Im getting a red rash on body every now and then it itchy and not bothering much. its been more than a week. line like itchy rash. it disappears after sometime and itchy ness starts elsewhere. should i worry about anything?

If you rub your skin and an itchy raised red line appears you may be dealing with dermatographism which is a relative of hives. The cause is very elusive & some consider it an autoimmune disorder. If the symptom persists, I recommend consulting a dermatologist or allergist for evaluation and advice. In the meantime you could try taking an antihistamine.