From my own experiences I have definitely got more sensitive to pollen and animal allergic reactions (stronger and more frequent) since getting ME. I also had IBS develop after onset which I would conclude was a downstream affect in my case. This is now controlled and I only get it when I crash (so not really ibs I suppose ..just the same symptoms over 1-3 days). I know when I’m coming out of a crash since things get back to normal. Despite the ibs being under control, my sensitivity to contact with animals is still pretty severe.....my neck swells/get hives from wearing the cashmere scarf I used to wear fine before I got ME for example.
I take an antihistamine daily and this seems to help take the edge off of symptoms and is sort of mildly helpful (although I would need to do it for a few more years to be sure).
I wonder whether there is something that creates a variable high homocysteine (not necessarily simple deficiencies ...could be knock on effect downstream of something else, or liver?) when we crash and this is what causes high histamine or histamine to wax and wane as environmental and food from normal levels for the healthy become temporarily difficult to handle. If so, the more severe you are, the more likely that this is to be a continuous problem. As I mentioned I don’t think in my case this is a fundamental aspect of my ME, more symptoms as a knock on effect of something else.
I’ve never had an anaphylactic reaction to food and I am yet to see anyone on forums describe anaphylaxis directory relating to their ME. However there are enough PWME reporting digestive and allergic symptoms to suggest that something is going on more than the usual confusion in the general public overstating normal reactions and food preferences to intolerances etc.
Of course this is highly speculative on my part ...so I’m just postulating with very little energy to hunt for papers or references.
I wonder whether there should be a larger study on homocysteine levels in the blood for ME patients and monitor it over a period of time to see whether there are unusual fluctuations? I think there was a small study done that showed there may be high levels in ME patients, but I don’t think anyone tried to take this further or replicate it with something more substantial. This is from memory so just bear in mind it’s not great at the moment. It’s possible this has been thoroughly debunked or dismissed when methylation was on the way out as a theory.
Anyway I promised I wouldn’t post and I’ve already broken my rule...back to lurking.
Edit: I haven’t properly read this but thought I would post here since I think it’s interesting the link with homocysteine and other neurological conditions...don’t know whether it’s any good yet.
https://jamanetwork.com/journals/jamaneurology/fullarticle/777652