Weird skin phenomenon?

i used to have a scar on my knee shaped like russia. it disappeared. recently, i developed a rash in the exact shape of my old scar. it is in the exact same shape in the same area. its very bizaree. i was wondering why this is so and if i should be concerned about it. thanks.|||You should be concerned about it and see the doctor. Mght be something really minor but then you will be relaxed once you know the reason.