Mast cell activation syndrome

Mast cell activation disorder (MCAD) is a disorder where mast cells are normal in number but over-responsive to dietary and environmental triggers. Cells release excess histamine and other signaling molecules, causing symptoms. It can affect almost any organ system in the body, leading to misdiagnosis. The symptoms can be very similar to CFS/ME and MCAS can also coexist with it, complicating things further.

Symptoms
A confounding element in diagnosing MCAD or MCAS (the disease of mast cell activation is known as both a disorder and a syndrome) is that symptoms occur in almost all areas of the body, and tend to wax and wane and disappear and reappear. One patient may have ongoing daily episodes of anaphylaxis, while another patient may simply experience years of insomnia and low appetite. Symptoms do tend to respond to some sort of "trigger," which can range from a food to an environmental trigger to stress.

Anaphylaxis does not need to be the typical presentation of swelling throat; anaphylaxis can also present as a sense of "impending doom" and gastrointestinal distress. Mast cell activation syndrome also often appears with skin presentations - chronic urticaria (hives) is the main one, but some patients have otherwise unexplained psoriasis, eczema, sores and swelling.

MCAS often coexists with malabsorption problems, leading to low iron and low Vitamin D and low b12, which can cause extreme fatigue.

An exhaustive list of symptoms would include almost every symptom a person can have, but the main ones seem to be:


 * dizziness;
 * brain fog;
 * fatigue;
 * loss of appetite;
 * swelling in tongue/face/throat;
 * difficulty swallowing;
 * difficulty remembering words - different from brain fog, this is a sudden-onset of cognitive decline;
 * diarrhea/IBS;
 * shaking;
 * full anaphylaxis;
 * insomnia;
 * restless sleep;
 * unrefreshing sleep;
 * skin issues - hives, etc;
 * general feeling of unwellness

Dr. Lawrence Afrin has reported dozens of possible, seemingly non-allergic symptoms, including many hematological conditions and even osteosclerosis, a disease of bone.

Diagnosis
MCAS is difficult to diagnose with testing as the patient must be caught in a flare of enough severity and duration to be caught by a blood or urine test. A standard test is serum tryptase. If elevated >20, this indicates mastocytosis rather than MCAS/MCAD. It is important to test tryptase at baseline and again in a flare - if there is an elevation of more than 2 points, this tends to indicate positive diagnosis. A 24hr urine test, chilled, is also collected for testing and prostaglandin and histamine can be tested. Tests are often negative; a more important diagnostic process is the patient's story and possible response to a therapeutic trial of antihistamines and mast cell stabilizers.

Comorbidities
MCAD is often found in patients with Ehlers-Danlos syndrome (EDS) and postural orthostatic tachycardia syndrome (POTS), a form of orthostatic intolerance, two conditions commonly co-morbid with ME/CFS. The overlap between EDS, POTS, and MCAD is thought to be due to increased tryptase production owing to an extra copy of a gene called TPSAB1.

It has been implicated in many other immunological diseases including autism, fibromyalgia, and chronic Lyme disease.

Common treatments
Over the counter antihistamines such as Allegra and Zyrtec and Claritin are a common treatment for MCAD. Some patients also use herbal antihistamines and supplements such as quercetin and diamine oxidase (DAO), an enzyme normally produced by the body that breaks down histamine. Vitamin C, which reduces blood histamine levels, may also be helpful along with magnesium, a cofactor for producing DAO.

Dr. Afrin highly recommends sodium cromolyn in compounded oral form, as well as the use of the anthistamine and mast cell stabilizer ketotifen. Both of those medications are available over the counter only as eye drops and must be specially requested from pharmacies. Other antihistamines include hydroxyzine and levocetirizine. Many patients have also found the moderate use of benzodiazepines like lorazepam to be effective.

Experimental treatments
There is some limited evidence that sauna may be useful in antihistamine resistant urticaria, an allergic skin condition that involves mast cell activation and the production of excess histamine.

Omalizumab has been proposed as a possible mast cell stabilizer and is used in allergic asthma and chronic urticaria.

Doctors
There are a very few mast cell specialists working in the United States. An expert is Dr. Lawrence Afrin formerly at the University of Minnesota now in in Armonk, NY. Drs Clem Akin and Mariana Castells run a mastocytosis clinic at Brigham and Women's in Boston but their focus is on mast cell disorders as opposed to mast cell activation disorders. More integrative doctors are beginning to be aware of mast cell activation syndrome, but it remains elusive in both treatment and diagnosis.

Triggers
Emotional or physical stress, many foods, and environmental factors can trigger mast cell degranulation.

Food triggers
There are many food lists detailing common triggers but individual reactions will vary. Some individuals will react to all foods while others only to some.

Some foods containing high levels of histamine include salmon, avocado, red wine, strawberries, raspberries, cherries, spinach, and leftovers (especially fish and meat). Anything aged or process will be high in histamine and should be avoided (processed meats, aged cheeses, 36-hour chicken bone broth, etc.)

Environmental triggers
Mold, air pollution, and car exhaust are common environmental triggers.

Learn more

 * Low Histamine Chef
 * Mast cell activation syndrome, Wikipedia
 * Molderings GJ, Brettner S, Homann J, Afrin LB. Mast cell activation disease: a concise practical guide for diagnostic workup and therapeutic options. Journal of Hematology & Oncology. 2011;4:10. doi:10.1186/1756-8722-4-10. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3069946/)