Hi J,
I sometimes get sensitivity when inject in my abdomen. I use NovoRapid too. Sometimes the injection site itches for sometime after I've injected, even as long as 2 hours. I never get this sensitivity when I inject in other areas.
I also have other of the "immune" conditions, hay-fever, allergies, psoriasis, bronchiospasm (mild) and have found that when my abdomen reacts like this, it is also when the other conditions are worse. There may well be a link.
I also feel (excuse me if I missed other posts and am repeating things) that your son may be responding emotionally to the whole thing. That's not to say it isn't happening, but if he's afraid of diabetes (we've all been there!) then he will get angry with it and find a reason to hate it all the more...I can see that it might take some time for him to get used to the idea, but in the meantime if you can encourage him to use other injection sites.
Also tell him about me. I'm 46, live a really active life, travel a lot with work. I've had diabetes since I was 10 months old and up until now I am one of the lucky ones with my only complication being a TINY amount of retinopathy (the kind that the opticians say is common amongst people of my age WITHOUT diabetes)....you don't have to tell him about the retinopathy, but basically that it won't necessarily stop him leading a happy and healthy life.
I started injecting myself when I was 10. I'd already been diabetic for over 9 years but it took my parents quite a bit of persuading to get me to do it myself. I had grown up having injections since the age of 10 months and had got used to having my parents do the injections and urine testing with me. Curiously, when my father did my injections they almost always hurt and continued to itch for sometime afterwards, and when my mother did them, they were painless and simple.
This was clearly due to my father's anxiety about diabetes and my mother being more relaxed. They used to share the injection and testing time and we always did it away from my two elder brothers.
When I started injecting I found it really difficult to inject into my abdomen. It made me squeamish about the whole thing and I much preferred my thighs, buttocks or upper arms.