Hi C.,
My little cousin had the exact same thing happen to her. Her mom placed a coffee cup on the edge of the counter. She came by and emptied all that coffee on her face and neck/shoulder. The only difference was that she didn't take him to the emergency room (that's a different issue!)
My brother also had been burned several years ago. He had 2nd and 3rd degree burns on his chest, arms and legs.
I did some research and EMU Oil helps burns A LOT. I ordered a bottle for each. You just try to massage it on the affected area ( as much as you can). They both now don't have any scars left. My mom (who was taking care of my brother) said that it really helped him with some of the itching.
Look up EMU oil on the internet. You'll find many testimonials. Hope this helps your little one.