 |
| The proposed relationship between POTS and MCAD. |
What are Mast Cells?
Mast cells are cells of the immune system that are found around blood vessels in the skin, gastrointestinal tract, respiratory tract, and genitourinary tract, and are highly associated with nerves. They release chemicals including histamine that are very irritating and cause itching, swelling, and fluid leakage from cells.
"Mast cells are known to be the primary responders in allergic reactions, orchestrating strong responses to minute amounts of allergens. Several recent observations indicate that they may also have a key role in coordinating the early phases of autoimmune diseases, particularly those involving auto-antibodies."
What is MCAD?
As desribed technically, "Mast cell activation disease comprises disorders characterized by accumulation of genetically altered mast cells and/or abnormal release of these cells' mediators, affecting functions in potentially every organ system, often without causing abnormalities in routine laboratory or radiologic testing. In most cases of mast cell activation disease, diagnosis is possible by relatively non-invasive investigation. Effective therapy often consists simply of antihistamines and mast cell membrane-stabilising compounds supplemented with medications targeted at specific symptoms and complications. 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."
What does that mean? In simpler terms - MCAD is a collection of hard to diagnose (because they often don't show up in standard blood work) conditions related to "mast cells behaving badly." Mast cells are almost everywhere in the body. When they break down, it is called degranulation, and in MCAD the mast cells do this in a seemingly random way; releasing histamine that the body reacts to, causing all kinds of skin reactions, anaphylaxis (throat closing/itching/blood pressure drops, etc...), and even causing heart rate fluctuations and shortness of breath in some.
MCAD is also called MCA, or MCAS (the "S" stands for syndrome), and the current definitions by the WHO (World Health Organization) are being debated. Currently because of the WHO definitions of MCAD, it is very hard to get a solid diagnosis, and it is an under-diagnosed and misunderstood condition by many physicians.
