I was suffering from cholinergic urticaria from past few months. I also had chronic pain in my wrist.
The doctor recommended blood test in which I got to know that my ESR level is very high. The doctor recommended medicines and injection for it. After taking those medicines for a few days, my itching reduced and after a month it is almost gone.
I also got to know about a patient whose ESR level was very much higher than mine. She also had problem of high ESR level. So I think that the main cause of cholinergic urticaria is high level of ESR.
So I recommend to everyone who is suffering from cholinergic urticaria to get ESR level checked.