MCAD Resources

Edited in December 2022 to add: We have just become aware that there is an international shift in the nosology (classification and description) of the many forms of mast cell diseases, since not all involve (over) activation. So, the term Mast Cell Diseases or MCD is now the over-arching umbrella term to include all we know about now, plus any future discoveries. (It used to be MCAD.)

Not all with forms of Mastocytosis have mast cell activation and vice-versa.  And the recently uncovered Hereditary Alpha Tryptasemia Syndrome (aka HaTS, alternatively Familial Tryptasemia) confirmed in 2016 is sort of its own category at this time.

I am slowly reworking and rewriting all of my pages to slowly reflect this, but I have a lot of material to work through with no help while I’m disabled. So I thank you for your patience as I catch up. End edit.

Here’s a general collection of useful and informative websites to drill down further on all forms of Mast Cell Diseases (including all forms of Mastocytosis and MCAS and now also HaTS) known collectively as MCD and food issues that so many of us experience in addition to the Ehlers-Danlos Syndromes. Scroll down further for some of the best introductory articles for doctors regarding diagnostics and treatment.

Unfortunately, the more newly recognized MCAS (since about 2010) is a very complex condition that is hard to describe, and especially hard to diagnose unfortunately. There are no easy simple tests, and patience and perseverance is in order for everyone – doctors and patients alike, sorry. I highly recommend joining The Mast Cell Diseases Society for support with same. (Free to join.)  Last Updated March 15, 2024.

Emergency Protocols for Mast Cell patients via TMS <–Link (there are more below this section)

There’s now an educational book available on MCAD from a leading US hematologist as of May 2016:

Never Bet Against Occam: Mast Cell Activation Disease and The Modern Epidemic of Chronic Illness and Medical Complexity Afrin, L. MD 2016 Elsevier Press

Good introductory info for all

I highly recommend reading these blog posts on diagnosing all forms of MCAD, which make it clear both how hard it is to get a distinct result, and how heterogeneous (widely varying) and hard to diagnose the conditions are for everybody:

Important note January 2021 regarding COVID-19 vaccines: it is recommended to try to get your vaccinations. That said, MCAD patients with known high levels of reactivity to medications or past vaccinations may wish to pre-medicate with Benadryl or other antihistamines in concert with your doctors knowledge and advice. Some may even need to receive the vaccine in the hospital or doctor’s office for safe observation. Talk to your doctors about your individual case. (I succeeded with pre-medication myself in 2021 and 2022. Consult TMS for further guidance if your doctor can’t help.)

Is it a zebra or what?

Anaphylaxis presentation and grading charts

Not all anphylaxis (ana) is throat-closing. Learn the early warning signs to help stave off a reaction that is.

These are just some sample charts below, google for more, there’s no single consensus, and everyone’s body reacts differently at different times to different triggers and conditions including to non-proteins like sunlight, pressure, and vibration. Some poorly known experience from the field:

Some people’s blood pressure (BP) may just suddenly drop hard and they begin having literal Stage IV cardiac issues that can kill them even without “traditional” hives and airway trouble at first, if at all. So they can be missed as having anaphylaxis because of the absence of throat or tongue swelling or any skin signs (hives, flushing).

Others have their BP spike quite high, and either stay high, or also suddenly drop, sometimes quite far and hard, again, in a dangerous way. Talk to your doctors about yours and when to epi! Every. Body. Is. Literally. Different.

Terminology note:

Anaphylactoid reaction” is an outdated term referring to reactions which are essentially identical in effect to the newer term “nonimmunologic anaphylaxis” and can present identically to an allergic reaction. The difference in terminology is merely a matter of hair-splitting around the drivers of the reactions.

Allergic reaction” is a very narrow definition of a reaction based strictly on IgE-mediated “true” allergies, triggered by organic protein “allergens” they can easily test for. These can only be triggered by organic proteins, not chemicals.

The former (“anaphylactoid reaction”) is a now outdated term that was used to described all other reactions of the same nature in the absence of a known IgE allergen. The newer preferred term for this is “anaphylactic reaction”.

Because they can affect you just the same! I.e, the “driver” (nature of the trigger) doesn’t matter, the resulting anaphylactic reaction is the same – over-activation of mast cells and basophils usually leading to shock and potentially even death for some.

Most people with any form of MCAD soon learn this is one of the MAIN REASONS TO SUSPECT MCAS or Mastocytosis or HaTS: the fact that you DO react to non-proteins, like sunlight, vibration, pressure, cold, heat, scents, etc.

