Hidden Infections and Mast Cell Activation Syndrome: What You Need to Know

Jill Carnahan, MD

Most of us have experienced some form of an allergic reaction in our lives. Whether it’s sneezing, watery eyes, an outbreak of hives, or an upset tummy – most of us can attest to the unpleasant effects of an allergic reaction.

Now imagine being hit with severe and even debilitating allergy symptoms seemingly out of the blue. Navigating life becomes like tiptoeing through a battlefield laden with landmines – never knowing when or what might set off an allergic response.

Unfortunately, this is the reality for a growing number of people suffering from a condition known as mast cell activation syndrome. Today we’re going to dive into exactly what mast cell activation syndrome is and what might be an underlying cause. Plus, we’ll look at how this complex condition may also give us some insight into understanding COVID-19.

What Are Mast Cells?

Mast cells are important immune cells that essentially act as alarm cells, signaling your immune system to ramp up. You see, mast cells contain granules that store inflammatory mediators like:¹

Histamine
Heparin
Chondroitin sulfate
Proteases
Leukotrienes
A variety of cytokines

When stimulated, your mast cells undergo degranulation – when they rapidly release the inflammatory mediators stored within the cell and therefore initiate an immune response.

Because mast cells are designed to protect you from potentially harmful foreign invaders, they are strategically located in areas of your body that most frequently come into contact with the external environment. That means while mast cells can be found in most tissues, they are typically found in higher concentrations in your airways, intestines, and skin.²

So, What Exactly Happens When Mast Cells Degranulate?

Because mast cells reside in areas of the body that are in direct contact with your environment, it allows them to be among the first cells to respond upon contact with foreign invaders. If an irritant or potentially harmful molecule is detected by your mast cells, they “sound the alarm” and initiate an inflammatory cascade that includes:³

Activating and recruiting other immune cells to target and eliminate the invader
Increasing vascular permeability
Inducing vasodilation
Stimulating bronchial and smooth muscle contraction

This rapid initiation of the immune response makes mast cells invaluable when it comes to immune surveillance and healthy immune response. But if the delicate balance of immune activation and subsequent deactivation get thrown out of whack, it can wreak havoc on your entire body.

What Is Mast Cell Activation Syndrome (MCAS)?

In mast cell activation syndrome, you have a normal amount of mast cells floating around in your body, but they begin to malfunction. Mast cell activation syndrome occurs when your mast cells overreact, releasing too many inflammatory mediators too frequently. This inappropriate and exaggerated response causes your immune system to essentially go haywire.

Let’s take a look at some of the more commonly seen mast cell activation syndrome symptoms. associated with this abnormally high secretion of inflammatory mediators.

What Are the Symptoms of Mast Cell Activation Syndrome?

The abnormally high secretion of inflammatory mediators can cause a variety of unpleasant, and sometimes even debilitating mast cell activation syndrome symptoms. Because mast cells reside in nearly all of your tissues and because their degranulation sets off an inflammatory response that spreads throughout your body – a flare-up can affect a number of your body systems such as:⁴

Your skin: Causing hives, itching, swelling, and/or flushing
Your digestive tract: Causing nausea, vomiting, diarrhea, abdominal cramping, and/or bloating
Your cardiovascular system: Causing low blood pressure, rapid pulse, passing out, and/or vascular permeability (inflammation and swelling)
Your respiratory system: Causing wheezing, shortness of breath, coughing, increased mucus production, and/or asthma-like symptoms
Your brain: Causing brain fog, anxiety, headaches, difficulty concentrating, sleeplessness, neuropathic pain, and/or vertigo

One of the cardinal aspects of mast cell activation syndrome is the cyclic waxing and waning of symptoms with varying degrees of intensity. This is because when your mast cells are malfunctioning and hypersensitive, there are a number of triggers that can send them into overproduction mode. Let’s take a look at some of the underlying causes and triggers that can lead to a flare-up of MCAS symptoms.

What Triggers a Mast Cell Activation Syndrome Flare-Up?

Anything that your body (correctly or incorrectly) identifies as a potential threat can cause your mast cells to begin degranulating and set off the inflammatory cascade. Triggers will vary from person to person and can change over time. And while we can’t always be 100% sure what the triggers are when it comes to mast cell activation syndrome, we do know some of the potential triggers include:^5,6

Environmental irritants: Sun exposure, significant temperature or altitude changes, mold, dust, pollen, animal dander, heavy metals, pollution.
Noxious smells: Perfumes, smog, exhaust, synthetic fragrances, cleaning supplies.
Certain medications: Narcotics, antibiotics, NSAIDs, anesthetics, opioids, muscle relaxers, some supplements, contrast dyes used in medical imaging.
Physical stimulation: Pain, trauma, exercise, friction and vibration, fatigue.
Hormonal changes: Estrogen and progesterone shifts such as during a woman’s menstrual cycle, a-MSH, CRH, emotional stress.
High histamine foods and beverages: Fermented foods, alcoholic beverages, aged meat and cheese, nuts, certain fruits and veggies (for a more complete list of high histamine foods, check out my article about What You Need to Know When Histamine Goes Haywire).
Infection: Virus, bacteria, fungi, parasites.

Now let’s take a little deeper look at the connection between mast cells and infections.

