We are dealing with something similar, they just keep throwing a new antibiotic at it. My son is older -14- but we are on the third month of this. About to go to Progressive Medical. I had problems 6 years ago - no regular doctor could figure out. I had some thyroid issues and kept breaking out in hives - turned out compromised immune system snd then body starting reacting to everything. Mostly foods / allergic to gluten, chicken, dairy, eggs. If you are in Georgia, Atlanta area, I would suggest Progressive Medical or other similar doctors group - they get to cause not just treating symptoms.
Is there a specialist you can be referred to? I know how it feels not to know why thing happen to youy young child and it is very frustrating! Keep us posted, I have never heard of that. He does look like he feels miserable. Poor baby! My prayers are with you and him.