Mast Cell Activation Syndrome (MCAS) - discussion thread

I do not see patients with ME/CFS myself but I have talked many times with people who have seen hundreds of patients in a severe relapse - Caroline Kingdon, Nigel Speight, Willy Weir, Amok Bansal, Binita Kane, and others. I know that inflammation of the skin is not a general feature of PEM because they tell me that if they find a change in a appearance of the skin it is usually an indication of reduced blood flow - cold hands, blue or purplish colour.

Inflammation is defined in terms of a change in tissue due to blood vessel dilatation and permeability. Inflamed means 'like a flame' - red and warm. We are all familiar with it. There is no reasonable possibility that the people I mention have all missed inflamed skin.

Clearly there may be occasional people with ME/CFS who also have rashes. But this is not a general feature of PEM. And there is nothing in any of the diagnostic criteria as far as I know - which bring together the experience of hundreds of physicians - that mentions skin inflammation as associated with PEM.

 

I personally have had both rashes and what I assume is inflammation appear ever since PEM started causing allergy like symptoms. The “inflammation” is redish warm skin, that is painful to the touch, but the pain is “deep” while a rash the pain is on the skin directly, when it happens to my toes, I can see that toe is visibly larger than the other ones.

My GP says the cause is MCAS, I’m not sure what to think about that label. But it definitely feels like those symptoms, which I call “allergy like symptoms”, are related to my ME in some weird way.

Definitely does not seem to be a universal feature in ME though. As Jonathan says.

 

That is an interesting observation but in what sense can we say PEM causes something? PEM is just some worsened, or wider spectrum of, symptoms. So are you saying more than that you have been having allergy-type symptoms ever since you had allergy-type symptoms? This is the problem with disentangling histories of illness. I get rashes and red toes too - since I got rashes and red toes. But they aren't anything to do with ME/CFS or even my two episodes of Long Covid. Knowing what causes what is tricky.

And as you say, these things do to seem to be specific or general to ME/CFS with or without PEM.

I don't think a diagnosis of MCAS means much unless you have abnormal test for tryptase or something like that. Without such tests there is no way of knowing that it is the mast cells that are over-reacting rather than reacting to something they are supposed to react to.

 

By PEM causing them, I mean they wax and wane similarly to my other ME symptoms in response to exertion.

 

Is it like ordinary allergy symptoms? For instance, when you're allergic to a drug and large expanses of skin are covered in a raised, scarlet rash that feels really hot to touch? That's like having burns—the only time the pain stops is when you put a cold pack against the skin. I'm wondering if there's a bigger range of skin symptoms, though.

 

The rashes yes. It’s sudden itchines and pain presenting as hives which I get in reponse to overexertion.

 

I agree, any of the MCAS symptoms, other than Anaphylaxis, could arise in ME/CFS for other reasons. Do we have any specific evidence of people with ME, or at least a subgroup, responding to treatment for mast cell activation and/or having signs of mast cell activation on testing?

[added - looking at the medications used for MCAS, potential side effects of antihistamines overlap with ME symptoms, and corticosteroids are generally not something you would want to take unnecessarily.]

 

I'm absolutely not doubting anyone's symptoms, and I understand why people have become attached to the diagnosis, but most people with a serious scientific, or academic medical, background who read Afrin's book "Never Bet Against Occam" - which essentially introduced the concept* of MCAS - will recognise how deeply flawed his ideas are very quickly indeed. I don't think we've discussed it on S4ME before?

(* Well, it didn't quite introduce the concept; prior to Afrin there were reports coming out of Germany of a "monoclonal mast cell activation syndrome" involving a few patients who had been investigated for mastocytosis but where bone marrow infiltrates were not sufficiently dense for that diagnosis. Afrin reconceptualised & popularised it and began applying it to broad swathes of very heterogeneous patients. I skimmed through his book years ago and the flaws in his ideas were very obvious & evident from the early chapters. Some of it was really quite strange.)

 

A friend who had ME/CFS for over 37 years had what he called mastocytosis. I think Dr.Paul Cheney investigated it since he was his patient.

 

Yes that’s what I was diagnosed with. I thought it was just the french name for MCAS.

 

So it’s a poorly though out name (and mechanistic assumption) for a constellation of symptoms. Just like “POTS”, “EDSh”, and arguably “ME” is.

 

I don't think it is that much of a puzzle. Clinics taking people with ME/CFS have often been run by allergists. Stephen Holgate was I think primarily a chest physician with an interest in asthma but also did other allergy. Jonathan Brostoff saw a lot of people with ME/CFS and was primarily an allergist. Other allergists got involved, especially in the private sector at places like the Brakespeare Hospital.

My memory of news items from forty years ago about people confined to bed, unable to leave a single room, nearly always focused on 'multiple allergies'. That seems less so now, maybe because allergy tests never turned much up. The people may have had ME/CFS for all I know.

Rather like the EDS situation, allergy and 'fatigue' seem to have been lumped together, maybe as a way to explain the 'fatigue'. MCAS would have been a useful diagnosis for the private allergist who could not find any allergy because MCAS is supposed to be just that - mast cell activation but not allergy. If it was allergy it would just be called allergy. It has become a stock in trade diagnosis for private allergists.

The catch is that the sorts of rashes we call allergic probably look the way they do in good part because they are allergies -with antigen being localised by specific mechanisms leading to specific patterns like drug rashes. It remains very unclear exactly what symptoms are supposed to be typical of MCAS. As others have said it often seems that anything will count.

I doubt that many have had any of these tests. I am also pretty sure that the tests are not considered diagnostic of anything. To claim that there is a hypersensitivity of mast cells you really need something like a genetic mutation in tryptase or some such. Raised levels in urine might be due to real allergy - and that would not be MCAS.

 

I think by definition, mastocytosis cannot be MCAS. I was under the impression it's supposed entail everything that cannot be mastocytosis but somehow has resembling symptoms.

 

What triggers mastocytosis?
There are dozens of potential mastocytosis triggers and not everyone with mastocytosis reacts the same way. Some activities or experiences that trigger the condition are:

• Having something touch or rub on your skin so it causes friction.
• Participating in exercise and physical activity.
• Being bit or stung by an insect, especially ants, wasps and bees.
• Drinking beverages containing alcohol.
• Eating certain foods, particularly spicy foods.
• Taking certain medications, including nonsteroidal anti-inflammatory drugs
• Experiencing sudden changes in temperature, like jumping into very cold water.
• Having physical or emotional stress

 

Mastocytosis is something quite different, where there is evidence of an abnormal clonal expansion of mast cells - almost like a leukaemia. It is a well documented pathology.

 

Where does that come from? It looks like disinformation - talking about spicy foods and stress.
And talking of 'what triggers mastocytosis' suggest that whoever wrote it doesn't have a clue about medical matters.

Edit: just looking up on Google, the internet is, unsurprisingly, awash with disinformation about mast cells.

 

I also think there is a group of people that get red/blue feet and hands from being upright too long and/or too hot. My guess is that it happens more frequently in people who are given the POTS label and is probably worse when general symptoms are worse. To me it feels like the opposite problem of reduced blood flow as it is hot and itchy. I still wouldn't describe it as inflammation though as it usually only persists while standing.

 

Yes, that sounds like some sort of sympathetic flushing mechanism rather than inflammation, if it is both hands or both feet - neurally mediated.