Mast Cell Activation Disorder- What you Should Know

Allergy season is here! And these are just the seasonal allergies. Did you know that many of us suffer from allergies all year long? They don’t always present with the same seasonal allergy symptoms of runny nose, sore throat and watery eyes. These allergies may present as rashes, gastrointestinal distress or even psychiatric complaints. They are caused by a similar mechanism to the traditional seasonal allergy with an elevation if histamine in our system.

Histamine intolerance is a growing phrase used in the integrative health care community. Everyone has histamine in their body, however some people are more sensitive to it than others. Histamine intolerance describes a presentation of worsening symptoms with food intolerances or other elevations of histamine levels. Typically, an excess of histamine is the true cause of these symptoms opposed to an intolerance. The question then arises, why is there an excess of this histamine? There is growing awareness in the medical community of a disorder that causes elevations of histamine and other chemicals in the body. This is known as Mast Cell Activation Disorder (MCAD). Mast cells are a type of immune cell that are supposed to be activated as a protective response to detect and respond to triggers of internal or external stress or danger.  The issue arises when they become disordered, or malfunction. This article will serve as a brief introduction to MCAD.

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"Mast cells are essential protectors or the body, but when they become over produced or over stimulated they can release toxic chemicals that increase inflammation in the body."

MAST CELLS: The “do-it-all” Immune cell

​Mast cells are white blood cells found in all parts of the human body. They are prevalent in areas where the body interfaces with the environment, including the GI tract, and skin. Mast cells are complicated and really are the “do-it-all” Immune cells. They are known for their role in allergies, but they also serve a purpose in wound healing, formation of are blood cells and maintenance of blood-brain barrier function.

Mast cells are always on the lookout for invaders to the body. They respond to numerous different triggers including various immune markers, microbial components, drugs, hormones, environmental exposures, and emotional stimuli. They also perform many different actions of the immune system. When they are triggered by any of the various stimuli listed above they “degranulate,” meaning they release certain chemicals into the body. These chemicals generally promote inflammation to protect the body. However, as previously discussed when the process goes awry that inflammation can be disproportionate to what is needed. This can happen in 2 ways. 1) The cells are over produced. 2) The activation is out of proportion with the need to defend the body.

The symptoms of MCAD vary greatly based on what substrates are released in excess or what the individual can tolerate. Mast cells can release over 200 different chemicals. Most prevalent are: prostaglandins, leukotrienes, tryptase and histamine. All of these serve important physiological functions in the body. For example, histamine regulates stomach acid secretion and plays a role in the systemic immune response. This issue arises when these mechanisms are left unchecked and can wreak havoc on the body.

Could You Have MCAD?

As previously discussed Mast cells are essential protectors or the body, but when they become over produced or over stimulated they can release toxic chemicals that increase inflammation in the body. So, what are the symptoms that occur when the system becomes disordered?

The typical presentation of MCAD is a chronic allergic or inflammatory response. As mast cells are present in every part of the body MCAD can that can affect any organ system. Some people complain of rashes, unexplained anaphylaxis, irritable bowel syndrome, depression, psychiatric, or chronic neurologic symptoms.

Due to the varied symptoms, degree of degranulation, and numerous chemicals released during degranulation it can be hard to diagnose MCAD with a diagnostic test. This is way a clinical diagnosis (diagnosis made by a clinician based on presentation and physical examination) is so crucial. It is not recommended to measure histamine as it is not accurate or specific to MCAD. The current diagnostic criteria include measurement of tryptase, one of the chemicals released with degranulation. The marker must be drawn 1) When the patient is not having any symptoms 2) Within 4 hours of a reaction. The clinician uses this information to establish a significant increase from baseline to make the diagnosis of MCAD.

"The typical presentation of MCAD is a chronic allergic or inflammatory response. As mast cells are present in every part of the body, MCAD can that can affect any organ system."

Mast Cell Activation Disorder: The Root Cause

There are some factors that may make one person more susceptible to developing MCAD than another. This could be excessive histamine production, a deficiency in diamine oxidase (DAO), HMNT mutation, poor methylation, or other environmental factors. A genetic predisposition does exist in some cases of MCAD. This means that if someone in your family has been diagnosed you are more likely to have it as well. The genetic predisposition comes from a point mutation (a single change on a chromosome). This results in overactive degranulation of these mast cells.

An environmental factor that weighs heavily into the development of MCAD is heavy metal toxicity. Heavy metals like mercury and aluminum are prevalent in our society. They are used in everyday products, dental amalgams, and vaccines. Heavy metals have a powerful ability to elicit a heightened inflammatory immune response, that is why they are used in vaccines. They are known to destabilize mast cells, and thus serve as a real issue in people with MCAD.

Another possible cause of MCAD is an active infection. This can be from parasitic, bacterial, viral or fungal infections. Since mast cells are on the lookout for intruders if there is a chronic infection that is untreated these mast cells are constantly being activated and releasing chemicals into the body. Unfortunately the immune system is no match for some of these infections leading to continual degranulation of mast cells with little change in the infectious process.  

With just about everything in functional medicine another serious complicating factor is gut dysbiosis. The gastrointestinal tract is home to about 70% of the immune system and a large number of mast cells. Any imbalance in the tract can cause stimulation of these mast cells and activate MCAD.

What you can do about MCAD

So now that we have gone through an overview of what MCAD is and the possible root causes, what can you do today to help the symptoms?
1) Pharmacologic agents that can block the action of mast cells may be necessary in the short term, but for a prolonged period of time there can be a significant deleterious effect on the homeostasis of the body. Remember mast cells are not bad, but if they are disordered they can cause undesirable symptoms.
2) An elimination diet or low-histamine diet to help reduce triggers (watch out for our upcoming blog post!)
3) Increasing nutrients that are known to stabilize mast cells in the diet. These include selenium, and vitamin C. There are a few herbals that also can stabilize mast cells like holy basil, turmeric and quercetin.
4) Supplementation with DAO: This is an enzyme made by the body that helps to break down histamine. Supplementation with additional DAO can be very beneficial for those with MCAD. This is really only a temporary treatment as it only decreases the histamine that comes from outside the body, not the histamine that is released from the mast cells.
5) Stress reduction.
6) Sleep. Sleep is restorative and is crucial to the body’s ability to maintain proper function.  
7) Remove heavy metals from the body: This should be done under the supervision of a medical professional. In general removal of any metal in the body is recommended, particularly mercury amalgams.
8) Treat chronic infections: This is why evaluation by a medical professional is essential.
9) Heal your gut: A diet high in whole foods, that is gluten free, dairy free and sugar free is recommended. Supplementation with a high-quality probiotic that will not increase histamine may be beneficial. However, some probiotics increase histamine, so consult your functional medicine practitioner prior to use. 

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Cortney Katz PA-C, CFMP

Cortney has a background in Internal Medicine with training and certification in Functional Medicine. She is versed in conventional and integrative therapies allowing for a diverse practice that focuses restoring the body to optimal functioning!