

Photo is of a mild MCAS reaction while on an anti-mediator regimen. It shows flushing/rash on the face and chest
If you know me personally, you probably know that I have a lot of “allergies” and sensitivities to foods, medications, and environmental agents (grass, pollen, detergents etc…). My reactions range from increased severity of migraine, to GI distress, to hives/anaphylaxis. What you likely don’t know is that don’t have any IgE-mediated (traditional) allergies at all, and my reactions to each of things I avoid is unpredictable each time I encounter them. This stumped allergists until recently, when I was diagnosed with Mast Cell Activation Syndrome (MCAS), also sometimes called Mast Cell Activation Disorder (MCAD), and a member of the broader family of Mast Cell Disorders.
What are Mast Cell Disorders?
Mast Cell Disorders are a group of conditions caused by overproduction or dysfunction of the mast cells. Mast cells are produced in the bone marrow and reside in connective tissues throughout the body (skin, lining of the digestive tract and airway, etc…). In healthy bodies, these cells play a part in immune defense and wound healing. They are also the cells that respond by releasing “mediators” such as tryptase and histamine during an allergic reaction that then cause inflammation in conditions such as allergic asthma, allergic rhinitis, and allergic anaphylaxis. In mastocytosis, the body overproduces mast cells and they accumulate in one or more organ system. In MCAS, there are a normal number of mast cells that overreact to triggers in the environment and release mediators that cause inflammation. The reactions can range from unpleasant to life threatening in severity. MCAS is more common than mastocytosis, but also a much newer diagnosis.
What are the symptoms of Mast Cell Disorders?
Mast cell disorders usually present with some but not necessarily all of the following symptoms: flushing, dermatographia (lightly scratching the skin allows you to “write” on it because it turns red), itching, skin rashes, hives, fatigue, headache, difficulty concentrating, nausea, acid reflux, abdominal pain, vomiting, constipation/diarrhea, musculo-skeletal pain, difficulty breathing, difficulty swallowing, coughing and chest tightness.
Some diagnoses that may be signs of mast cell activation include: idiopathic urticaria (hives), idiopathic anaphylaxis, non-allergic rhinitis, non-allergic asthma, Irritable Bowel Syndrome (IBS), acid reflux (GERD), eczema, multiple chemical sensitivity, histamine intolerance, autonomic dysfunction, psoriasis, Chronic Fatigue Syndrome/ME and Fibromyalgia.
How do they relate to EDS & Dysautonomia?
MCAS (and less frequently mastocytosis) are commonly seen alongside hereditary hypermobile connective tissue disorders (such as EDS), as well as in patients who have POTS (Post Orthostatic Tachycardia Syndrome) or other forms autonomic dysfunction. The presence of all three disorders in one person (such as myself) is frequent enough that this tricky trifecta of conditions is being studied by multiple researchers – some of whom believe that EDS causes POTS/Dysautonomia and MCAS, others believe that the autonomic dysfunction is the root problem, and still others believe that the mast cells themselves are the link between the three conditions. Dr. Milner, a researcher at NIH has found one gene that links all three conditions in some patients – he calls this condition Familial Tryptasemia. While doctors work to determine the causality of the relationship between these illnesses (which will hopefully lead to improved treatment options) it is safe to assume that if you have one or two of these conditions and have symptoms of another, they should be evaluated by physician who is familiar with the illness in question.
How are Mast Cell Disorders Diagnosed?
Mast Cell disorders are difficult to diagnose, because the labs and biopsies that are required are finicky. They must be taken during a flare, and they must be handled properly. Mastocytosis is usually diagnosed via bone marrow biopsy, although skin and GI biopsies may also be useful. Tests used to diagnose MCAS include:
- Serum Tryptase within a 2 hr window after reaction (blood test)
- 24 HR urine test to look for histamine and prostaglandin levels (This test frequently results in a false negative because either the patient or the lab did not refrigerate the sample properly – it must be kept cold at all times)
- Response to an anti-mediator regimen
Because these tests are so finicky, a clinical diagnosis of Mast Cell Activation Syndrome may be made in the absence of positive tests, if there has been an effort to rule out other possible causes, there is a history of mast cell activation symptoms, and significant improvement is made on an anti-mediator treatment regimen, and the patient is continually evaluated/followed by an allergist or mast cell specialist. This is how I was diagnosed.
How are Mast Cell Disorders Treated?
