What is Mast Cell Activation?

Mast Cell Activation Syndrome (MCAS) and Mast Cell Activation Disorder (what my docs call my disease) are within a spectrum of mast cell activation conditions.  I have this condition – it is not fun.  My diagnosis was verified through the three co-criteria requirement explained here.  I had to leave my state and go to Boston to get the diagnosis.  Not all patients are as fortunate as I am to have had access to these tests and doctors….

so I share the knowledge 🙂


What the heck is Mast Cell Activation anyway?  What does this have to do with EDS and pain?


Many EDS patients have intra-cellular motility/extracellular matrix issues and cellular membrane instability issues as a direct result of their collagen defect.  Yes, one small little defect in DNA regarding the use of collagen can effect something as little as HOW WELL THE CELL WALL OF A MAST CELL REMAINS TOGETHER.  Ultimately determining if your body gets flooded with vaso- constrictors (makes your veins get small!), histamine, prostaglandins and a bunch more systems-altering chemicals at seemingly little to no provocation.


What this means, basically, is the mast cell patient’s immune system is “on the fritz” and incorrectly identifies things in the environment as “bad” and treats them as such.  This results in allergic-type reactions as well as autoimmune reactions to things like SUNLIGHT, changes in temperature, etc.  It’s like having moderate and chronic anaphylaxis symptoms at all times.  It’s a tricky condition to manage.


For some EDS patients, like me, mast cell activation disorder triggers full body inflammation – popping out joints with the swelling, guts all inflamed, sinus problems, skin manifestations/rashes/hives, muscles inflamed and burning/weak (feel like they are filled with lactic acid), brain fog, bone pain, headaches, migraines… and then my autoimmune system starts attacking parts of my body (because I also have ulcerative colitis).   Since I also have postural orthostatic tachycardia syndrome (meaning my blood pressure drops to 80/50 and my heart rate doubles when standing for a few minutes) – the combination of a mast cell flare, EDS flare, and UC flare means I cannot stand up without passing out when all hell breaks loose in my body!


Here’s the details – from the professionals – on Mast Cell Activation Disorder/Mast Cell Activation Syndrome



Quoted from Ehlers-Danlos Society (link to full article):

Introduction: Mast Cells and Their Properties

Mast Cells (MCs) were first discovered in the late 19th century by German physician and scientist Paul Erlich. He saw a new type of cell from around blood vessels and connective tissue that appeared to have large granules inside. Erlich incorrectly believed that these cells fed others, so called them “Mastzellen” (German for “fattening cells”). Mast cells are actually part of the immune system, protecting the body from parasites and other things that shouldn’t be there.

MCs first develop from blood stem cells in the bone marrow, then change further depending on where in the body they end up. Unlike other immune cells it is normal for mature (fully changed) MCs to stay around the tissue they moved to (such as nerves and blood vessels). Mast cells work by being “activated” by things the body interprets as potentially harmful, the mast cells then release histamine and other molecules into the surrounding tissue to signal a response from the body, which leads to swelling, warmth, and redness (inflammation). MCs are best known for their role in allergic responses like asthma, food allergy, and anaphylaxis, but recent research suggests they may have a role in many non-allergic disorders.

Mast Cells, Connective Tissue, and Mast Cell Activation Disorder

Cells of the body are surrounded and supported by a network called the Extracellular Matrix (ECM), which can be made from structural materials like collagen. Structural materials like collagen play an important role in the connective tissue of the body generally, and are associated with the Ehlers-Danlos syndromes (EDS). MCs can stick to the ECM, which in turn alters their behavior. EDS, as a connective tissue disorder, could change the ECM enough to cause a change in MC behavior.


SOO, that’s the basics of mast cells and why this seems to happen a lot with folks with EDS.


NOWWWWW, let’s get to learn a little about these mast cells, eh? 