The Link Between Infections and Mast Cell Activation Syndrome

Infections can simply be a trigger for a mast cell activation syndrome flare-up, but it can also be an underlying cause. You see, sometimes a severe, chronic, or underlying infection can essentially force your immune system to stay in the “on” position by causing:^7,8,9

Pathogen latency: After initial infection, some pathogens can remain dormant in the body – evading detection by the immune system and causing low-level inflammation.
Chronic production of immune mediators: An overproduction of proinflammatory mediators can throw your immune system out of whack and diminish your body’s ability to regulate inflammation.
Decreased function of natural killer cells: Natural killer cells are immune cells responsible for engulfing and removing infected cells. When their function is depressed, you become more susceptible to infections, further depleting your immune system’s resources.
T-cell disruption: T-cells are another type of immune cell that have numerous functions, including mediating whether inflammation needs to be ramped up or down. So when your T-cell’s activation and deactivation become imbalanced, it disrupts the homeostasis of your immune system.

This dysfunction of your immune response can result in the malfunction and hyper reaction of your mast cells – thus triggering the flares of hyper-inflammation seen in mast cell activation syndrome.

Understanding this underlying mechanism of action associated with mast cell activation syndrome may also be able to give us some clues as to how we can address another serious health concern: COVID-19.

Mast Cell Activation Syndrome and COVID-19

We still have many unanswered questions when it comes to COVID-19. But what we do understand, is that COVID-19 cases that spiral into the territory of severe and life-threatening tend to have something in common – an excessive secretion and accumulation of inflammatory mediators and immune cells.¹⁰

The presentation of critical COVID-19 cases and mast cell activation syndrome have striking similarities, which could potentially give us some insight as to how we can address this emerging virus.

For example, research has indicated that natural molecules such as polyphenolic flavonoids have the ability to inhibit mast cells – therefore slowing down mast cell-associated inflammation.¹¹ Pursuing treatments that address the underlying issues associated with severe COVID-19 cases – such as an overzealous mast cell response – could potentially yield promising results in finding a cure for COVID-19.

To learn more about COVID-19 I recommend checking out the following articles:

More time and research is needed to truly understand COVID-19 and the role mast cell activation plays.

Worried About Mast Cell Activation Syndrome?

Mast cell activation syndrome is a serious condition that is notoriously underdiagnosed – and cases are on the rise. If you’re concerned that you or a loved one may have mast cell activation syndrome, I encourage you to seek out the guidance of an experienced Integrative and Functional Medicine Practitioner. They’ll help you address the root cause, and come up with a comprehensive plan to address your symptoms.

If you’ve been diagnosed with MCAS, there are also some easy-to-take supplements that can have a huge impact on controlling your symptoms and regulating inflammation. My favorites are:

Hist Assist: This unique blend of antioxidants, flavonoids, proteolytic enzymes, and botanicals is designed to offer comprehensive support for elevated histamine levels.
Histamine Blocker: This enzyme formula keeps histamine levels in check with its potent dose of DAO – the primary enzyme responsible for breaking down food-derived histamine.
Quercenase: Quercetin, one of the primary ingredients in this supplement, is a key flavonoid that helps stabilize mast cells. Bromelain, one of the other key ingredients, has been proven to help maintain a healthy cytokine balance and enhance your immune function.

You can find all of these supplements through my online store. And you can even get 10% off your first order by clicking here!

Additional Resources for Understanding MCAS

For more resources and information on mast cell activation syndrome, check out the following articles for a better understanding of this complex condition:

When it comes to dealing with health issues – especially complicated ones such as mast cell activation syndrome – I believe it’s crucial to stay educated and proactive. Because when it comes to your health, you are always your own best advocate.

When It Comes to Your Health, You’re in the Driver’s Seat

While mast cell activation syndrome can be frustrating and even debilitating at times, the good news is, you are not at the mercy of this diagnosis. Educating yourself and taking action based on that knowledge is your most powerful weapon in defending and improving your health. Because when it comes to your health, you are in the driver’s seat.

That’s why I’m dedicated to bringing you up-to-date, research-backed information – to arm you with the tools you need to take control of your own health and well-being. If you enjoyed this article and want to learn more, I suggest starting with the additional articles linked above and then heading over to my blog. And if you’re ready to take it even deeper, you can sign up for my newsletter to get all my best advice and resources delivered straight to your inbox.

References

* These statements have not been evaluated by the Food and Drug Administration. The product mentioned in this article are not intended to diagnose, treat, cure, or prevent any disease. The information in this article is not intended to replace any recommendations or relationship with your physician. Please review references sited at end of article for scientific support of any claims made.

Published January 13, 2024

About the Author

Jill C. Carnahan, MD, ABIHM, IFMCP, was dually board certified in Family Medicine in 2006-2016 and in Integrative Holistic Medicine since 2005. She founded the Methodist Center for Integrative Medicine in Peoria, Illinois in 2009 and worked there as medical director. Then in 2010, she moved to Boulder, Colorado and opened Flatiron Functional Medicine where she has a widely sought-after medical practice with a broad range of clinical service including nutritional consultations, chiropractic therapy, naturopathic medicine, acupuncture, and massage therapy.

Dr. Jill is survivor of both breast cancer and Crohn’s disease and passionate about teaching patients how to live well and thrive in the midst of complex and chronic illness. She is also a widely sought-after inspirational speaker and travels around the world to teach physicians the principles of personalized and functional medicine. She has been featured in Shape Magazine, Parade, Forbes, MindBodyGreen, First for Women, Townsend Letter, and the Huffington Post as well as seen on NBC News and Health segments with Joan Lunden. She recently published her prescriptive memoir, Unexpected: Finding Resilience Through Functional Medicine, Science, and Faith, was published in 2023.