I.e, Things you cannot test for IgE antibodies levels of at the allergy office~! Some never have any “true” IgE-mediated “allergies”, but have to literally live in safe trigger-free bubbles just the same.

This is precisely what makes diagnosing MCAS SO hard – the best they can do is try to capture evidence of elevated mast cell mediators in blood or urine “after the fact”, and this is notoriously inaccurate for many reasons.

People have been literally dying, and disbelieved because there was no easy bio-marker or sufficient elevation of one despite all the signs of anaphylaxis you could want. This really really needs to change and is always under discussion by TMS, AAAAI et al. Sadly, there is no global consensus yet. (2022)

Table showing the Ring and Messmer grading scale for anaphylactic reactions

Ring and Messmer Anaphylaxis Grading Scale from 1977

[Image description: a graphic of the 1977 Ring and Messmer Anaphylaxis Grading Scale showing a table with the headings listed as Grade, Skin, Abdomen, Respiratory Tract, Cardiovascular System across the top from left to right. Four rows labeled simply I, II, III and IV top to bottom are in the left most column, indicating Grades of anaphylaxis.

Skin signs by grade have Itch, Flushing, Urticaria and Angioedema listed under all four Grades 1-IV.

Abdomen lists the following for the respective grades I-IV:

  1.  — (nothing)
  2. Nausea, Cramps
  3. Vomiting, Defecation
  4. Vomiting, Defecation

Respiratory Tract lists the following for the respective grades I-IV:

  1. — (nothing)
  2. Rhinorrhea, Hoarseness, Dyspnea
  3. Laryngeal edema, Bronchospasm, Cyanosis
  4. Respiratory arrest

Cardiovascular System lists the following for the respective grades I-IV:

  1. — (nothing)
  2. Tachycardia (rise >or= 20/min), Hypotension (> or = 20 mmHg drop in SBP), Arrhythmia
  3. Shock
  4. Circulatory arrest                                              — end image description]

Google for more and for any unfamiliar terms and talk to your doctors! Loss of airway is the biggest flag for most, but not all.

New COVID-19 related articles:

Emergency Protocol

Emergency protocol form for Masto/MCAS patients to fill out and carry via The Mast Cell Diseases Society:

 Caution: Patients on beta blockers may need glucagon WITH any shot of Epi. (Disregard if NOT on beta blockers).

(See TMS Emergency Protocol document above for more, including cautions re: anesthetics/surgery)

Link to: Emergency Protocol for Those With Severe Corn Allergy    Patreon support logo

Best Introductory Articles for Doctors 

Video: Mast Cell Activation Disease: Current Concepts with Particular Notes on Hypermobility and Chronic Pain – Lawrence Afrin, MD 2018 via EDS Wellness/Mast Cell Research
Video: Mast Cell Activation Syndrome webinar with Dr. Larry Afrin, US Hematologist via Chronic Pain Partners June 22, 2016 (since he published Never Bet Against Occam, book)
Video: Introduction to MCAD (June 2015) – Jan Groh for PNW TMS Chapter
Video: Allergies and Mast Cell Activation in EDS Patients Anne Maitland, MD 2014
Video: Mast Cell Activation Syndrome in EDS Patients (Part 2) Anne Maitland, MD 2016
Video: Mast Cell Disorders – free webinar by Dr. Theoharides via Chronic Pain Partners June 2, 2015
Video: My Mystery Symptoms and Mast Cells – featuring Dr. Theoharides and two patients in discussion 2015

Find more up to date videos on both MCAD and EDS at

The Mastocytosis Society MCAD Symptomatology Video on Youtube (3 parts, 45 min total):

HATS – Hereditary Alpha-Tryptasemia Syndrome (new since 2016)

Video: Update from Josh Milner MD of the NIH on study of CTDs (like/including EDS)/MCAD/POTS aka “Familial Tryptasemia” – high tryptase level not required 2015 via Dysautonomia International. See articles below for study results published since October 2016:

Video: The Bulk of The Iceberg Revealed: Mast Cell Activation Syndrome Dr. L Afrin in South Africa Aug 2014 (slow to load and often buffers)
Podcast on Coffee Klatch: Dr Theoharides – Mast Cell Disorders – April 2015 – announcing connection between autism and MCDs

More on Mast Cells and Connective Tissue Issues:

GI Issues and MCAD

Mast Cell Mediators

Mental Health and Mast Cell Activation Diseases (Masto, HaTS and MCAS)

Migraines and Mast Cells

Enlightening Histamine Articles

The Interaction of Hormones and MCAD

Miscellaneous Links

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Or even just once here: 

Thank you so much!

Please notify me of any broken links, thanks! Jan ( Updated 2/11/22

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