I had this itch one day, and it was all over my body, and at some point I just start grunting and screaming, and I have to get water on my body to close the pores. It's not a normal allergic reaction that is deadly, it is just intensely painful. HOWEVER, I figured out how to STOP this ITCH finally. I could not find an answer, really online. I had to experiment myself. This is how I deal with my itching. I realized that Cheese, Soybeans, spinach, and anything high in histamines cause this itch, because my body cannot absorb them fast enough. So when I stop eating these foods, the itching goes away, BUT not until it all leaves through my SWEAT pores, =(. The best way to get rid of them is to exercise until you sweat, and then you water yourself down with the hose. Get a good sweat going, and the pores will open, and once they are, the pain dissipates. Then you wash all the histamines off, and your good to go. JUST DON'T eat anything high in histamines, especially pizza, EVER, because you will pay dearly! I hope your son gets better.