I don't think it's anything to worry about if some ME/CFS patients have a sharp tongue. First of all, a sharp tongue may serve us very well. It gets us noticed. Actually, I think it is our secret weapon. The last thing you would want in a disease like ME/CFS, which is largely ignored by the medical profession and medical research, is meek and mild patients just sitting there saying nothing. When you are being ignored, politeness is not the right tactic. Vitriol works better.
A sharp tongue, in combination with the medium of the Internet, I think has provided us with a way to fight against being neglected and medically overlooked.
Although a sharp tongue is not the only mode of expression that helps our cause. Sometimes patiently explaining the scientific details, or accurately depicting, via first hand accounts, the horrible symptoms of ME/CFS is also effective.
I certainly think I have developed a sharper tongue since getting ME/CFS. Although I think I am getting better at using it more judiciously. I think my sharp tongue arises mainly out of my irritability symptoms. Irritability is a one of the CCC listed symptoms of ME/CFS.
In my case, before I taking medication for it, my irritability was so severe, that my tongue would become razor sharp on some days, shooting critical words in all directions, and firing off caustic comments at the slightest provocation! Ask the people I live with! However, since I started taking very low dose amisulpride a few years ago (see
this thread and
this thread), which is an atypical antipsychotic, it really helped calm down my irritability and propensity to be annoyed at anything that moved. If I stop taking it, wow, I soon turn back into a vitriolic monster!
Irritability is a major problem in autism, and atypical antipsychotics are used in autism to treat irritability, so that probably explains why they worked well for my ME/CFS irritability.