All over rash

[StealthPolarBear]

My 15mo had a high fever yesterday (when I took it it was over 39, and think it had come down by then), start of a rash on his neck and was generally unwell.
Gave him calpol at 7pm and his temp came down, he seemed much better.
Today he is still OK, temp fine but blotchy rash has spread all over his body. He is slightly more clingy / grouchy than usual but on the whole is alert, happy, running around etc. Eating as well as he ever does.
Do we need to worry? It passes the glass test (though i have my reservations about that), haven't changed washing powder. He had MMR about 2 and a half weeks ago (if you read my other thread, i was a week out!!)

[StealthPolarBear]

bump
should mention he has had a couple of diarrhoea type nappies but not full blown diarrhoea (i.e. every nappy, and very runny)

[StealthPolarBear]

thank you, that's reassuring
TBH I'm not too worried as he doesn't seem ill, but then I'm worrying that I'm not worried iyswim