I too used to get it bad. I swear I spent half my childhood with it. The most uncomfy places I had it were mouth, eyelids(even inside the eyelid once or twice), between the fingers, and genitals. My fingers would swell so much I couldn't make a fist or the skin would split. Somehow it spread to my urethra once. Nothing like itching inside your penis and not being able to pee when you have to, to put a damper on your day. I used to go to the doc to get some kind of steroid shot. They gave me pills too but the pills take 2-3days to start working and the shot starts helping the first day.
Sometime in my late teens I developed a bit of an immunity to it. I can still get it but for the first time in my life my body fights it off on its own without meds. In fact my last visit was to the doc to get a shot for poison ivy about 17yrs ago...haven't needed the doc since then. Now when I get it its usually a pretty small patch and doesn't spread unless I scratch it.
Now I found our I'm allergic to asian ant species. One bite and I itch for weeks.