It seems that most probably your son may be having sebaceous cysts.
Also called epithelioid cysts.
The are benign cysts and harmless.
Do not try to squeez. Otherwise they may be infected.Consult dermatologist
. He may excise the cyst under local anaesthesia.
It is minor surgery,done in OPD.
I hope you got my answer.
Dr. Ilyas Patel MD