Hello Terry,

I am sorry your little man is struggling He might be having referred pain. The rib cage had many nerves travelling through the cartlidge between them and pain can be referred along them making you feel as though you have back pain, chest pain and also pain down the arms.

Perhaps he has somehow irritated them, maybe just from falling asleep in a funny position or stretching and this is the result
Does he have a temperature or a cough? Pleurisy can sometimes give this type of pain too but I am sure you would have seen other symptoms.

Maybe a hotpack and even just a small dose of plain old paracetomol or aspirin might help but I do agree with the doctor to try and keep him moving as much as he can tolerate.

Let's hope this is something that will just ease off over a few days and prove to be nothing to do with his RSD.
I am thinking of you both
Tayla