Mast Cell Activation Syndrome

Mast Cell Activation Syndrome (MCAS) features inappropriate mast cell activation, causing not only typical symptoms of allergy but also a host of other symptoms across multiple organ systems.

MCAS drives chronic multi-system inflammation and allergy and affects the skin, gastrointestinal, cardiovascular, respiratory, and neurologic systems; it is often a component of pain syndromes.

Most patients present with decades of chronic multisystem comorbid symptoms that are either inflammatory and or allergic in nature.

A mast cell is a type of white blood cell known as a mastocyte that contains a lot of histamine and heparin and thus plays a large role in allergies and anaphylactic reactions.

This key player in the immune system is also involved with pathogenic defense, wound healing, inflammation and blood-brain-barrier function.

Histamine is a neurotransmitter that is released by cells as part of an allergic response or as a response to injury.

A histamine release typically causes symptoms such as:

  • Rashes
  • Itching
  • Swelling
  • Stuffy nose

However, in MCAS these and other symptoms (see below) can often be chronic and more severe in nature.

Symptoms of Mast Cell Activation

Mast cells do not just release histamine; instead, they release their contents into surrounding tissues, causing symptoms when chronically activated such as:

  • Swelling of the throat or tongue
  • Itchy rash
  • Itchy throat
  • Swelling of the eyes
  • Vomiting
  • Shortness of breath
  • Low blood pressure (hypotension)
  • Lightheadedness
  • Hives
  • Itchy skin
  • Dermatographia
  • Pruritus
  • Flushing
  • Acid reflux
  • Bloating
  • Loose stools
  • Joint pains
  • Runny nose after meals
  • Headaches
  • Brain fog
  • Palpitations
  • Blood sugar instability
  • Painful urination
  • Increased urinary frequency
  • Irritability
  • Concentration problems
  • Memory loss
  • Neuropsychiatric issues
  • Fatigue

Common Mast Cell Triggers

Mast-cell activation can look like a histamine intolerance, but with a mast cell activation, there are many more triggers for activation than happens with a histamine intolerance.

Potential triggers of mast cell activation are:

  • Emotional stress
  • Temperature changes
  • Pollution
  • Mold
  • Mycotoxins
  • Pollen
  • Dander
  • Fatigue
  • Odors
  • Venom
  • Viruses
  • Bacteria
  • Fungi
  • Sunlight
  • Certain foods
  • Alcohol
  • Medications
  • Parasites
  • EMF
  • Metals
  • Pesticides
  • BPA and other toxins
  • Hormones

MCAS symptoms may flare during common allergy months in both the spring and fall.

Researchers have discovered that allergic, environmental and emotional stress can result in brain mast cell activation, which can lead to a focal disruption of the blood-brain barrier, neuroinflammation and seizures.

In addition, once the blood-brain barrier is breached, pathogenic infections can cross into the brain and lead to conditions such as Lyme disease, PANS, PANDAS, autoimmune encephalitis as well as potentially to neurodevelopmental conditions such as autism, ADHD and Sensory Processing Disorder.

The takeaway from this is that if your child has allergies, eczema, asthma, an autoimmune disorder or other type of chronic inflammation, they may be vulnerable to an onset of these disorders due to Mast Cell Activation Syndrome.

Link to Infections

Because mast cells play a key role in the defense system against pathogens, people with chronic infections such as Lyme disease, Bartonella, herpetic viral infections, PANS and PANDAS may develop MCAS.

In many of these cases, these infections are undiagnosed and untreated, thus leading to chronic mast cell activation.

However, if symptoms do not resolve with the treatment of inflammation and infection, then digging into mast cell issues may be the next step in improving health.

What to Do

Eat a Low-Histamine Diet

Children with mast cell activation or histamine intolerance can benefit from a low-histamine diet; high levels of histamines are found in foods such as:

  • Fermented foods such as:
    • Sauerkraut
    • Kim chee
    • Pickled vegetables
  • Aged cheeses
  • Most yogurt
  • Buttermilk
  • Processed, cured or smoked meats
  • Soy sauce and tamari
  • Vinegar
  • Beer
  • Wine
  • Other foods
  • Leftover foods

Once histamine is created in leftovers, it cannot be destroyed.

