How long does the itch in chicken pox last?

Oh dear - yes the itching gets worse when the spots dry out and continues until three days after the last spot appears - day 6ish. Have you considered anti-histamine tablets? My daughter took those and it helped loads. The incubation period is three weeks but your son would have been contagious before he had spots - so yes 14 days. It is so much better to have it as a child tho - I had it at 26 and got pneumonia and lost the hearing in one ear. Good luck.