Please take a look at this newly published peer-reviewed article by Dr. Lawrence Afrin of which I was a co-author, on the revised criteria for the diagnosis of mast cell activation syndrome (MCAS):

Diagnosis of mast cell activation syndrome: a global “consensus-2”

One of the most common difficulties patients seem to face after they have been to our clinic and given a diagnosis of mast cell activation syndrome is when they return to their GP’s or specialists with a description of this syndrome. Traditional medicine is well-schooled in the diagnosis of systemic mastocytosis, a condition characterized by an increased number of mast cells as opposed to MCAS which is a diagnosis arrived at due to the increased activity of mast cells (and not an increase in the actual numbers).

Systemic mastocytosis is most often diagnosed by using a biomarker called tryptase, whereas the diagnosis of MCAS has much broader diagnostic criteria as this article will outline.

For a much more in-depth description of MCAS, please see my treatment page and the following articles:

1. Treating Mast Cell Activation Syndrome (MCAS)
2. Mast Cell Activation Syndrome: When You Immune System Runs Rampant
3. Natural Treatments For Mast Cell Activation Syndrome
4. Your Ultimate Guide to the Low-Histamine Diet