor That Specializes in MCAS

Chronic, complicated illnesses, such as Mast Cell Activation Syndrome, often send people from doctor to doctor searching for solutions for months, sometimes even years. It can be a discouraging and seemingly hopeless situation. Too often widespread, confusing symptoms are dismissed by medical professionals because they don’t seem to fit any of the criteria associated with the acute infections and chronic illnesses they are used to treating.

We live in an age where chronic illnesses run rampant. Their complicated nature can leave a lot of practitioners at a loss for what’s going on. Sometimes patients are even turned away – or worse, told that their symptoms are in their head. This is why we developed the Five Pillars of Fully Functional® – to tackle these complicated, chronic conditions and equip patients with a plan that actually heals and restores their life.

We have helped almost 1700 patients through our Fully Functional® process to create fulfilling, healthy lives. Together we will Identify, Reduce, Optimize, Support, and Personalize your MCAS treatment plan so you can get your health and your life back.

You can book an appointment by clicking here. We are also happy to speak with you at (317) 989-8463, Monday-Thursday, from 8AM – 5PM Eastern time.


Schedule an Appointment Today.

The Center for Fully Functional Health® is led by a team of award-winning, internationally recognized physicians, committed to providing personalized, life-changing care.

40 North Rangeline Rd. Carmel, IN 46032

Please note: By submitting this information, you agree to be contacted by The Center for Fully Functional Health via text, call, or email. Standard rates may apply. For more details, please read our Privacy Policy.