Mast Cell Activation Syndrome (MCAS): Understanding the Body’s Overreaction with Gentle Support
- Rosetta Kawauchi CHHP CTN
- Aug 2
- 6 min read
By Rosetta Kawauchi, BCND - Naturopath | Essence of Healing LLC, Okemos, MI USA | In-person or Telehealth
Have you ever felt like your body is responding too strongly to things that shouldn’t be a big deal?
Perhaps your skin flares up one day without warning. The next, your digestion is upset, your heart races, or your face suddenly flushes and swells. You go for testing, everything appears “normal.” Allergies? “Inconclusive.”
If this sounds familiar, know that you’re not imagining it.
Your body may be signaling a deeper imbalance, one rooted in your immune system’s mast cells.
For many people, this invisible process is known as Mast Cell Activation Syndrome, or MCAS—a condition that often evades traditional diagnosis but can deeply affect daily life. In this article, we’ll explore what MCAS is, how it behaves in the body, and how a compassionate, natural approach may bring support and relief.
What Is Mast Cell Activation Syndrome (MCAS)?
Mast cells are immune cells that serve as sentries for your body’s defense system. They help you respond to injury or infection by releasing chemical messengers—histamine, cytokines, leukotrienes, and prostaglandins—that signal inflammation.
These chemicals are essential during emergencies, such as infections, allergies, or trauma. However, in MCAS, mast cells become overly reactive and release these chemicals too easily, too frequently, and often without a clear threat. This can lead to widespread, unpredictable symptoms that affect nearly every part of the body.
Unlike mastocytosis (a condition where mast cells are overproduced), MCAS involves normal numbers of mast cells that behave abnormally, over-releasing their contents and triggering chronic inflammation and hypersensitivity.
Where Are Mast Cells Found?
Mast cells are located wherever your body interfaces with the outside world:
Skin
Lungs
Digestive tract
Blood vessels
Brain and spinal cord barriers
Lymphatic system
Sinuses and mucous membranes
These cells play an important role in surveillance, standing guard at the body’s entry points. But when they become hyper-vigilant—as in MCAS—they respond to benign inputs like food, scents, or stress as though they are threats, flooding your system with inflammatory signals.
Common Symptoms of MCAS
Because mast cells are found throughout the body, MCAS can feel like a condition that “moves” from one system to another. One day it’s digestive trouble, the next it’s fatigue, and later, it’s hives or panic-like symptoms. This variation contributes to why the condition is so often overlooked.
Skin & Face:
Flushing
Hives or itching
Swelling (especially around eyes, lips, throat, or underarms)
Redness, rashes, or eczema
Brain & Mood:
Brain fog and poor memory
Anxiety or irritability
Panic-like sensations
Sensitivity to sound, light, or chemicals
Migraine-type headaches
Cardiovascular & Respiratory:
Rapid heartbeat (tachycardia)
Dizziness or fainting
Shortness of breath
Chest tightness (not related to heart disease)
Digestive & Gut:
Bloating or cramping
Nausea or diarrhea
Acid reflux or indigestion
Food intolerances or sensitivities with no clear allergy
Whole-Body:
Profound fatigue
Temperature instability (feeling too hot or too cold)
Muscle or joint discomfort
“Allergic” symptoms with normal allergy tests
Credit: me-pediatric.org
The Lymphatic System & MCAS: A Vital Connection
One lesser-known but powerful connection in MCAS is with the lymphatic system, the body’s natural waste removal and immune surveillance network.
Why does this matter? Mast Cells and Lymph Live Side by Side
Mast cells are located in and around lymphatic vessels and nodes. When mast cells release histamine and other mediators excessively, this can irritate and inflame surrounding lymph tissue, causing congestion.
Histamine Thickens Lymph Fluid
Excess histamine can make lymphatic fluid thicker and slower-moving. This sluggish flow means toxins and cellular waste take longer to clear, keeping inflammation active.
Detoxification Becomes Overloaded…
When lymph is slow and the liver and gut are already burdened, detoxification grinds down. This buildup worsens symptoms and contributes to that “stuck” feeling so common in MCAS.
Gentle Lymphatic Support Can Help
Natural practices like manual lymphatic drainage (MLD), castor oil packs, and warm, electrolyte-rich fluids can support movement and reduce chemical buildup, helping your body regain balance.
What Can Trigger MCAS?
Understanding your unique triggers is a vital part of managing MCAS. Some triggers are avoidable; others may be minimized with preparation.
Common triggers include:
Physical or emotional stress (even positive excitement)
Viral, bacterial, or fungal infections
Mold exposure
Environmental chemicals (cleaners, perfumes, off-gassing plastics)
Hormonal shifts, such as menstruation, perimenopause, or puberty
Extreme temperatures or changes in weather
Exercise (particularly intense exertion)
Certain medications or supplements
High-histamine foods, including:
Fermented foods (sauerkraut, kimchi, vinegar)
Aged cheeses
Smoked meats
Citrus fruits
Leftovers (histamine builds up over time)
Natural Ways to Support the Body in MCAS
Living with MCAS is not about constant restriction, it’s about learning what supports your body best, so that it can come out of “high alert” mode. Many people find significant relief through gentle, holistic approaches.
