Heal Mast Cell Activation Syndrome (MCAS)
- Britta Van Dun
- Jan 9
- 16 min read
Updated: Jan 12
Reclaim Your Health, Reclaim Your Life
This post is dedicated to sharing proven research and anecdotal evidence to help anyone suffering from Mast Cell Activation Syndrome (MCAS).
As an MCASer in recovery, I've been overwhelmed by the intensity, duration, mixed information, cost and progressive nature of this imbalance. It all began with a severe adverse reaction to fluoroquinolone antibiotics in 2007. I went from having a “stomach of steel” to being unable to digest basic foods without allergic reactions. My body perceived almost any food or beverage, medicine or supplement as a threat. If I ate a meal I’d tolerated for years, I’d wake in the middle of the night unable to sleep past 3am. My eyes would be red and puffy, sometimes swollen shut. Hives and rashes appeared on my torso and arms. My ears rang, scalp tingling. During flares, it felt like hot acid was circulating through my veins. I don’t mean to sound mellow dramatic.
Because I’m one of the lucky ones - I only ever went into near-anaphylaxis twice. Many aren’t as fortunate. Over the years, symptoms have come and gone and I’ve enjoyed years of remission, able to eat a more wide variety of foods. After traumatic or stressful episodes, many foods became off-limits and, at one point, my list of safe foods dwindled to10. At the time, it was essential that I followed an elimination diet to balance flares and to help identify triggers. During the reintroduction phase, I knew which specific ingredients triggered reactions. Nightshades, citrus, citric acid, gluten/wheat, coffee, chocolate - the list went on. Unfortunately, I stayed on a very restrictive diet for too long, which led to worsening dysbiosis and reactivity to even “safe” foods. Be mindful of this - elimination diets should only last 6-10 weeks.
What’s more fun - funner? - there’s a psychological component to all of this - I became fearful of most meals, so I was in a stressed/dorsal state as I ate - the opposite of rest and digest. Stress compromises gut motility, increases inflammation and decreases nutrient absorption. My social life suffered because I didn’t feel comfortable joining friends for meals or meeting up at restaurants. My worst flare started mid-pandemic, which only encouraged me to isolate more. Despite long walks, yoga, meditation, eating all the theoretically right foods, my anxiety and reactivity kept climbing. I was stuck in a loop.
Underwhelmed by available research and treatments for folks struggling with Mast Cell Activation Syndrome, Histamine Intolerance and other related conditions, I started digging and experimenting - this is what I learned.
A few years ago, medical professionals didn’t know much about these dis-eases, and, in their unknowing, often made matters worse. Some folks were even gaslit by the medical community. Informed treatment strategies were typically supplement-heavy and trial-and-error, which is challenging for most MCAS folks, because we tend to hyper-react and often flare with the introduction of ill-suited as well as well-matched medications, herbal formulas and supplements. Unfortunately, popular strategies typically rely upon suppressive medications that don't work for highly-sensitive people and further mask underlying imbalances, leading to longer-term complications.
As always, I'm not a doctor. The information presented here is not a substitute for medical or psychiatric care. I simply want to share what I have learned. These Resources are offerings. Offerings to help you re-consider your relationship to Mast Cell Activation Syndrome (MCAS) and to your own body/self, and, to consider potentially novel treatment strategies that emphasize nutrition, energy medicine, trauma-healing, vagal toning, and holistic remedies, as well as allopathic medicines and functional or naturopathic supplements. It was important for me to include solutions from all fields of medicine, because that's what has helped me get back on track. If I can help you get back on track, let's schedule a session.
What is MCAS & What Are Mast Cells?
Mast Cell Activation Syndrome (MCAS) is a chronic multi-system disorder in which mast cells—part of the immune system—become overly reactive. Mast cells reside near blood vessels and nerves in the skin, lungs, and gut. When triggered (even by otherwise benign stimuli), they release mediators like histamine, prostaglandins, leukotrienes, and tryptase, leading to widespread symptoms.
Histamine increases capillary permeability, stimulates nerve endings (causing itching, pain), and plays roles in gut function and neurotransmission. Many people with MCAS also suffer from histamine intolerance, often due to insufficient DAO (diamine oxidase) enzyme to degrade histamine, causing excess accumulation and systemic reactivity.
