Won't wear a nappy and a rash???

[Locketjuice]

Pretty much that..
He's 1. Screams and crys, even waking him self up crying taking his nappy off and going back to sleep its not tight and have noticed as soon as he wees he's most likely to do it but if he remembers will before, I don't know if its related but he also has a viral rash all over his tummy/back down by his 'dinkle' and bum and dry patches... Help?

Don't know if they are related or if maybe he has a pee infection hence the crying

Should add went to the doctors yesterday for his injections but mentioned the rash had it checked and they said they will leave him injections until next week as he is clearly a bit snotty not really ill more just blurghhhhh