Hello, Welcome to healthcare magic. From your history and description, you seem to be having a condition called as dermographism. This is associated with raised wheals along lines of scratching or handling, which usually appear as lines. There is no definite cause for this in many cases and it could occur as a transient reaction in about 10% of individuals. Other causes identified are new food ingestion, new medications, worm infestations, infections like a dental caries or sinusitis. You could leave it alone if it is not bothering you. It will clear spontaneously in a few months time. You could also take an antihistamine like Levocetrizine orally at bedtime for 2 weeks if it is causing significant distress. Hope this helps you. Take care.