I agree, you're doing a phenominal job at researching and pushing doctors hard for answers, or at least a direction to take. I also don't have children, or much experience with them. However, what raised the red flag for me while reading your posting, was that your son has extremely bad eczema, and a slightly red rash on both cheeks that is not eczema. Eczema is a classic sign that something autoimmune is going on. Psorisis is another skin condition related to autoimmunity. The raised reddness on his cheeks "could" be the lupus butterfly rash.
I agree that seeing a rheumatologist is crucial at this point. Don't be surprised if you end up seeing many specialists along this road to a diagnosis. I think I went through 5 or 6! It's normal. Don't get discouraged. In the end, you'll have a plethora of information that will all help in getting a diagnosis of something, whether it's lupus or not. All information is helpful.
Also, make sure you take pictures of your son's rashes. Very important. If you can, take them in natural lighting with no camera flash. You'll get a much more precise record of what the rash looks like, its color, texture etc. (I'm a photographer )
Keep a daily diary of all his symptoms, how much he eats, sleeps, and mentions how often he hurts, and where the hurt is coming from. Document as much as you can.
As a child, I had continuous problems with strep throat. It was constant. I had my tonsils removed at the age of 8 and I seemed to get better once those were gone. But looking back, that might have been one of the triggers to my lupus. I remember having extreme eczema at the age of 13-18. And I had a lot of pain in my knees during those years too. Along with jaw joint issues that required surgery. Your son's symptoms are not to be ignored at all by any doctors. They're not growing pains. Not when he has all these other issues happening. If you don't like a doctor, lose them! Going back to your old pediatritian is a good idea. I'm glad you have someone who truly listens.
Please keep us posted on how everything is going. Don't be afraid to ask ANY questions you have, okay!
I can do anything through Jesus Christ who strengthens me. I have learned in whatever state I am in,to be content. Phillipians 4:11-13
33 years old. Diagnosed with lupus in 2000. Fibromyalgia, anti-phospholipid syndrome(APS)(stroke),Sjogren's, Raynaud's, seizure disorder-(miraclulously disappeared!), Libman Sach's Endocarditis, vasculitis, sacroiliitis, neutropenia, thrombocytopenia. Prednisone, Imuran, Coumadin, Clobazam, Amitriptyline, didrocal, monopril, calcium, Cykolokapron, multi-vitamin, vitamin D, Magnesium, vitamin B6, Acidophilus