My son is 7yrs old and he gets these itchy bumps only on his arms and just a couple on his legs, when he scratches them they get a little scab then go away. They come for a couple weeks then go away for months then return. What is this?

Because of the time of year it could be poison ivey or even poison sumac. Try putting some gold bond itching cream on it and it could help get rid of them

My son is 7yrs old and he gets these itchy bumps only on his arms and just a couple on his legs, when he scratches them they get a little scab then go away. They come for a couple weeks then go away for months then return. What is this?

Have you taken him to the doctor about this? Is it warm when this happens? It could be nothing more than a heat rash, but only a doctor can diagnose it properly.