It's called the IgG intolerance and shows up after 24h-72h of eating food that one doesn't tolerate. The difference between intolerance and allergy (IgE) is that allergy shows up immediately.
Our immune system is complex, IgE is just a tiny part of it. Some introductory reading:
MCAS = Mast Cell Activation Syndrome MCAD (Mast Cell Activation Disorder) = MCAS or mastocytosis
Good MCAS links here: http://strengthflexibilityhealtheds.com/2016/02/04/diagnosin...
http://www.mastattack.org/2014/10/mcad-general-information-p...
http://www.jacionline.org/article/S0091-6749(14)02927-3/full...
Dr. Anne Maitland’s presentation on Allergies & Mast Cell Activation Syndrome in EDS Patients. https://www.youtube.com/watch?v=ktFdr-9rpIM&feature=youtu.be