Common Symptoms of MCAS
MCAS manifests with diverse symptoms affecting multiple systems:
Food, environmental, and chemical sensitivities: reactions to perfumes, mold, medications, additives, or foods
Many allergies, intolerances and sensitivities resulting in hives, rashes, flushing, gastric upset, itching, allergic rhinitis, chronic inflammation, sleep issues
Gastrointestinal distress: nausea, bloating, heartburn, diarrhea, constipation—often diagnosed as IBS.
Anaphylaxis or near‑anaphylactic episodes in severe cases
Overlap with other conditions: frequently co‑exists with POTS, Ehlers‑Danlos Syndrome (EDS), Histamine Intolerance, SIBO and rarely, mastocytosis or HATS (hereditary alpha tryptasemia).
Digestive Issues and MCAS: Gut Dysbiosis / SIBO / Leaky Gut
MCAS is closely linked with a number of underlying and co-occurring issues. Below are the most common variables. While exhausting, this is not an exhaustive list.
Gut dysbiosis is a notable or significant imbalance in the gut microbiome. Gut dysbiosis is most commonly caused by antibiotics and medications, chronic stress and nervous system dysregulation, infections or food poisoning, poor digestion and motility, restrictive or inflammatory diets, and underlying immune or inflammatory conditions.
The most common types of Gut Dysbiosis include SIBO (small intestinal bacterial overgrowth), IMO (intestinal methanogen overgrowth), SIFO (small intestinal fungal overgrowth), colonic dysbiosis (imbalanced gut bacteria in the large intestine), and pathobiont overgrowth (overgrowth of normally harmless microbes that become inflammatory under certain conditions).
The three main types of SIBO are hydrogen-dominant SIBO, methane-dominant overgrowth (IMO), and hydrogen sulfide–dominant SIBO—occurs when excessive bacteria (or methane-producing archaea) inhabit the small intestine, a place they don’t belong in large numbers. These bacterial overgrowths produce lipopolysaccharide (LPS), a potent mast cell activator, fueling a vicious cycle of immune activation and gut inflammation.
Increased intestinal permeability or Leaky gut allows systemic exposure to bacterial byproducts and food antigens, further triggering mast cells.
Low or slow gut motility or movement through the intestines intensifies gut dysbiosis, which compounds mast cell activation.
Compromised Migrating Motor Complex (MMC) The MMC sweeps residual food and microbes out of the small intestine into the large intestine. If that sweeping action is weak, or if the “gate” between the small and large intestine (the ileocecal valve) doesn’t close properly, bacteria linger and overgrow. These microbes can generate gases driving hallmark symptoms like bloating, distention, and discomfort.
Gallbladder sludge or stones contribute to bile stagnation and/or poor fat digestion, which can exacerbate inflammation and gut irritation, also activating mast cells.
Pancreatic insufficiency is a condition in which the pancreas does not produce enough digestive enzymes to properly break down food, leading to malabsorption and gut inflammation that can increase intestinal permeability and immune activation, thereby amplifying mast cell activation and symptom flares.
Low stomach acid (hypochlorhydria) is both a cause and contributor to SIBO, because adequate stomach acid is needed to kill incoming bacteria and trigger proper digestion and motility; when acid is low, bacteria survive, migrate into the small intestine, and are more likely to overgrow.
Mold exposure, heavy metal toxicity and other environmental factors can act as triggers or co-factors in MCAS because they all create imbalances stimulating the immune system, increasing histamine release, and promoting chronic inflammation, which lowers the threshold for mast cell activation and exacerbates symptoms.
Fluctuating hormones, particularly during perimenopause and menopause, can exacerbate MCAS by destabilizing mast cells and increasing histamine release, leading to heightened allergic and inflammatory responses.
COVID-19 infection can trigger or worsen MCAS by causing systemic inflammation, immune dysregulation, and persistent mast cell activation, which may contribute to Long-COVID symptoms.
Vitamin and mineral deficiencies and MCAS can reinforce each other in a bidirectional cycle: malabsorption from MCAS-related gut inflammation, increased intestinal permeability, dysbiosis, and pancreatic or bile insufficiency can lead to deficiencies (especially B vitamins, magnesium, zinc, iron, copper, vitamin D, and vitamin C). Those same deficiencies impair mast cell stabilization, histamine breakdown, mitochondrial energy production, and nervous system regulation—thereby lowering the threshold for mast cell activation and worsening MCAS symptoms.
