I have a small dark pink nickel sized rash on my inner thigh. Literally appeared in one day about a week ago. it's uniform in color and nearly perfectly round. light layer of pus like after a broken blister is always there. It does not itch or hurt at all and in no way is painful or irritating. not ringworm as the color is perfectly uniform. but the fact it is not fading and is nearly a perfect circle is weird. I have not been sick or taken any medications of any kind. it's not bumpy, just a uniform perfect little dark pink circle that is not getting any bigger or smaller. Help!