I itch a lot when I am praying in the mosque when other people are present behind me. However, when I pray alone, I don't itch at all. What may be the reason behind the itching?
Do you think you might have an allergy to some things on other people (such as cologne, pet dust, laundry detergents, foods, etc) which become magnified when you are in a crowd close together, or some things at the mosque (carpet, dust, mold/mildew, etc)?
And could there be a psychological reason too, such as social anxiety?
Anyway I hope you are able to find a cure for your itching, inshallah.