Effective MCAS care often requires a multi-month, layered strategy to clear biome imbalances, break bacterial biofilms, correct motility, heal permeability, and stabilize immune overactivity.
MCAS is also linked with EDS and POTS
Mast Cell Activation Syndrome (MCAS) is frequently seen alongside Ehlers-Danlos Syndrome (EDS) and Postural Orthostatic Tachycardia Syndrome (POTS), a combination often referred to as “the Trifecta.” While each condition is distinct, they commonly overlap and interact, creating complex, multi-system patterns. They can be tricky to identify because symptoms span immune, connective tissue, and autonomic nervous system dysfunction rather than fitting neatly into a single diagnosis.
EDS is a group of genetic connective tissue disorders characterized by joint hypermobility, fragile or easily bruised skin, chronic pain, fatigue, and frequent injuries or dislocations. POTS is a form of dysautonomia - the nervous system struggles to regulate heart rate and blood pressure, particularly with changes in posture (standing, sitting down, etc.). Common symptoms include rapid heartbeat upon standing, dizziness or fainting, exercise intolerance, brain fog, and profound fatigue. When EDS and POTS coexist with MCAS, symptoms often amplify one another, underscoring the importance of a comprehensive, integrative treatment approach that addresses the body as an interconnected system rather than isolated conditions.
Standard of Care: Allopathic Western Approach to MCAS
Medical therapies aim to block histamine and stabilize mast cells:
H1‑blockers (e.g., loratadine, cetirizine, Claritin) block H₁ histamine receptors in skin, lungs, nerves, and blood vessels—reducing itch, hives, nasal symptoms, bronchospasm.
H2‑blockers (e.g., famotidine, Pepcid) block H₂ receptors in the stomach and other tissues—reducing acid, some systemic histamine effects, and GI inflammation.
Cromolyn sodium (oral) coats mucosal mast cells in the gut and prevents mediator release by stabilizing the cell membrane.
Ketotifen, an H₁ receptor inverse agonist and mast cell stabilizer, prevents degranulation and reduces histamine and inflammatory mediator release.
Phased therapy is recommended: H1 + H2 first, then add cromolyn, ketotifen and/or leukotriene inhibitors if needed.
The most common recommendation is to start any medication as low as possible and slowly titrate up to or close to recommended dosing or when symptoms improve. One medication at a time - give at least 3 days to determine if tolerable. Some folks don’t do well with Zyrtec, for example, but Allegra is their holy grail. Others swear by Cromolyn, but can’t handle the effects of Ketotifen. Early on I learned that Every Body is Different. Try and Try again. Keep Trying.
In terms of phased or step-by-step therapy, the general allopathic MCAS treatment strategy is:
Avoid high histamine foods & consider an Elimination Diet to identify triggers.
Slow reintroduction of ingredients, track symptoms. Avoid those that are activating.
Stabilize mast cell reactivity.
Test to determine underlying cause(s) and co-factors.
If dysbiosis or infection is detected antibiotics are often prescribed.
Improve gut motility & calm underlying inflammation.
Track symptoms and medications/supplements/practices.
Heal MCAS with Functional Medicine & Integrative Strategies
Functional and holistic medicine tends to focus on root causes. Please consult a medical practitioner before attempting any of these on your own!
How to begin healing MCAS holistically:
Low Histamine Diet (I like the SIGHI list). Avoid high histamine foods, which include any fermented foods, aged products like cheese, smoked foods like bacon, leftovers, additives and preservatives. Most meat and fish are very high histamine, unless they are fresh (not aged) or flash frozen (like on the boat when caught). Pork is high histamine as is beef, which is typically aged for at least a week. Other common high histamine foods include spinach, avocado, strawberries, chocolate and coffee, and, histamine liberating foods are citrus, pineapple, and tomatoes. Every body is different, so identifying your personal triggers is key!
