Now that I've seen the pictures... Pityriasis rosea. Medically: cause unknown, although sometimes follows a respiratory infection. Usually goes away on it's own in 4-8 weeks. If you read the links, the time line of events sounds like what you were describing. The raised edge around the spot was the clue. 6% of cases are on extremities. It's usually on torso, and develops from a single spot, into a "Christmas tree pattern". That threw me until I found that 6% of cases were on extremities instead. Sunlight helps heal faster. Try to get some sunlight on the areas. Even an ultra violet lamp will work. Don't get a sunburn from the lamp. Avoid scratching and harsh soaps. The anti-histamine is for the itching. The change in the muscle is weird, and that was near the initial start area? WebMD Mayo ClinicMedicine Plus gov disclaimer: I am not a Doctor. I didn't even stay at Holiday Inn Express.