I noticed that every morning my mouth skin as well as the inside of my mouth skin is peeling. is toothpaste allergy the possible cause to this ?

Sensitivity: It is more likely a sensitivity to an ingredient(s) vs. an allergic reaction. Have you changed toothpastes or mouth rinses in the last 3 months? Often less is more when trying to figure this out. Try switching to a basic, no frills toothpaste/mouth rinse. Often this type of reaction is due to a chemical sensitivity to a flavoring, whitening, or tartar control agent. If no change see your dentist.