Mast Cell Activation Syndrome (MCAS) is a condition where certain immune cells called mast cells become overly sensitive. These cells normally help protect us from infection or injury, but in MCAS, they release too many chemicals (like histamine) too often—and at the wrong times. This can cause a wide range of symptoms that seem to come and go or shift unpredictably.
Symptoms vary from person to person and can affect many parts of the body. You may experience:
Skin: Itching, rashes, hives, flushing
Gut: Bloating, cramping, nausea, diarrhea, food intolerances
Lungs: Wheezing, cough, shortness of breath
Heart: Fast heart rate, palpitations, dizziness
Brain: Brain fog, fatigue, anxiety, mood changes
Other: Menstrual changes, chronic pain, chemical sensitivity
MCAS can be triggered by things that might seem harmless to others, including:
High-histamine foods such as leftovers, wine, fermented foods, and aged cheese
Strong smells such as perfume or cleaning supplies
Stress, both emotional and physical
Temperature extremes
Hormonal shifts
Infections
Mold, pollen, dust
Medications such as NSAIDs, opioids, and contrast dyes
The goal is to calm the mast cells, reduce inflammation, and support your body’s healing. Treatment often includes a mix of medications, supplements, and lifestyle changes.
H1 blockers (examples: loratadine, cetirizine, fexofenadine) – help with itching, flushing, hives
H2 blockers (example: famotidine) – support digestion and reduce stomach-related symptoms
Mast cell stabilizers (examples: cromolyn sodium, ketotifen) – calm the immune system
Leukotriene inhibitors (example: montelukast) – help with breathing or inflammation
Epinephrine auto-injector – prescribed if there is a risk of severe allergic reactions
Older sedating antihistamines such as diphenhydramine are avoided for long-term use.
These gentle supplements may be recommended:
Quercetin and luteolin – plant compounds that help calm mast cells
Stinging nettle – acts like a natural antihistamine
Vitamin C – supports the immune system and lowers histamine
DAO enzymes – help break down histamine in food
Magnesium and omega-3s – reduce inflammation and support the nervous system
Probiotics (specific strains only) – some are helpful, but others can make symptoms worse; always ask first
Follow a low-histamine diet by avoiding aged cheeses, processed meats, alcohol, vinegar, fermented foods, and leftovers
Eat fresh foods and prepare meals right before eating
Reduce stress with gentle activities such as yoga, deep breathing, time in nature, or journaling
Use clean, fragrance-free personal care and cleaning products
Aim for consistent, restful sleep
Keep a symptom journal to help identify hidden triggers
If you have been told your symptoms are “just anxiety,” “stress,” or “in your head,” please know that MCAS is real. You deserve answers, care, and support.
At Thrive Wellness Center, we specialize in conditions like MCAS that are often missed or misunderstood. Our approach includes:
Personalized treatment plans
Natural and pharmaceutical support
Root cause exploration
Gentle, trauma-informed care
You do not have to navigate this alone.
Questions? Want to learn more?
Call us at 323-389-9191