Stabilize Mast Cells, such as Nervous system regulation. Through gentle movement, breathwork, vagal toning, adequate sleep, pacing, and trauma-informed stress reduction, mast cell reactivity is greatly reduced. Mast cells are highly responsive to stress hormones. Environmental load is also addressed by reducing exposure to mold, fragrances, chemicals, and extreme temperature changes. Commonly used mast cell–stabilizing supplements in integrative care include bioflavinoids, vitamin C, vitamin D, magnesium, omega-3 fatty acids, and DAO enzymes for histamine breakdown (when appropriate). Gut support with carefully selected probiotics - non-histamine–producing strains AFTER a course of natural antimicrobials if needed. Clean, whole sources of iron and protein are often essential as MCAS reactivity can rob the body of Iron, Ferritin, and B Vitamins. As with all MCAS care, supplements are introduced slowly and strategically.
If SIBO is an underlying cause or contributor, a low Fodmap diet or Elemental diet is often recommended - for a few weeks to months depending upon the treatment strategy. SIBO can be confirmed with a breath test - be sure to test for all three types of SIBO: Hydrogen-dominant is linked with diarrhea; Methane-dominant or Intestinal Methanogen Overgrowth, IMO, is associated with constipation; and Hydrogen Sulfide, which is characterized by stinky gas and mixed diarrhea/constipation. Natural antimicrobials like ADP emulsified Oil of Oregano, AlliMax (extract of garlic, low fodmap) and/or Berberine HCL may be prescribed to clear the bacterial overgrowth and disrupt the biofilm that protects the bacteria. A researched formula, CandiBactin AR or BR may be recommended, depending upon the SIBO type. These are combination antimicrobial/bio-film busters, including Oil of Oregano, Thyme, etc. When SIBO is cleared, gut-healing protocols including spore, single and tailored combination probiotics, prebiotics, and postbiotics may be recommended. It can be a lot of trial and error and folks with SIBO tend to relapse, so patience and determining root cause of dysbiosis is crucial.
It is essential to identify what roles motlity, stomach acid, enzyme insufficiency, histamine intolerance, bile production/movement, etc are playing.
Histamine Intolerance and/or too High Histamine can be treated with supplements like Diamine oxidase (DAO). DAO is the primary enzyme responsible for breaking down dietary histamine in the gut, and low DAO activity can lead to histamine intolerance and increased mast cell activation, worsening MCAS symptoms. DAO supplementation can help reduce the histamine burden from foods, lowering symptom flares and supporting overall mast cell stability.DAO is derived from porcine or bovine kidneys or pea sprouts.
Supplements such as Quercetin, Rutin and Luteolin are bioflavonoids from the same plant that act as natural mast cell stabilizers, inhibiting mediator release. Studies have found they may outperform cromolyn in inhibiting cytokine release in vitro. Luteolin appears to be the most MCASer tolerated of the three. Please see below for supplements, vitamins and minerals that are generally better tolerated by folks with MCAS.
Stress reduction: As mentioned earlier, vagal toning, meditation, breathwork all reduce mast cell sensitivity and systemic inflammation. Click here for posts related to stress reduction and vagal toning.
Improve digestion & gut motility: 1) chew your food well; 2) eat meals in a relaxed environment (aka not in front of TV or while you work or read); choose warm, nourishing cooked whole foods and avoid raw, frozen packaged meals; 3) Walk for 10-15 minutes after a meal or, lay down and practice vagal toning and self massage in a soothing environment; 4) get enough fiber from whole vegetables and fruits - this often requires extra attention from SIBO folks who navigating a low FODMAP diet; 5) A heating pad on the belly, especially after meals, can improve circulation & digestion. Depending on your body's particular needs, one can improve motility with insoluble fibers like PHGG and increase motility with ginger + artichoke extract, bile salts and digestive enzymes. PHGG or Sunfiber is a low FODMAP prebiotic fiber that is a well tolerated insoluble fiber supplement - always start real low and slowly titrate up if tolerated.
If microbial overgrowth, Treat Dysbiosis. Treatment is individualized and often includes low-histamine nutrition, targeted natural antimicrobials or probiotics, enzyme and bile support, gut-lining nutrients, and slow, symptom-guided pacing to avoid mast cell flares.
