4 yr old - temperature, rapid breathing, runny nose - again

[aliharris]

Has anyone else had experience of a toddler/child who has a runny nose probably 3 wks out of 4, but every few weeks gets worse for several days with a temperature and rapid breathing?
Calpol/Calprofen keep it under control, and he is generally OK in himself, only properly poorly for a day or so each time, although not well enough to go to nursery.
I just feel that it's more than a cold, have been to the drs on and off over the past couple of years, and each time his chest is clear (has had coughs too, but not for a couple of months now), had an inhaler to try but no improvement. Just get sent away with "it's a virus" . . .
Is there anything that I can ask the dr to check for?
Apart from the fact that he is poorly, I am supposed to be at work while he is at nursery and it's really difficult to keep saying, "sorry can't come in". Really want to get to the bottom of it.
All suggestions welcome.

No - at least, not for that long - but constant snotty nose could be dairy or other food intolerance? Just a wild stab in the dark if you feel something isn't right.

Yes could be, he was off cows milk til he was about 2, altho only symptoms of allergy was a (very impressive) rash which he hasn't had since. His nose is just clear runny, not thick snot. Would an allergy build up to resulting temperature do you think?

Unlikely the temperature is related to an allergy or intolerance (DD1 has CMP allergy so I know a little about the area) - that bit could just be the neverending cycle of colds. God knows my youngest is ill all the frigging time.