I am 32 years old and have EHK. I have spent years tracking the peeling cycle that I have found in myself, paticularly after a fever.
My palms and soles peel (callouses and everything) about 1 days or so after a fever. My doctor said that it might be an allergic reaction that normally does not show itself but becomes apparent during a fever.
I actually got sick on purpose so that I would have a nice peel before my wedding. I managed to time it perfectly and have wonderful wedding photos.
Track your sons peels and see if you can find a pattern, I know it happens. Perhaps it is our bodies way of refreshing itself!

Sarah & Son
"Today is the Tomorrow that you worried about Yesterday, and all is well"