For a month I have had red itchy almost pimple like rashes that started behind my ears on shins and are spreading on elbows etc. it's almost like they appear out of nowhere, start itching and within a few minutes a red bump like rash forms. Have been putting topical cortisone cream which alleviates the itch a little however it dries it out and the rash turns light brownish but still stays there for a while. Help!