This is due to dermatographism. Dermatographism can be caused by stress
, tight or abrasive clothing, watches, glasses, energetic kissing, heat, cold, or anything that causes stress to the skin. In many cases it is merely a minor annoyance, but in some rare cases symptoms are severe enough to impact a patient's life.
It can be treated by antihistamines or cromoglicate and sometimes steroids, as they prevent the histamine from causing the reaction.