If your rash gets worse in the sunlight and is "coin" shaped it's possible that you may have a rash that is caused by Cutaneous Lupus. This is NOT Systemic Lupus that affects internal organs. Cutaneous Lupus (sometimes called Discoid Lupus because of the coin-shaped rash) affects the skin. Cutaneous Lupus is difficult to diagnose merely by a check-up it is usually diagnosed from a skin biopsy. Also, there are 2 different "rashes"(one scars the skin, do you have scars?) and the other does not leave scars but there are also other symptoms like joint and muscle pain, fever and "general" discomfort. If the rash develpoes on a "hairy" region it may leave a bald spot. This condition mainly affects women and the causes are unknown. Treatments range from corticosteriod creams to prescription medication depending upon the severity- and of course keeping out of the sun. If you check out a Lupus website remember that Cutaneous Lupus and Systemic Lupus are as different as Dandruff and Luekemia.