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The Curious Case of Mast Cell Activation.

Posted in Personal Blog


So, what is a mast cell? “A mast cell (also known as a mastocyte or a labrocyte) is a type of white blood cell. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems and contains many granules rich in histamine and heparin.” Wikipedia

I am prone to rashes, more recently a rash that waxes and wanes, flaring up to a point where it feels like tight deep burn. My daughter, who is currently studying mast cell reactions, looked at my rash and said that in her opinion it was caused by a mast cell reaction. My reply “oh?” whilst my mind raced wondering what on earth could have triggered the reaction.

Rash on face, both arms, chest & neck ~ around lips look like lips have bled out onto my skin

So the obvious and logical next step, after calling out to Facebook chums for their thoughts, was to fire up google and have a wee search. It appears that there are rather a few conditions/causes for such reactions, the list can be found here.

The website linked above also goes on to define what mast cells are;

“What Are Mast Cells?
Mast cells are “master regulators” of the immune system. They come from bone marrow and go into all tissues of the body. Each mast cell contains secretory granules (storage sacs), each containing powerful biologically active molecules called mediators. These can be secreted when mast cells are triggered, leading to allergic and inflammatory diseases.”

Which leads me to thinking my clever youngest daughter is right ~ somewhere along the line my compromised autoimmune system, thanks to ME, FMS & HEDS, has been triggered, causing the hives and swelling reactions on my body. Thing is ~ what was the trigger?

Having not eaten anything new, used any new laundry detergents or toiletries leaves me flummoxed. The only “new” thing is acrylic wool ~ I’m crocheting a blanket for youngest daughters bed and so have been using the wool. However, I used it for a full week prior to any reaction ~  so unsure as yet whether that is the culprit. Perhaps will only know for sure after the blanket is finished.

Taken from the same site again, is a great visual explaining the parts of the mast cells, I have created the links onto the descriptions if you want to read up more about each part.


Click the links to learn more about the parts of a mast cell. (Links open in new window)

1 Allergens & Triggers
2 Storage Granules
3 Mast Cell
4 IgE Antibodies
5 Histamine & Tryptase
6 Degranulation

In this illustration, the mast cell, similar in appearance to a white blood cell (white/blue areas), contains many storage granules (purple spheres) rich in histamine and tryptase (small orange granules).When allergens, drugs, toxins, etc. (green & pink spiked shapes) are binding & cross-bridging the antibodies (yellow Y-shaped pairs), a mast cell reaction is triggered, releasing histamine, tryptase and other mediators into the system (represented by the release of orange granules).

Thanks to Theoharis C. Theoharides, MS, PhD, MD, FAAAAI for his guidance with this visual interpretation of mast cells in activation.

As I googled I found many articles suggesting that having autoimmune disorders such as ME, FMS & HEDS often resulted in having mast cell reactions. An abstract from NCBI says this..

Mast cell (MC) activation disorders present with multiple symptoms including flushing, pruritus, hypotension, gastrointestinal complaints, irritability, headaches, concentration/memory loss and neuropsychiatric issues. These disorders are classified as: cutaneous and systemic mastocytosis with a c-kit mutation and clonal MC activation disorder, allergies, urticarias and inflammatory disorders and mast cell activation syndrome (MCAS), idiopathic urticaria and angioedema. MCs are activated by IgE, but also by cytokines, environmental, food, infectious, drug and stress triggers, leading to secretion of multiple mediators. The symptom profile and comorbidities associated with these disorders, such as chronic fatigue syndrome and fibromyalgia, are confusing. We propose the use of the term ‘spectrum’ and highlight the main symptoms, useful diagnostic tests and treatment approaches.”

Another article which I found here, says..

“Mast cells can express different receptors and ligands on the cell surface, molecules that can activate the cells of the immune system, such as different subsets of T cells. All these mediators and cell surface molecules can promote inflammation in the skin. During the last years, a new role for mast cells has emerged; induction of tolerance or immunosuppression and interaction with regulatory T cells. However, the mechanisms that switch the proinflammatory function of mast cells to an immunosuppressive one are unknown.”

Fascinating stuff, so I googled further for more information available about how it affects those of us who are immune suppressed. I stumbled upon this, published in Prohealth..

“Mast Cell Activation Syndrome is new to the medical profession – much newer than ME/CFS or FM. Diagnostic criteria were only proposed about five years ago and because most doctors don’t know about it, it’s rarely diagnosed.”

The article continues (which I find very interesting)..

“It’s also often associated with POTS, Elhers Danlos Syndrome, Lyme Disease and ME/CFS/FM. Dr. Klimas has called it one of the most interesting immune diseases going.”

Which would explain why I am finding myself suffering from inexplicable waxing and waning rashes of different varieties. Unfortunately though I can’t find out why, what the trigger is and how to reduce the inflammation and duration of the rashes other than taking antihistamines. The following part of the article rings very true for me, the doctors call me their anomaly, they simply can’t figure me out and have no clue how to proceed. Instead just help me to “manage” symptoms as best they can.