Although a low-histamine diet can help many, others may need to refine their diet by also adding in:

Eat a Ketogenic Diet

Tania Dempsey MD noted that many of her patients tend to do better on a ketogenic diet rather than a low-histamine diet.

Because a ketogenic diet removes all sugar and refined carbohydrates from the diet, it does an excellent job at stabilizing blood sugar, cortisol and inflammation.

Detoxify the Liver

A properly functioning liver is necessary for the breakdown of histamine; therefore, a poorly functioning liver may lead to a longer occurrence of histamine-related symptoms.

Heal the Gut

Healing the gut and improving liver function generally help with reducing histamine and inflammatory responses.

In addition, a healed gut is one that is not chronically constipated and thus allows toxins processed by the liver to be quickly eliminated from the body.

Take Certain Supplements

Your healthcare practitioner may recommend any of the following supplements to help with symptoms:

  • Luteolin
  • Quercetin
  • Holy basil
  • Curcumin
  • Homeopathic histamine
  • Hesperidin
  • Ellagic acid
  • Pomegranate

Be sure to consult a healthcare practitioner to see if any of these supplements are the right fit for your child.


Sources & References

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Afrin, L.B., et al. Mast cell activation disease: An underappreciated cause of neurologic and psychiatric symptoms and diseases. Brain Behav Immun. 2015;50:314–321. doi:10.1016/j.bbi.2015.07.002.

Campbell, et al. Mechanisms of Allergic Disease – Environmental and genetic determinants for the development of allergy. Clin Exp Allergy. 2015

Della Giustina, A., et al.. Vitamin D, allergies and asthma: focus on pediatric patients. World Allergy Organ J. 2014;7(1):27

Feehley, T., et al. Healthy infants harbor intestinal bacteria that protect against food allergy. Nature Medicine. 2019 Jan 14.

Frieri, M. Mast Cell Activation Syndrome. Clin Rev Allergy Immunol. 2018;54(3):353–365. doi:10.1007/s12016-015-8487-6.

Frieri, M., et al. Mast cell activation syndrome: a review. Curr Allergy Asthma Rep. 2013;13(1):27–32. doi:10.1007/s11882-012-0322-z.

Gupta, R.S., et al. The Public Health Impact of Parent-Reported Childhood Food Allergies in the United States. Pediatrics. 2018 Dec;142(6). pii: e20181235.

Hamilton, M.J. Nonclonal Mast Cell Activation Syndrome: A Growing Body of Evidence. Immunol Allergy Clin North Am. 2018;38(3):469–481. doi:10.1016/j.iac.2018.04.002.

Ly, N.P., et al. Gut microbiota, probiotics, and vitamin D: interrelated exposures influencing allergy, asthma, and obesity? J Allergy Clin Immunol. 2011;127(5):1087-94; quiz 95-6

Maksimova, O.V., et al. [Intestine microbiota and allergic diseases]. Zh Mikrobiol Epidemiol Immunobiol. 2014(3):49-60.

Petra, A.I., et al. Spectrum of mast cell activation disorders. Expert Rev Clin Immunol. 2014;10(6):729–739. doi:10.1586/1744666X.2014.906302

Prescott, S.L. Early-life environmental determinants of allergic diseases and the wider pandemic of inflammatory noncommunicable diseases. J Allergy Clin Immunol. 2013;131(1):23-30

Theoharides, T.C., et al. Neuro-inflammation, blood-brain barrier, seizures and autism. J Neuroinflammation 8, 168 (2011) doi:10.1186/1742-2094-8-168.

Tsabouri, S., et al. Modulation of gut microbiota downregulates the development of food allergy in infancy. Allergol Immunopathol (Madr). 2014;42(1):69-77.

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