hi, you are suffering from symptomatic dermatographism. I suggest you take tab allegra
180 mg once daily. take tab daily for a month and then see if your dermatographism has subsided or not. if not then continue treatment for another month and so. dermatographism is a self resolving problem and 70-80% patients get disease free after a 5 year period. medications are for controlling the symptoms and are safe for long term use.