“In fact, it can produce among the strangest and widest variety of symptoms of any disease. So many that the people afflicted with these kinds of allergies usually utterly baffle their doctors. Most doctors don’t know anything about them and they are rarely diagnosed. They’re caused by a disorder called Mast Cell Activation Syndrome (MCAS) which features mast cells gone a little crazy.”

 They further explain very clearly the role of mast cells in healthy people as being..

“mast cells are really common and really important. So much so that they’re often called the master regulators of the immune system. Mast cells come from the bone marrow and are filled with sacs of chemical mediators. Histamine is the most commonly known mediator, but there are countless others.

Mast cells also play an important role in the body’s first line of defense. Their signals recruit other players in the immune system response and help to keep us healthy and free from disease.”

The problem with diagnosing Mast Cell Activation Disorder (MCAD) is that many symptoms are the same as those for ME, FMS & HEDS ~ every singe cell in the body can be affected by mast cell activity which explains the huge and varied symptoms from cognitive dysfunction, to fatigue, digestive issues, blood issues and so on. Also, to make matters more complicated the MCAD can affect each individual differently so that there is no set clear pattern to it’s activities. There are tests it goes on to say, for MCAD, but not ones to be offered by GP’s but hospitals ~ also the tests may need to be repeated several times to gain a positive result ~ how often do doctors repeat and repeat tests? In my experience they don’t, test once and then leave it at that. So I suppose you are lucky if it shows positive first time of testing to gain diagnosis.

Then it moves onto treatments; which I will list but you can read more about each one here; Antihistamine drugs, mast cell stabilisers, trigger avoidance (Ha ~ easier said than done, how on earth do you determine what the trigger is?), diet ~ low histamine one, which you can read more about here, alteration of medications to ensure they are free from fillers and artificial colours.

ME Action UK published this about how sufferers of ME/CFS most likely have MCAD. I quote “Evidence has certainly been presented for a causal involvement of pathologically active mast cells in interstitial cystitis, fibromyalgia and irritable bowel syndrome (6) and a link is suggested with POTS and dysautonomia (7), all of which are frequent comorbidities with ME/CFS. Mast cell activation disorder (MCAD) can cause tremendous suffering and disability: there is no cure for it and management is directed towards symptom control.”

I have also discovered this article on Health Rising  which talks about histamine intolerance in sufferers of FMS and ME.  It gives us the histamine overview as this..

“Histamine is a potent signaling molecule or biogenic amine made from the amino acid histidine. It is naturally found in plants and animals. Histamine helps regulate many bodily functions including digestion, sleep, sexual function, and blood pressure, and in the brain it functions as a neurotransmitter, carrying chemical messages between nerve cells.

Under normal circumstances small amounts of histamine help to facilitate health and balance in many systems of the body. In response to foreign pathogens, wounds and allergies, however, large quantities of histamine are released in our bodies by mast cells and basophils – two types of white blood cells that reside in blood and tissues respectively. People with allergies often take antihistamine medications to provide relief of symptoms associated with this inflammatory response.

Histamine exerts its effects by binding to four different receptor sites on cells. Each site is able to produce different symptoms by impacting different tissues and organ systems.”

Then the article talks about histamine in our diet and how following a low histamine diet may help control symptoms of mast cell activation. Interestingly women who are perimenopausal and menopausal can often have histamine intolerance too. Holds up hand to being in the midst of perimenopausal drenching hot flushes!


Looking at the above graphic I am a sufferer of many of these symptoms ~ so am seriously going to look at changing to a low histamine diet to see if that helps improve my symptoms along with *crosses fingers* reduction of rashes too.


I found an article in Genetic Genie which also discusses the highly suspected MCAD in those who suffer from the immune suppressing conditions of ME, Fibro, Lupus and Lyme to name but a few.

The article says..

“Systemic mastocytosis (mas-to-sy-TOE-sis) is a disorder caused by a genetic mutation that results in an excessive number of mast cells in your body. Mast cells normally help protect you from disease and aid in wound healing by releasing substances such as histamine and leukotrienes. But if you have systemic mastocytosis, excess mast cells can build up in your skin, around blood vessels, in your respiratory, gastrointestinal and urinary tracts, or in reproductive organs. When triggered, these mast cells release substances that can overwhelm your body and result in symptoms such as facial flushing, itching, a rapid heartbeat, abdominal cramps, lightheadedness or even loss of consciousness. Common triggers include alcohol, temperature changes, spicy foods and certain medications. The following “triggers” may influence a mast cell response: drug abuse, excessive alcohol consumption, preservatives, stress, sunlight, environmental toxins, bacteria/fungi/mold, artificial colors or flavorings, heat/cold, etc. Minimizing your exposure to these triggers may help reduce your mastocytosis risk.”

The article also pointed to the NHS website for more information, which I will share with you here.