Here’s an up close and personal look at them provided by The Mastocytosis Society (link to full article):



Mast cells (MC) are immune system cells that live in the bone marrow and in body tissues, internal and external, such as the gastrointestinal tract, the lining of the airway, and the skin. Everyone has mast cells in their body, and they play many complex and critical roles in keeping us healthy. The positive roles that they play include protecting us from infection, and helping our body by participating in the inflammatory process. However, mast cells are also involved in allergic reactions, from the tiny swelling that appears after a mosquito bite to a life threatening, full-blown anaphylaxis.

Mast cells have within them small sacs, or granules, surrounded by membranes. The sacs contain many different kinds of substances called mediators, which participate in all of the roles above, including allergic response and anaphylaxis.

The mediators are selectively released when there is an allergic or mast cell based reaction.1

Figure 1. Mast cell (electron micrograph)


Provided by Mariana Castells, MD, PhD

There is a difference between someone who is healthy, with mast cells that are functioning normally, and someone with a mast cell disorder, whose mast cells may be activating inappropriately in response to triggers, or may also be proliferating and accumulating in organ tissues.


Mast cell disorders are caused by the proliferation and accumulation of genetically altered mast cells and/or the inappropriate release of mast cell mediators, creating symptoms in multiple organ systems.2The two major forms of mast cell disorders are mastocytosis and mast cell activation syndromes (MCAS). Mast cell disorders can cause tremendous suffering and disability due to symptomatology from daily mast cell mediator release, and/or symptoms arising from infiltration and accumulation of mast cells in major organ systems. Although systemic mastocytosis is a rare disease,3 those suffering with MCAS have recently been increasingly recognized and diagnosed. As a result, patients with MCAS appear to represent a growing proportion of the mast cell disorder patient population.4, 5 It is important to note that the process of mast cell activation can occur in anyone, even without a mast cell disorder, as well as in patients with both mastocytosis and MCAS.6



What kinds of things are INSIDE of mast cells?  WHAT CAN THEY DO TO A PERSON?

Well, mast cells release chemicals into the system… and then the system releases mediators.  It’s a ton of crap in your blood stream when your mast cells decide to respond to something as innocuous as sunlight as if it were an allergen or “bad”.    I am going to go ahead and quote The Mastocytosis Society again


(link to full article)

Mast Cell Mediator Symptoms

The myriad symptoms patients with mast cell disorders experience during mast cell activation can wreak havoc on patients on a daily basis, and multiple organ systems, including pulmonary, cardiovascular, dermatologic, gastrointestinal, musculoskeletal, and neurologic can be involved. Table 1 lists some potential effects linked to specific mediators.5-13 Symptoms (Table 2) may include, but are not limited to: flushing of the face, neck, and chest; headache; tachycardia and chest pain; abdominal pain, bloating, gastroesophageal reflux disease (GERD), diarrhea, vomiting; uterine cramps or bleeding; rashes, including maculopapular cutaneous mastocytosis (MPCM)/urticaria pigmentosa (UP), telangiectatic lesions; bone/muscle pain, osteosclerosis, osteopenia, osteoporosis; itching, +/- rash; blood pressure instability; brain fog, cognitive dysfunction; anxiety/depression; lightheadedness, syncope; and anaphylaxis. These symptoms may appear as acute (as in anaphylaxis, see Table 3) or as chronic conditions. It should be noted that the manifestation of anaphylaxis or similar symptoms among infants and preschoolers may be more difficult to identify.

Table 1. Possible Effects of Some Mast Cell Mediators13, 14

Histamine Flushing, itching, diarrhea, hypotension
Leukotrienes Shortness of breath
Prostaglandins Flushing, bone pain, brain fog, cramping
Tryptase Osteoporosis, skin lesions
Interleukins Fatigue, weight loss, enlarged lymph nodes
Heparin Osteoporosis, problems with clotting/bleeding
Tumor Necrosis Factor-α Fatigue, headaches, body aches

This list is by no means complete and serves as an example. Mast cells secrete many mediators responsible for numerous symptoms within different organ systems.


