Mast Cell Activation Disorder (MCAD) (MCAS)

Uncategorized / Thursday, January 7th, 2016


Mast Cell Disorders Keith Berndtson, MD Diagnosis and Treatment
People with Mast Cell Activation Disorders experience a very diverse range of symptoms. The same as those experience by people with it's rare cousin Mastocytosis (Systemic). These symptoms effect multiple systems, can be physical and psychological, and often occur in clusters suggestive of syndromes related to fibromyalgia, and/or neurological illness and/or stress related disorders.   Many people diagnosed with fibromyalgia or related syndromes and conditions, may actually have a Mast Cell Activation Disorder (MCAD) as well.  I did! The hallmark of mast cell disease is allergic-type reaction to a variety of stimuli and substances. These can also occur to substances benign to most people, including scents, “hypoallergenic” materials, heat, sunlight and water. Some people experience anaphylactic reactions that require epinephrine.  
Mast cell activation disease is now appreciated to likely be considerably prevalent and thus should be considered routinely in the differential diagnosis of patients with chronic multisystem polymorbidity or patients in whom a definitively diagnosed major illness does not well account for the entirety of the patient's presentation.
A Mast Cell Activation Disorder (MCAD), is an "allergic like" condition, but not a true allergic condition. Mast Cells respond to threats and assaults from the environment and in the body (e.g. infections, injuries). People with Allergies and people with MCAD, experience unpleasant symptoms from exposures to things that do not bother others due to Mast Cell over responsiveness. Symptoms associated with allergies, are primarily caused by a release of too much histamine from the mast cells and are IgE immune mediated. Symptoms associated with MCAD are caused by the release of too much histamine, and other substances and chemicals, that cause inflammation, changes to the nervous system (sensitisations) and changes to core functions, necessary for backing up the mast cells effort to respond to, and annihilate threats. The changes to core functions, usually include the slowing down of functions like detoxification and digestion, so energy and resources can be deployed else where. This is fine if happening infrequently, but when happening frequently which is the case for many people with MCAD (particularly when more severe)  it can lead to poor nutrient absorption and suboptimal cellular health, gut issues, and a build up of substances (toxins, chemicals and metabolic byproducts), to levels, the mast cells consider as threatening to ones well being, and to levels that are actually sometimes "toxic". Essentially people with more severe MCAD are stuck on a loop that feeds into itself. This loop can actually be quite difficult to break.   This  loop is "theoretically"  thought to be  initiated by a trauma of some description (e.g. infection, toxicity, mould chemical, psychological, physical)  or a period of high stress, in people with a more vulnerable genetic profile. But nobody is absolutely certain of the cause.
The standard treatment includes the use of anti-histamines, or medications that have an anti-histamine effect e.g. antidepressants (if tolerated) Trigger exposure reduction.  The first step in treatment should be a consultation with your doctor, to ensure you do not have an infection or other medical condition that is contributing to your symptoms or causing them.  That can be medically treated quite easily. For people with less severe MCAD, the use of anti-histamines, or mast cell stabilising supplements is usually very effective. For people with more severe MCAD they are not.

The following is from

Diseases which should be considered as differential diagnoses of mast cell activation disease, since they may mimick or may be associated with mast cell activation (diagnostic procedure of choice in parentheses).

Endocrinologic disorders Diabetes mellitus (laboratory determination) Pancreatic endocrine tumours (gastrinoma, insulinoma, glucagonoma, somatostatinoma, VIPoma; laboratory determination, medical history) Porphyria (laboratory determination) Disorders of the thyroid gland (laboratory determination) Morbus Fabry (clinical picture, molecular genetic investigation)
Gastrointestinal disorders Helicobacter-positive gastritis (gastroscopy, biopsy) Infectious enteritis (stool examination) Eosinophilic gastroenteritis (endoscopy, biopsy) Parasitic infections (stool examination) Inflammatory bowel disease (endoscopy, biopsy) Celiac disease (endoscopy, biopsy, laboratory determination) Primary lactose intolerance (molecular genetic investigation) Microscopic colitis (endoscopy, biopsy) Amyloidosis (endoscopy, biopsy) Intestinal obstructions by adhesions, volvulus and other reasons (medical history, imaging methods, laparoscopy) Hepatitis (laboratory determination) Cholelithiasis (imaging methods) Hereditary hyperbilirubinemia (laboratory determination)

Immunological/neoplastic diseases Carcinoid tumour (medical history, laboratory determination) Pheochromocytoma (medical history, laboratory determination) Primary gastrointestinal allergy (medical history) Hypereosinophilic syndrome (laboratory determination) Hereditary angioedema (medical history, laboratory determination) Vasculitis (medical history, laboratory determination) Intestinal lymphoma (imaging methods)
Triggers for MCAD are very diverse.   While identifying individual triggers that are most problematic to you can be beneficial, (made easier by grouping symptoms of clusters together that are suggestive of syndromes), it is usually best to take a generalised approach to trigger exposure reduction, if you are experiencing a lot of symptoms on an ongoing basis. Once you do this, it will be much easier to identify the triggers that are most problematic to you, so you an focus more energy on managing these. Triggers include:- Foodstuff Things that drag on us - lack of sleep, stress, doing too much, not unhealthy diet overindulging in alcohol etc. Allergens - even though MCAD is not a true allergic condition. Indoor air pollutants Sensory stimuli like noise, electronics, fragrance, heat, cold and even movement Exercise - too much, too little Infections
People with MCAD can experience a very diverse range of symptoms, they differ from person to person, and can wax and wane on a day to day basis, depending on trigger exposures, and the route of exposure e.g.  whether they have been breathed in, applied to the skin, eaten or occurred in the body.   The following table is from
Signs and Symptoms  
Abdominal abdominal pain, intestinal cramping and bloating, diarrhea and/or obstipation, nausea, non-cardiac chest pain, Helicobacter pylori-negative gastritis, malabsorption

Oropharyngeal burning pain, aphthae

Respiratory cough, asthma-like symptoms, dyspnea, rhinitis, sinusitis

Ophthalmologic conjunctivitis, difficulty in focusing

Hepatic splenomegaly, hyperbilirubinemia, elevation of liver transaminases, hypercholesterolemia



Cardiovascular tachycardia, blood pressure irregularity (hypotension and/or hypertension), syncope, hot flush

Neuropsychiatric headache, neuropathic pain, polyneuropathy, decreased attention span, difficulty in concentration, forgetfulness, anxiety, sleeplessness, organic brain syndrome, vertigo, lightheadedness, tinnitus

Cutaneous urticaria pigmentosa, hives, efflorescences with/without pruritus, telangiectasia, flushing, angioedema

Abnormal bleeding  

Musculoskeletal muscle pain, osteoporosis/osteopenia, bone pain, migratory arthritis

Interstitial cystitis  

Constitutional fatigue, asthenia, fever, environmental sensitivities
MCAD and Fibromyalgia, CFS, Environmental Illness etc. .
MCAD and nervous system sensitisation (gut, peripheral, brain - central) seem to go together,so it is not surprising that central sensitivity syndromes like: Fibromyalgia, Chronic fatigue syndrome, multiple chemical sensitivity, post traumatic stress disorder, and more are compatible with an MCAD diagnosis, and that many people with these conditions respond to MCAD Treatment. Other Chronic illnesses that seem to be compatible with MCAD (according to include:  Lupus, Chronic Lyme Disease, Interstitial Cystitis, Multiple Sclerosis, and more .
References ThePresentation MCAS

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