Help my son with unknown illness

This is my son Landon. He just turned 1 on September 3rd 2017. He spent his first birthday party in the ER. He has had this unknown rash since he was a month old. We've been to 3 hospitals and multiple doctors including a dermatologist, 2 allergist, and multiple ER doctors. Not one can give us answers on what it is. The dermatologist said he'd out grow it. The allergist said he's been doing it for 30 years and hasn't seen anything like it. No one will test him because of his age. We had an appointment at Rileys Children's Hospital in Indianapolis in November but decided to take him to the Rileys ER. They did a blood test and tested for 11 different things and a few tests came back high but still no answers. Now they're telling us wait until our appointment in November. He has been dealing with this for about a year and no doctor has helped us. They all say it's not life threatening but without real tests being done, there is no way of knowing and what it's doing to him internally. Each one gives him steroids and it goes away, but as soon as we stop the steroids, it comes back with a vengeance. Tried getting him into the Mayo Clinic, but they said they don't accept his insurance and want $5000 upfront for an initial consultation and basic testing and doesn't include any further testing. Money is getting tight with medical expenses not covered by insurance and multiple things that Landon might need plus gas and upkeep to my vehicle with multiple trips to the hospital and Indianapolis and anything would help. When a doctor says it could be anything from Lupus to Cancer, as a parent, it scares the hell out of you. I hate making a gofundme page but I have to put my pride aside and do what I have to for my son. God Bless everyone. If you can't donate, I completely understand. A simple prayer would be much appreciate. Please help my little Raider.

P.S. For everyone who has asked, this is not ringworm.