Diagnosing Mast Cell Activation Syndrome

By Dr. Lawrence Afrin - a pioneer in the field

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    A laymen's summary of "Mast cell activation disease: a concise practical guide for diagnostic workup and therapeutic options." Gerhard J Molderings, Stefan Brettner, Jürgen Homann and Lawrence B Afrin. Journal of Hematology & Oncology 20114:10


    The diagnosis is met if both the major criteria or the second of the major criteria (symptoms) and at least one minor criterion are fulfilled


    Signs and Symptoms

    Symptoms often present in a variable and fluctuating pattern which depends on where the mast cells are being activated.

    Mast cell activation has been found in diopathic anaphylaxis nterstitial cystitis, some subsets of fibromyalgia, chronic fatigue syndrome (ME/CFS), postural orthostatic tachycardia syndrome (POTS), irritable bowel syndrome and others.

    MCAD or MCAS is usually first suspected when symptoms appear. The clinical presentation of MCAD, however, is very diverse with symptoms potentially occurring in virtually any place in the body. Plus, symptoms often wax and wane over the years. They often first show up during childhood but are recognized as such only later.

    Initially most patients enjoy symptom-free periods but over time the symptom-free intervals often lessen and the symptoms become chronic with fluctuations of increasing intensity.

    The disease progression is generally heterogenous as well; the disease can remain mild producing no effects on life expectancy and range to the very aggressive with increased mortality.

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    Physical examination should look for a large assortment of skin lesions, testing for dermatographism (Darier's sign), and checking for enlarged liver, spleen and/or lymph nodes.

    Other tests include elevated blood levels of tryptase, histamine, and heparin, increased levels of urine methylhistamine and whether blood eosinophilia, basophilia or monocytosis is present.

    Other possible markers include: serum chromogranin A (in the absence of cardiac and renal failure, neuroendocrine cancer, and proton pump inhibitor use) and serum and urinary leukotriene and prostaglandin isoforms (e.g., leukotriene E4, prostaglandin D2, and prostaglandin 9α,11βPGF2).

    Testing, however, may not be adequate as many conditions may prevent mast cell markers from spilling over into the blood and commercial testing can only detect a handful of most mast cell mediators.

    Diagnostic Algorithm


    After a clinical diagnosis, a bone marrow biopsy is usually recommended...Check out the journal article for more on diagnosis and treatment.


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