My profile pic has the rash I'm talking about. They started as a solid red area then expand to a red ring with a clear spot in the middle.
Looks like "port wine stains " to me.
Which is a type of birthmark.
My dad has those, and he finds they are more noticeable during certain times of the year as well...because of weather conditions I guess.
You would need to see a dermatologist in order to be positive.
Not sure where you live, but could it be some sort of bug bite?