Just curious but have you had chicken pox as a child? Most people have but a few escape it.
I got it when I was 16 years old which is unusually late. I can well remember the sores driving me nuts itching and I have scars on my behuind from scratching them.
(More info than you wanted to know I bet)
I think I did when I was little. Now I am curious, so I will have to ask my mother.