One last article I will share with you was found on the Kaiser Permanente Washington Health Research Institute website.

The article is about whether mast cells help to unlock chronic and unexplained disease. It says that..“Doctors know that mast cells are part of the immune system, but they might not know about MCAS, which was only recently recognized as one of two forms of mast cell activation disease. The better-known form, mastocytosis, is very rare and results from too many mast cells. In contrast, people with MCAS have a normal number of mast cells, but those cells behave badly. In addition to responding to common allergens, in MCAS the mast cells can be hyper-responsive to otherwise non-threatening stimuli, even foods, smells, and physical or emotional stressors. We don’t yet know how common MCAS is, but preliminary research suggests it may affect one in six people (~17 percent).”

The article goes on to say..

“Why is rogue mast cell activation bad?

“When activated, mast cells release many chemicals (such as histamine, heparin, leukotrienes, cytokines, and many others). These chemicals directly or indirectly cause a host of responses in the body including (but not limited to) inflammation, pain, and slow wound healing. Chronic inflammation is as an important underlying cause of chronic disease, since prolonged inflammation can damage the body and is even implicated in some neuropsychiatric illness. By constantly causing inflammation and other reactions in the body, chronic mast cell activation can wreak havoc. And because mast cells are located throughout the body, this havoc can appear just about anywhere.
What should providers know about MCAS?

If Dr. Afrin and his colleagues are correct, MCAS should always be suspected in people with poorly explained chronic, multisystem disease, particularly when allergic symptoms or inflammation are involved. Dr. Afrin’s book also nicely illustrates how frustrating this condition is for patients and providers because MCAS can look different in each person and a patient’s symptoms can change over time as different organ systems are affected. It appears that MCAS is more prevalent in females than males (3:1).

What does the future hold for MCAS?

In time, we will learn more about the underlying cause of MCAS (current thinking attributes it to one or more genetic mutations), how to effectively manage the disease, and perhaps even how to cure it. In the meantime, Dr. Afrin and his colleagues want to raise awareness of MCAS among the medical community and patients living with chronic disease. With this awareness will come the necessary funding, research, and knowledge needed to help us reduce the pain and suffering experienced by those living with chronic disease due to MCAS.”

I find all of this fascinating, since having children my body has changed enormously. I have low blood pressure (Orthostatic Intolerance) and during my middle pregnancy had gestational diabetes. The legacy of my pregnancies ~ other than my wonderful three daughters, who I am forever thankful for, has left me with allergies and poor health. I am now latex allergic, leather allergic, allergic to adhesives in plasters and tapes, allergic to paint fumes, am more sensitive to medications, so lower doses are to me the same as larger doses in “healthy” people. I am very slow to heal ~ my surgeon told me I take twice as long as I should to heal. I bleed more profusely ~ like someone on long term blood thinners. I suffer from unexplained rashes, have a permanent snuffly nose which never develops into a cold but also never goes. I have digestive issues along with the diverticulitis which means twice daily laxatives are needed permanently, plus acid reflux and heartburn. I have joint and muscle pains, weakness in ankles and wrists particularly ~ requiring splints and mobility aids. Hyper~mobile joints causing issues with my jaw and mobility. Regular headaches and body pains which pain killers don’t ease. These are only a few of my regular daily symptoms, but suffice it to say they make living different to how it used to be. On top of that I have sometimes severe, but usually just inconvenient, cognitive issues ~ this makes comprehending information difficult. It also makes word finding and word combining difficult for me. I often need to zone out to stop becoming too heavily overloaded, which can be awkward if mid conversation.

I am more grateful than ever before of how my body keeps me safe, it may not be perfect and is battered and bent due to weathering a number of storms. I now acknowledge that it works hard to protect me and it’s reactions are in turn responding to some trigger within spurning widely varied symptoms to manage within any one day. Reading about mast cell activation disorder/syndrome makes sense of all these symptoms, especially as I have a number of conditions which fall under the category of diseases affected by it.

I am now more at peace with the rashes as I can now understand that it is a body reaction to triggers which as yet I have not pinpointed. Although I do get them during stressful episodes ~ usually on my chest, which makes me self~conscious if my neck is visible. The current yo~yoing rash on my face, neck, chest and arms is uncomfortable, it feels like a burn, tender to touch and tight on my skin but prickling and itchy too. It also makes me feel self~concious from a vanity point of view.

I have found this blog post, which talks about histamine intolerance and advice regarding diet which I will read through a few times taking notes and try tweaking what I eat to see if anything changes for the better.

So that’s all for now on my voyage of discovery, I feel I have just scrapped off a very fine top layer of the topic and will be spending time and energy as and when I can looking into this in more depth. This will take time ~ all information needs reading, re~reading and reading again to lodge even slightly within my brain these days. Cognitive issues are hugely frustrating and so I know it’s going to be a long and gnarly journey. If I find anything beneficial in easing symptoms then I promise to share that with you.


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