About 6 weeks ago I developed a weird very itchy oval-shaped rash in the crook of my left arm that got progressively worse over several weeks. I ve had Lyme, poison ivy and brown tail moth rashes before and this didn t behave like any of these. I was worried it might be ring worm so I went to an urgent care clinic. The doctor on call said it did not look like ring worm, but didn t know what it was. After a few days on prednisone, the rash finally went away, but it left behind a still discernible scar. There were also a few little itchy patches outside of the oval that have left brown spots on my skin. About 3 weeks ago I developed a sore shoulder and upper arm on the same left arm. Feels like muscle soreness, but hasn t diminished in any way. Are the two symptoms related? What could it (they) be?