Have just finally got DS age 5 and in reception back to sleep after a 2 hour bout of coughing. He coughed for two hours at bedtime meaning he didn't get to sleep until gone 9pm and was up again at 2am. He woke up on Monday morning complaining of sore throat and his glands were very swollen. I kept him.home (am SAHM to him and 1 year old DD) and by 5pm he had a raging temperature and foul cold. DD has been unwell since Friday night and I finally succumbed on Monday night as well, although I seem to be mending a lot quicker. He barely ate on Tuesday and temperature was up and down all day and night. His temperature has stabilised today (Wednesday) but now he's coughing and awake. In my addled state (as he was pretty chipper during the day so hoped he would be ok to go to school on Thursday) I don't know if I'm being over-cautious keeping him home or cruel sending him in!
He's a skinny scrap and very susceptible to bugs etc (is a ruddy picky eater, and I just can't seem to get him built up).
I'd also keep him off OP. My DS (also 5) is prone to getting chesty coughs with a cold, and can have a few nights of very little sleep as a result.
I used to keep him off pre-school when he was like this, but felt bad keeping him off once he started school as he was generally ok during the day when like this. So sent him in... and got a call from school 2 hours later to say he had been sick from coughing so much I felt awful.
He's only 5, he'll catch up. Hope he's better soon (and you manage to catch up on some sleep!)