It might be worth a trip to the dermatologist. I've only been to family doctors. I haven't done much about it because it hasn't changed.
I went gluten-free (and dairy, soy, corn, rice and legume free) a year ago and it didn't change anything.
I've never heard of it, but just looked up. Maybe that can explain things. I've been to three doctors for what looked like ringworm to me. They all said it wasn't and that that it was probably an allergic reaction and would go away eventually. I've had it now for two years. It's not itchy, not getting in bigger, but definitely not going away and ugly...