Treatment is dependent on specific symptoms, and their severity but usually includes an anti-mediator regimen to stabilize mast cells. These usually include various antihistamines (H1 and H2 blockers). For example, my regimen includes Zyrtec, Zantac, and Singulair. Different people have success with different medications though, and the regimen should be developed and tweaked by an allergist or mast cell specialist. People with MCAS may also need to carry an EpiPen or an epinephrine auto injector. If asthma or restrictive airway is a part of the condition for a particular individual, then it should also be treated. Some people with MCAS also find relief by using a low histamine diet and/or by using an elimination diet to identify specific food triggers.
Sources:
- The Mastocytosis Society: Mast Cell Disorders. (2017). Retrieved February 10, 2017, from http://tmsforacure.org/
- Mast Cell Aware. (2016). Retrieved February 10, 2017, from http://mastcellaware.com/
- Horowitz, K. (2016, October 17). One Gene Mutation Links Three Mysterious, Debilitating Diseases. Retrieved February 9, 2017, from http://mentalfloss.com/article/87506/one-gene-mutation-links-three-mysterious-debilitating-diseases
I have been diagnosed with EDS hypermobility and Mast Cell Activation Disorder. I have all the signs of dysautonomia, too. I hope researchers can find a way to improve treatment, because the 3 drugs aren’t helping me too much. Thanks for sharing this information 🙂
I hope they do as well, but there are quite a few medication options out there, talk with your allergist about switching it up if you can! Personally, I’ve been able to curb all of my skin symptoms and breathing symptoms. The GI and migraine are a little more complex – there are other contributing factors!
Hi there, what are you given fit the breathing difficulties? I’m really struggling with this condition and currently housebound
Hi! I am currently struggling more than when I wrote this post and am about to meet with my allergist to revise my treatment plan. That said for breathing in addition to H1 & H2 blockers I currently take singulair & aerospan, and use ProAir HFA as a rescue inhaler
Thank you for all you do my daughter has EDS and dysautonomia and it is making her life miserable.
I suffer from EDS, PoTS and possibly this as I have lots of drug reactions, GI problems, skin problems. Not diagnosed yet as not sure who I need to see. They are really hard conditions to manage and more medical people should be educated on them.
Thank you so much for participating in our first link up party at The Unbroken Smile. Your article is so informative, thank you! I’m sure our readers will enjoy it. ((Gentle Hugs))
– Elizabeth
When you say your reactions are unpredictable, do you mean the severity of a reaction or if you have one at all? Because I had a false positive on a 30 item skin prick test as a kid because everything reacted, and now i someTimes react to things like pineapple and banana (with skin tightening/slight swelling, numb lips and palate, and flushing) but sometimes I don’t react (or if I do it’s so mild i can’t tell ). I have EDS and possibly LOTS, but ?
Hi – I guess the answer would be both. When I have had skin prick tests I have reacted everything in some days and nothing on others. Sometimes I can eat a certain food and be fine, and other times I am sick almost immediately. Other foods are more more predictable and always elicit a reaction but the strength of the reaction varies. I hope that helps!
I have been searching everywhere for some source material linking all these conditions together, as I’ve been having a hell of a time getting my doctors to acknowledge this. Glad people at NIH are doing research to prove this correlation as I think it will make it easier on all of us to get the right care in a more timely manner.
Wow! This is a great article I just went to the allergist/immunologists who specializes in mast cell. He told me the same thing &diagnosed me with EDS too. I’m going to the geneticist to find out what kind of EDS I have. I’ve had Hyperpots &been diagnosed with ttt in 2015. This is very informative. Thank u this really helps us newbies understand what is going on. I hope they come up with a treatment plan for all of it that works better for us trifectas.
Hi I’m that bad with foods I can only eat apples Carr’s waters biscuits (other brands have raising agents in & I have had allergic reaction to them) fresh small pieces of cooked plain chicken water or black coffee & gluten free vitamin shakes to stop my hair falling out again. I get bad migraines all the time my face, mouth, tounge ,hands & throught swell with in minutes and it feels like someone has there hands round my neck.any thoughts I use so many episodes pens
Hi Hayley! I wish I had solid advice for you. MCAS is so tricky! And so many people like you struggle with it more severely than I do. I like the blog Mast Attack, written by a biologist who has mastocytosis for treatment ideas: http://www.mastattack.org/2014/10/mcas-treatment/
Thanks for the post. Very educational and enlightening.