Hello Dear doctor , I recently noticed my 16 year old son s right arm , inner side covered with these circular marks ,slightly dented, looks like cigrette burn , definately not, a few on the chest skin. He is on a trip away from home. I just realized that I should have taken it seriously but I have to take him to the doctor in a week s time when he is back. The more I think about it, the more I am worried now. He is a sporty and healthy boy . He plays violin. Could it be that he played too much recently? Do you by any chance know what he has got this circular dents on the skin with slightest difference in colour, feeling nothing discomfort what so ever. Thanks a million