Thanks for the query.
You might be suffering from urticaria
It is a chronic itchy condition and can be caused by anything,
A simple cloth, vegetable or plant can cause this.
You need to find out the cause and eliminate it.
Take anti histamine
tablets on a daily basis for at least a month.
Please meet a dermatologist
and discuss regarding this.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.