Address underlying cause(s). If you’re affected by PMDD, perimenopause or menopause, for example, stabilizing estrogen–progesterone fluctuations is key. A combination of exercise, stress reduction, targeted nutrients, and botanical therapies, alongside bioidentical hormone therapy if appropriate. An individualized, low-and-slow approach is essential, as both natural treatments and Hormone Replacement Therapy (HRT) can provoke mast cell reactions if not carefully timed, dosed, and monitored.
Chinese Medicine (TCM) & Acupuncture approach to MCAS
From a Chinese Medicine perspective, MCAS is understood not as a single disease but as a pattern of systemic regulatory imbalance involving immune reactivity, barrier dysfunction, and nervous system hypersensitivity.
TCM practitioners often describe key underlying patterns as Wei Qi (protective or defensive qi) dysregulation, Liver Qi stagnation, Spleen Qi deficiency with Dampness, and constitutional Kidney deficiency — all of which correlate with heightened sensitivity, poor immune containment, digestive weakness, and chronic inflammation often seen in MCAS. A Wei Qi imbalance, for example is thought to underlie hyper-reactivity to external and internal triggers, while Spleen impairment contributes to digestive issues, systemic inflammation, and poor handling of antigens and histamine-rich foods.
Herbal compounds studied for allergic conditions and acupuncture’s positive effects on mast cells support the link between TCM pattern differentiation and mast cell stabilization — restoring organ system harmony mitigates excessive mediator release. In other words . . .
Acupuncture Chinese Medicine can help heal MCAS by:
Improving Overall Immunity, which involves Wei or Protective Qi
Reducing systemic inflammation and calming over-reactive immunity
Supporting digestion and gut motility
Reducing stagnation and improving circulation
Enhancing vagal tone, relaxation, and stress resilience
A word of caution regarding herbs. Some folks have no problem with single ingredient and more complex formulas. Even when hypoallergenic, herbs are often dried and stored (for how long?) and can contain histamine or act as histamine liberators. For highly sensitive individuals, herbal remedies can cause MCAS flares. I’m one of the folks who tried and tried with Chinese Herbal Formulas only to experience mild benefit before kaboom, it would take a week or so to get back to baseline. Anything a Chinese Medicine practitioner prescribes, start low and slow. Only introduce one new thing at a time and give each new ingredient or supplement at least 3 days to suss out if it’s really right for you/your body.
Acupuncture is generally well tolerated by MCAS folks because acupuncture utilizes the bodies own healing mechanisms to restore balance. Acupuncture isn't introducing anything new to the body. That said, if you have a metal allergy, let your acupuncturist know! While hypoallergenic, single use sterile needles are still made of a hypoallergenic alloy. If you have only a mild allergy to metals and you feel safe to try acupuncture, it’s possible to take an antihistamine before a treatment to mitigate histamine spikes. One of my clients takes a homeopathic remedy before sessions and she’s done great with acupuncture despite her allergy. This anecdote is to provide possibilities, it’s not proof it’s always a good idea.
Homeopathic Remedies to treat MCAS
Remedies such as Apis Mellifica, Nux vomica, Arsenicum album, Histaminum hydrochloricum and Natrum muriaticum may help interrupt acute flares triggered by chemical exposures or food intolerances. Remedies are selected based on detailed symptom profiles, e.g., burning throat, nausea, hives, sweating, insomnia, or anxiety during histamine reactions.
Finding the right match homeopathic remedy can be tricky, so consult a homeopath for help. While I'm not a licensed Homeopath, I’ve studied Homeopathy for more than 15 years and am happy to offer ideas.
Mind‑Body & Lifestyle Resources to heal MCAS
Stress reduction and vagal stimulation (deep breathing, humming, yoga) help down-regulate mast cell activation. The vagus nerve (or bundle of nerves is the super highway of the gut/brain axis. Increase vagal tone and you're bringing online the parasympathetic (rest digest) aspect of the nervous system, rather than the sympathetic fight, flight, freeze, fawn. Please see my many posts regarding stress reduction & vagal toning!
Prioritize sleep - the recommended hours was 8, some people thrive with 6.5 to 7 - what does your body call for?
Consistent exercise - yoga, tai qi, qi gong all involve vagal toning and nervous system regulation. In the beginning, and with certain bodies, intensive or vigorous exercise may not be an option. MCAS symptoms can amplify with too much activity. Find what works for you at different stages of your healing.
