Hello Sir, I have notices a small red spot in my hard pallate for about 3 weeks before, after that it lasts for approx. 07 days and go away, but surrounding area gets red spot as concentric circle, in this way is goes outside by disapearing the old one by forming new spot. I am an ex smoker, this type of symptom I have faces about 01 year and 03 year ago. please suggest sir.