My son is 11 and has had a red body rash on his back, stomach, chest , arms, legs and neck for 1 week. It is progressively getting worse. Two weeks ago he complained of his back and neck hurting but said that has stopped. When he was outside today at school, the rash turned bright red and is extremely worse than before. He has started with a stuffy nose last night. I am not sure if I should get this checked or if this is something viral that could go away?