A race car for a child with a rare skin disease doesn’t sound like such a wise idea. But that’s just the kind of little boy Payton Thornton is: tough.

Sure, the slightest bump could lead to blisters and scarring, but the threat of pain has never slowed down this White Plains boy. Payton, now 9 years old, was born with recessive dystrophic epidermolysis bullosa — “EB” for short. Children born with EB lack a protein that anchors the layers of skin together, leaving them prone to blisters, scabs and scars.

“He knows his limits, and he’s learned to be cautious,” said Joy Thornton, Payton’s mother. “It might not sound like it, but Payton knows what he can and can’t do. And he can ride that thing wide open.”

The race car was originally a Christmas present for Payton’s 11-year-old brother, Parker, who soon grew tired of driving his little brother around. After a little cajoling, Payton climbed into the driver’s seat. EB has caused his fingers to fuse together, or “mitten,” so Payton’s father, Reid, built him a special steering wheel. Now Payton is the one driving his little brother, 4-year-old Paxton, around the yard.

“They’re like two peas in a pod,” Joy said of Payton and Paxton. “And it makes sense, given what they’ve been through together.”

 It’s been four years since Payton returned from the University of Minnesota after receiving a bone marrow/stem cell transplant from his baby brother. During the first year or so after the experimental transplant, Payton’s body was producing the missing protein, but as he enters third grade, his progress has leveled off.

“It’s not getting any worse, but it’s not getting any better,” Joy said. “I’m a little disappointed, and Payton’s frustrated. He’s 9 years old now and understands more what’s going on. He’d like to be further along, but there’s only so much we can do.”

The family stays in contact with the doctors in Minnesota who pioneered the transplant in 2010, and who are currently working on a new procedure. Using the same cells they harvested from Paxton, doctors want to inject mesenchymal stem cells (MSC) directly into an area in hopes of stimulating the growth of new skin cells.

The procedure is in the trial phase, but Joy hopes to be back in Minnesota sometime next year. “Patience is something you have to have with EB,” she said.

Payton is “way” better off than he was four years ago. Back then, layers of bandages covered Payton from his chest to his toes, and the routine of bathing and dressing changes took upwards of six hours. Now, “if I really, really hurry, I can get it done in 45 minutes,” said Joy.

Payton’s main trouble spots are on his upper arms, hips and a few places on his legs.

“We knew all along it wasn’t going to be a cure,” Joy said. “Sure, we hoped, but we knew it wouldn’t be. Still, he’s come so far. We got him some relief, and that made it all worth it.”

Just before the kids started school, the whole family went to the beach for a few days. Payton couldn’t go out during the heat of the day, so he’d sit on the hotel balcony with his grandmother and watch the people down below, or ride go-carts with Reid. Then at night, he’d go out on the beach and look for crabs scurrying across the sand.

“He’s just a typical little boy,” Joy said. “He’s happy as can be.”

Contact Brett Buckner at brettbuckner@ymail.com.