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Mast Cell Activation Syndrome (MCAS): Symptoms, Causes, and Solutions

Did you know that fatigue, headaches, hives, rashes, digestive symptoms, and anxiety are all common symptoms of mast cell activation syndrome (MCAS)? Mast cell activation syndrome is a complex health issue that can affect a number of different systems in your body leading to a list of symptoms. The good news is that once you receive the correct diagnosis, you can take some empowered steps, support your body naturally, and regain your health.

In this article, you will learn everything you need to know about mast cell activation syndrome. You will understand what mast cell activation syndrome is and what symptoms, causes, and risk factors it has. I will explain the difference between MCAS and histamine intolerance. You will learn about diagnosis and most importantly, I will share my top natural solutions to help your recovery from mast cell activation syndrome.

What Is Mast Cell Activation Syndrome (MCAS)

Your mast cells play a very important role in your immune system. They are white blood cells found in tissues throughout your body, including your skin, digestive tracts, urinary tract, respiratory tract, reproductive organs, and surrounding nerve. They may be found in your blood as well due to certain infections and diseases that your mast cells may try to repair once the health threat is gone. Your mast cells store inflammatory mediators, including histamine inside granules. When you have an allergic reaction, it will activate your mast cells triggering an allergic response that will lead to the release of histamine and other chemicals.

Mast cell activation syndrome (MCAS) is a complex health issue that involves a number of different systems in your body leading to an array of symptoms. MCAS may develop due to a variety of triggers, including mold, chemicals, toxins, heavy metals, allergens, medications, infections, viruses, food, and alcohol. If you have MCAS, some or all of these triggers can cause your mast cells to release inflammatory mediators, including histamine resulting in unwanted symptoms (1, 2, 3, 4).

Symptoms of Mast Cell Activation Syndrome (MCAS)

Symptoms of MCAS will impact more than one part or system of your body. Symptoms may vary from person to person. Symptoms of MCAS may include:

  • Rashes
  • Hives
  • Itching
  • Heart palpitations
  • Low blood pressure
  • Headaches
  • Chest pain
  • Weight changes, including rapid weight loss or weight gain
  • Digestive trouble, including diarrhea, nausea, and vomiting
  • Loss of appetite or low appetite
  • Anxiety
  • Fatigue
  • Vision changes
  • Weakness
  • Dizziness

Symptoms of MCAS

Mast Cell Activation Syndrome vs Histamine Intolerance

You may notice the similarity between the symptoms of MCAS and histamine intolerance. While the effects of the two can be very similar due to increased histamine in your body, MCAS and histamine intolerance are not the same. 

So what is the difference? Let me break it down for you. Histamine intolerance happens due to adding more histamine to your body than it can handle, usually through a high-histamine diet. Because your body has trouble breaking down the extra histamine, it causes histamine build-up leading to histamine intolerance, which simply means that you have too much histamine in your body.

If you have MCAS, your mast cells get triggers from mold, allergens, viruses, chemicals, toxins, heavy metals, or other triggers, and spill chemicals into your body. One of these chemicals is histamine. This leads to too much histamine in your body resulting in a wide range of symptoms that are very similar to the symptoms of histamine intolerance.

While MCAS is often the primary cause of histamine intolerance, it is not the cause for everyone. Not everyone with histamine intolerance has MCAS, however, I see patients who have both conditions regularly. If you have both conditions, your body will not be able to properly break down the excess histamine, leading to histamine build-up and increased symptoms. If you have histamine intolerance or MCAS symptoms, it is critical that you work with a healthcare professional who can help you with testing, diagnosis, and treatment.

Causes and Risk Factors of Mast Cell Activation Syndrome (MCAS)

Scientists are not fully clear on what causes MCAS. However, a 2013 study has found that about 74 percent of those with MCAS have a first-degree relative with the same condition suggesting that genetics may play a role in developing MCAS (5)

There are also a variety of conditions that go hand in hand with MCAS meaning that if you have one, you may be more likely to develop another. Allergies, asthma, autoimmune conditions, anxiety, irritable bowel syndrome (IBS), Celiac disease, chronic fatigue syndrome, eosinophilic esophagitis, and gastroesophageal reflux disease (GERD) are some conditions that are commonly linked to mast cells activation and MCAS.

MCAS symptoms and episodes are always triggered by something. Common MCAS triggers include:

  • Mold
  • Allergens, including insect bites and certain foods
  • Viruses and infections
  • Medications, including antibiotics, ibuprofen, and opiate pain relievers
  • Chemicals and other toxins, including conventional beauty, body, and cleaning products
  • Heavy metals, including mercury from dental work
  • Smells, such as perfumes and other conventional beauty products
  • Stress-related triggered, including anxiety, pain, exercise, lack of sleep, and rapid temperature changes
  • Hormonal changes, including those related to your menstrual cycle
  • Mast cell hyperplasia, a rare condition that may occur with certain chronic infections or cancers

MCAS triggers

Diagnosis of Mast Cell Activation Syndrome (MCAS)

Because MCAS has so many symptoms that overlap with other conditions, diagnosis can be difficult. It is important that you work with a healthcare practitioner that’s well-versed in MCAS and histamine intolerance. Functional medicine practitioners, such as myself are usually a great choice when dealing with MCAS, histamine intolerance, or any chronic condition or symptoms. 