1. Support Mast Cell Stability:
Natural mast cell stabilizers help calm reactivity and reduce the release of inflammatory mediators:
Quercetin – A powerful flavonoid with antihistamine and anti-inflammatory effects
Luteolin – Known to reduce neuroinflammation and mast cell activity
Stinging nettle – Traditionally used for allergy and histamine symptoms
Vitamin C – Helps degrade histamine and supports immunity
DAO enzyme – Breaks down histamine in the digestive tract (especially helpful for histamine-sensitive individuals)
2. Encourage Detoxification and Drainage:
Reducing your body’s inflammatory load helps mast cells feel “less threatened.”
Manual Lymphatic Drainage (MLD) – A gentle massage technique that promotes lymph flow
Castor oil packs – Applied to the abdomen or liver area to improve circulation and drainage
Hydration with electrolytes – Supports kidney, liver, and lymphatic function
Infrared sauna – May help sweat out toxins (use cautiously if sensitive to heat)
3. Calm the Nervous System:
Because stress is a major trigger, soothing the nervous system is foundational.
Breathwork or slow, rhythmic breathing – Activates the parasympathetic (“rest and digest”) system
Vagus nerve support – Gentle humming, gargling, or cold exposure can help regulate mast cell reactivity
Magnesium (glycinate or topical) – Supports relaxation, sleep, and cellular repair
Low-stimulation environments – Especially helpful during flare-ups
4. Modify Your Diet with Care:
Many people find relief by adjusting their diets, not with harsh elimination, but with mindful nourishment.
Avoid leftovers, fermented, and aged foods
Favor fresh, home-cooked meals
Stick to low-histamine foods such as:
Cooked vegetables
White rice or sweet potato
Fresh meat or fish (frozen immediately after purchase)
Rotate foods to avoid building new sensitivities
MCAS Often Coexists With:
MCAS rarely stands alone. It is often part of a larger picture involving dysregulation of the immune and nervous systems. Conditions that frequently overlap with MCAS include:
Long COVID
Chronic fatigue syndrome (CFS/ME)
Fibromyalgia
Postural Orthostatic Tachycardia Syndrome (POTS)
Ehlers-Danlos Syndrome (EDS)
Mold-related illness
Autoimmune conditions, such as Hashimoto’s thyroiditis or rheumatoid arthritis
Understanding these connections can help explain why some people experience such a broad and persistent range of symptoms—and why a gentle, whole-body approach works best.
A Gentle Reminder
If you are navigating MCAS, please remember:
You are not broken.
Your body is not wrong.
It is trying, fiercely and bravely, to protect you.
Although the process may feel frustrating, confusing, or even lonely, there is hope. Your body is speaking to you—sometimes loudly. When we listen carefully, and respond with support rather than suppression, we begin to see true healing unfold.
Progress may not always be linear. There may be setbacks or flare-ups. But with consistent care, a nurturing environment, and individualized natural strategies, your system can begin to calm.
Contact: Dr. Rosetta Kawauchi, BCND- Board Certified Naturopathic Doctor
1-517-997-1214
Disclaimer: Rosetta Kawauchi, BCND is not a medical provider. Dr. Rosetta is a Board Certified Naturopathic Doctor and a Certified Holistic Health Practitioner. Dr. Rosetta does not diagnose, prescribe, treat, or cure medical conditions. This article is for educational purposes and is not a substitute for medical advice. Always consult your licensed medical healthcare provider before beginning new supplements or therapies.
References:
1. National Institutes of Health, Genetic and Rare Diseases Information Center. (n.d.). Mast Cell Activation Syndrome. In GARD. Retrieved from https://rarediseases.info.nih.gov
(GARD is an NIH program)
2. Valent, P., Hartmann, K., Bonadonna, P., Niedoszytko, M., Triggiani, M., Arock, M., & Brockow, K. (2022). Mast Cell Activation Syndromes: Collegium Internationale Allergologicum Update 2022. International Archives of Allergy and Immunology, 183(7), 693–705. https://doi.org/10.1159/000524532
(PMCID: PMC9393812)
3. Kimata, M., Shichijo, M., Miura, T., et al. (2000). Effects of luteolin, quercetin and baicalein on immunoglobulin E‑mediated mediator release from human cultured mast cells. Clinical & Experimental Allergy, 30(4), 501–507. https://doi.org/10.1046/j.1365-2222.2000.00575.x
4. Theoharides, T. C. (2009). Luteolin as a therapeutic option for multiple sclerosis. Journal of Neuroinflammation, 6, Article 29. https://doi.org/10.1186/1742-2094-6-29
(PMCID: PMC2768692)
5. Weng, Z., Patel, A. B., Panagiotidou, S., & Theoharides, T. C. (2015). Luteolin is more potent than cromolyn in their ability to inhibit mediator release from cultured human mast cells. Allergy & Clinical Immunology (Karger). Retrieved from PubMed (2024)
6. Woosley, T. (2025, May 15). What is Mast Cell Activation Syndrome? Natural Health Research. Retrieved from https://www.naturalhealthresearch.org
7. Layne, D. (2025, February 13). Natural Remedies for Mast Cell Activation Syndrome (MCAS). Earth Clinic. Retrieved from https://www.earthclinic.com
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