A.G.
I had the testing done myself, and it was only a minor discomfort. It felt sort of like someone was scratching me. It does not feel like needles are poking you. But for a 4 year old it will be very difficult for him/her to keep still... anything you can do in that department will be helpful! However the process is very quick- they do the scratching test, then you have to wait something like 20 minutes, then they come and "read" the test.