Hello, and yes, I have a similar rash on my bilat legs from the knees to my ankles usually. The rash starts spontaneously and no OTC topicals work. I recently went to a Dermatologist who became very interested because he thinks I have Henoch-Schonlein Purpura (HSP) which is caused by inflammation in the blood vessels of the skin. Do a Google search and look at the pictures and then discuss your findings with your Dermatologist.
Good luck to you.