Your healthcare practitioner will go over your health history and perform a physical exam. They may order diagnostic lab tests that help to diagnose MCAS, including serum tryptase, plasma histamine, PGF2a, and N-methylhistamine. A 24-hour urine test can check for higher levels of markers for mediators during symptomatic episodes. This may be challenging as predicting the future and setting up a doctor’s visit during episodes can be difficult. Some doctors may use medications that block off the effects of mast cell mediators to see how they affect your symptoms. 

You can also expect other blood and urine tests to help to rule out other causes of your symptoms or to identify other health issues. They may recommend avoiding high-histamine foods and trying an elimination diet to watch your body’s reactions and narrow down your triggers. I must emphasize that since diagnosing MCAS can be tricky, it is important that you work with a highly-qualified healthcare practitioner with expertise in MCAS (6, 7).

Solutions for Mast Cell Activation Syndrome (MCAS)

Traditional treatment for MCAS usually includes medications, such as H1 or H2 antihistamines to block histamines, mast cell stabilizers that prevent the release of mediators from mast cells, antileukotrienes to block a certain mediator called leukotriene, and corticosteroids in case of serious edema or wheezing. While medications may help, they don’t consider the entire picture and don’t address potential underlying causes of your condition. 

I offer a natural solution for MCAS through dietary strategies, lifestyle changes, and supplementations to help eliminate your symptoms, allow your body to recover, and regain your full health. Here is what I recommend:

Eat a Low-Histamine Diet

If you have MCAS, I recommend that you follow a low-histamine diet high in nutrients. Begin by eliminating all histamine foods for one to three months. After this Elimination phase, slowly re-introduce them one by one following The 4-Phase Histamine Reset Plan. To understand each step of this simple yet refined system, I recommend that you read my book, The 4-Phase Histamine Reset Plan: Getting to the Root of Migraines, Eczema, Vertigo, Allergies and More where I explain everything about histamine intolerance and MCAS and each phase of the plan in detail and offer my favorite low-histamine recipes to nourish your body. 

Gently Support Detox Pathways

MCAS is often triggered by mold, heavy metals, chemicals, and viruses. Remove toxic chemicals from your life and choose natural, organic, or DIY beauty, body, and cleaning products. Make sure that your home is free of mold and invest in a high-quality air-filtration system like this. Support detoxification by sweating through exercise and infrared sauna sessions. Hydrate well to support detoxification through urine. 

Support Your Gut 

Addressing potential underlying gut health issues including yeast overgrowth and microbiome imbalance is critical to support your recovery and set your body up for success. If you are dealing with both mast cell activation syndrome (MCAS) and gut health issues, I recommend working with a functional medicine practitioner (like me) to test your gut and see if opportunistic bacteria, yeast overgrowth, parasites, H. pylori and/or leaky gut can be what is driving your histamine issue. 

Support Your Liver

Support your liver which is a major detoxifying organ that’s critical for your recovery from both MCAS and histamine intolerance. I recommend Optimal Reset Liver Love, a powerful blend of botanical and mushroom extracts and N-Acetyl-L-Cysteine (NAC)  for optimal liver function, detoxification, hormonal health, and brain function (10).

Take HistoRelief

To support your body and reduce symptoms of MCAS or histamine intolerance, I recommend HistoRelief. This mast stabilizing supplement is a synergistic blend of nutrients including Tinofend®, quercetin, nettle leaf, vitamin C, and bicarbonate salts, that provides natural support to balance your immune response, inflammation reduction, and histamine release (11).

solutions for MCAS

Final Thoughts

Mast cell activation syndrome can affect a number of different systems in your body leading to a list of symptoms, including hives, rashes, headaches, weight changes, digestive issues, weakness, fatigue, and anxiety. Working with a well-informed functional health practitioner and receiving the correct diagnosis is key to recovery. By following the steps I outlined you can take back the control and regain your health and happiness without symptoms of MCAS.

If you are dealing with symptoms of mast cell activation syndrome, I invite you to schedule a consultation with us. I can help to identify the root cause of your problems and recommend a personalized treatment plan to repair your body and regain your health and well-being. Schedule your consultation here. You can also get started on your own with my Histamine Online Program.

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Hi, I am Dr. Becky Campbell. I work with men and women who’ve had a health set back and are willing to do whatever it takes to reach optimal health so they can perform their best in their careers and be fully present with their family again.