I'm so sorry to hear about your son but am glad that he is doing better. What a scare!

As for the knee...I think it has flared up the RSD. The other day I was putting something in my purse and my hand (where I have RSD) brushed the velcro and oh my god did it BURN! My whole hand got red and swelled up and felt like it was on fire. This wasn't even a bad scrape...no blood (though there were a couple of small scabs I noticed the next day once the swellind went down so it obviously broke the skin)...but holy crap I felt like my hand was sitting in a ball of flames for days afterwards. So I think the extra burning pain is most likely stemming from the RSD as opposed to just the scrape itself.

If it is not healing up yet then I think you should make an appointment with the doctor. It could be infected despite everything they did to clean it out...which could just be making things worse. You may need stronger antibiotics or different ones. If it was deep then it may take a little longer than normal to heal but it should at least show SOME signs of getting better by now.

I have heard that RSD can weaken the immune system and make it more likely for us to get infections...so maybe that is also part of the problem? But I would definitely make an appointment with a doctor to get it checked out. If it happened at work (did you file an accident report?) make sure you know the laws and if there are any special doctors you need to see or if you can see your own, etc. They should pay for all your medical care but you have to follow their procedures in terms of what docs you can see. These laws vary by state so I'm not sure what they are in your area.