I am assuming your mean vulva itching and peeling. Your vagina is INSIDE your body
I am guessing it is a contact allergy. I suggest: 1) Wearing cotton underwear. Throw out your lace undies, those are like sand paper for the vulva. 2) Don't wash down there with soap or use lotion down there - warm water is enough. 3) During your period, try to use an organic cotton pad or tampons to avoid allergy or irritation.
Could you be alergic to anything? Maybe a type of new product you're using so that causes the peeling and pain?