Help! I have diaper rash but I've never worn a diaper?!

you have pin worms.
go to the pharmacy, and ask for this drug(no prescription needed):Pyrantel Pamoate
read the instructions:this drug is given by weight.
de-worm yourself and everyone in the same house with you.
repeat in 3weeks.
all bedding, towels, clothing to be washed and dried at a high temperature,otherwise you re-infect yourself.
the eggs of the worms can be all over you clothing, bed sheets etc.
its not from dogs or cats:these worms live in humans only.

Ah, so not a rash, but parasitic worms. Those are pretty different things. Ya. Doctor.