i would be wondering as well but you cannot make an important diagnostic call based solely on a brief description. any skin lesion that is painful or changing deserves to have a professional look at it first-hand. if the dermatologist is not sure (not all skin lesions can be identified by appearance alone) then it may be recommended to have it surgically removed. you would then have a "cure" (since it would be gone) and a pathological diagnosis -- the most accurate.
painful mole or skin tag burns constantly. a few years ago i noticed a small bump under my left armpit. at first it never bothered me and i thought it was going to turn into a skin tag but it never has. it is like a small plateau shaped mole that is about the same color as my skin. it constantly has a throbbing burning sensation to it and sometimes stings like being stung or poked with a needle. it is more irritating than anything and i was just wondering what it could be?