question: Hi doctor, Could you, please, tell me what is the reason that inside my cheeks, especially the left side feeling like dry sand paper? I don t smoke , no STDs , don t drink. It seems like it is spreading slowly, but there is no pain, no swolling, no blisters or white patches . Just seems like the wetness of the tissue is gone. Please, help understand what can it be. thank you for possible help...