(Side note – I get a huge build up of TNF in my body which then triggers my autoimmune disease to start attacking my joints.  I have to get an anti-TNF agent infused every month or so in order to stop the fatigue, headaches, and body aches associated with my autoimmune disease flaring in response to too much mast cell activity!  You seeing how this is all connected yet?  🙂


Finally – WHAT THINGS TRIGGER MAST CELL ACTIVATION?  What does a person with MCAD/MCAS have to look out for in the world around them?

Mast Cell Activation and Triggers

Mast cells can be activated to release mediators by multiple triggers. Possible triggers of mediator release are shown below in Figure 1. Please note that any patient with a mast cell disorder can potentially react to any trigger, and triggers can change over the course of the disease. In addition, patients may experience reactions to virtually any medications, including medications that they have tolerated previously. Common medication reactions in mast cell disorder patients include, but are not limited to: opioids, antibiotics, NSAIDs, alcohol-containing medicines and intravenous vancomycin. Use with caution. More information related to drug hypersensitivity in mast cell disorders is available in a position paper by European specialists.1

Figure 1. Some Potential Mast Cell Triggers2-5

  • Heat, cold or sudden temperature changes
  • Stress: emotional, physical, including pain, or environmental (i.e., weather changes, pollution, pollen, pet dander, etc.)
  • Exercise
  • Fatigue
  • Food or beverages, including alcohol
  • Drugs (opioids, NSAIDs, antibiotics and some local anesthetics) and contrast dyes
  • Natural odors, chemical odors, perfumes and scents
  • Venoms (bee, wasp, mixed vespids, spiders, fire ants, jelly fish, snakes, biting insects, such as flies, mosquitos and fleas, etc.)
  • Infections (viral, bacterial or fungal)
  • Mechanical irritation, friction, vibration
  • Sun/sunlight


Basically, your body becomes “allergic” to life.  There are things to help, however!  Anti-histamines that work at the different histamine receptors in the body, for example (link to medications for mast cell).

Trigger avoidance is KEY… but it is tricky!  You HAVE TO STAY PRESENT, BE AWARE OF YOUR BODY AND HOW IT INTERACTS WITH THE WORLD AROUND YOU in order to start managing this condition.  This is where the steps to managing pain and to stay present/focused come in handy 🙂


Mast Cell Activation/Mediator Release Symptoms

Controlling symptoms of mast cell activation/mediator release starts with avoiding the very triggers which we know will initiate mast cell activation in us, and the triggers can be very individual. Avoiding heat, cold, abrupt changes in temperature, sunlight, strong odors/perfumes and chemical smells can help many patients. Caution must be taken around venomous creatures such as bees, wasps, hornets, spiders, jellyfish and snakes, etc. Stress and fatigue can be major triggers for many patients, as can viruses, bacterial and fungal infections. Sometimes a simple change in routine can trigger us!

Many foods can trigger mast cells to activate and release their mediators; shellfish, peanuts, nuts, citrus, and high histamine foods are high on the list of potential triggers known to bother some people, but not others. Medications to be taken with caution include NSAIDs such as ibuprofen, toradol, aspirin (this can be confusing, because aspirin can also be used as a treatment for those with high prostaglandin levels; when used as a treatment it must be started under the supervision of a physician!), opioid narcotics, alcohol, the intravenous form of vancomycin (the oral form is usually fine), some anesthetics, some antibiotics, and topical agents, like benzocaine. However, everyone is different, and anyone can react to anythingand you can even react to something that you have never reacted to before, so always proceed with caution. Always have someone with you when taking a new medication, starting a new treatment, or traveling to a new place.

The most irritating thing can be that sometimes we do not even know what the trigger was that sent us into a mast cell frenzy! In that case, treat the symptoms, get some rest, and then review the last few days to see if you can spot a culprit. Also, remember that your response may be delayed. You may have an alcoholic drink on Saturday, and then be symptomatic several days later. Keeping a food, medicine and symptom diary can help you connect the dots!