Hello, a few months ago I had a random mark on my arm. It was a very hard scab lookinh bump with a huge red mark around it, probably as big as the width of my arm. It was itchy, and my arm had sharp pains. Maybe a week later it went away. Now 2 days ago it reappeared in the same exact spot, same symptons. I would go see my doctor but I dont have one, is it something I should go to the er for ?