I can not give you exact reason of Redness, Itching, Rash, Burning, And Swelling of the mouth without looking at you but it seems to me that it might be a drug reaction. Some drugs like benzoyl peroxide and benzocaine dental gel. It can also be due to some allergen from the swimming pool. It will be good to see a doctor for proper diagnosis and treatment.
I Have Redness, Itching, Rash, Burning, And Swelling On And Around My Mouth... What Do You Think It Is?
Dear! It might be because of acidity or ulcers in your stomach go to the doctor and check yourself as he will prescribe best medicine to you.