Low histamine, nutrient dense, calm, consistent meals - if you'd like ideas, just reach out.
The Lifestyle choices and Supplements that work for you! Please see below for supplements, vitamins and minerals that are generally better tolerated by folks with MCAS.
MCAS Healing Roadmap
As you've gathered by now, MCAS is a complex, multi-system condition that often overlaps with POTS, Ehlers-Danlos syndrome, histamine intolerance, SIBO/IMO/SIFO, and impaired digestion and motility. In my own healing and in clinical practice, I’ve found that sustainable progress requires a layered, multidisciplinary approach that prioritizes stabilization before deeper repair.
Foundational support often begins with nutrition, using low-histamine guidelines (SIGHI) alongside FODMAP or Paleo meal plans to reduce immune activation and symptom load. Allopathic pharmacotherapy—including H1/H2 blockers, cromolyn, or ketotifen—can be essential for calming mast cell activity and creating enough stability to tolerate additional interventions.
From there, holistic functional support is introduced thoughtfully and slowly. Nervous system regulation and vagal toning are key. As are gentle strategies to support the migrating motor complex (MMC), such as a walk, twists, and self massage after meals. If needed, one could test-drive the enzyme DAO to breakdown systemic histamine. Or try a mast cell stabilizer like quercitin, rutin or luteolin. Improve gut motility and improve MMC with artichoke extract & ginger root between meals or reduce gut fermentation with Atrantil. Balancing the microbiome is key. This can be done a number of ways, including targeted botanicals and limited use of natural antimicrobials like allicin, berberine, oil of oregano, neem, thyme - what your specific biome is calling for. If the first phase of digestion is out of balance, perhaps pancreatin or low dose bile salts will improve GI functioning. Testing for gall bladder health is also useful.
Healing is accelerated by Chinese Medicine, acupuncture, energy healing, nervous system regulation, and personalized homeopathic support, all of which help restore coherence, resilience, and the body’s capacity to heal without overwhelm. I offer all of this, as well as, intuitive therapeutic support because, let's face it - MCAS can be overwhelming and scary. I'd like to help.
Additional Trusted MCAS Resources
Cleveland Clinic Health Library — MCAS OverviewPatient-friendly explanation of MCAS symptoms, causes, how it's diagnosed (including mast cell mediator testing), and why reactions may occur without clear allergenic triggers.
The Mast Cell Disease Society (TMS) Provides comprehensive educational materials for both adult and pediatric MCAS patients, with templates for school support, disability accommodations, medication guides, and trigger awareness tools. Resources include documents like "Symptoms of MCAS," “Triggers,” and the “Freedom Kit” for communication and advocacy Mast Cell Action.
Allergy & Asthma Network — Mast Cell Disease Toolkit A newly updated Mast Cell Disease Toolkit (published January 2025) that covers symptoms, diagnosis, treatment options, lifestyle adjustments, and support strategies for MCAS and systemic mastocytosis Allergy & Asthma Network.
Primary Care Guide to MCAS (via MastCellAction.org) A concise, medical‑practice–oriented guide detailing clinical presentation, diagnostic criteria, and management approaches, designed to help clinicians recognize MCAS in patients.
Last but not least: MCAS threads on Facebook and Reddit. There were only so many Pubmed articles and clinical posts I could read. My PCP hadn't heard of MCAS and I could only see my Integrative Specialist for 20 minutes every 6 months. I found the most hope and support with online forums. Folks just like us doing the best we can with what we got - and what we got is pretty darn impressive.On Reddit threads in particular, I learned tons about evolving understandings and dynamic, highly individualized treatments for MCAS. In the MCAS and SIBO groups, people are real and funny and brutal and honest and full of opinions. It was real nice to know I was not alone.
If you have been diagnosed with Mast Cell Activation Syndrome or suspect MCAS for you or someone you know, please don't hesitate to reach out. I’m here for you in-person in Tucson AZ and worldwide offering multi-dimensional healing with acupuncture, Chinese Medicine (TCM), reiki, distance energy healing, somatic and craniosacral therapy, and intuitive coaching. Virtual sessions are available by Zoom, FaceTime and phone.
Xx
Britta
Licensed Acupuncturist, Intuitive, Healer, Coach, Energy Medicine Practitioner
📞 917-519-2432
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