Baby waking up with stuffy nose

[iamverytired]

I can't work out why but my 7 month old has recently been rubbing his nose like it's itchy (we have lots of food intolerances but this is new) and when he is put down in his own cot he wakes after an hour or two with a blocked nose. I take him into my room to cosleep after approx 11pm if he won't resettle and it doesn't happen in there. Maybe because he sleeps face down in his cot and more on his side next to me? He has developed eczema recently too - I've cut fabric conditioner etc. The room isn't dusty or mouldy that I know of. It is a small room though so maybe circulation isn't that great when I pull the door too.
Any suggestions?

Hay fever? Pollen could be coming in from the window or on the bedsheets if you dry them outside or just general pollen build up from during the day hits when he lies down.

You can prop the head end of the cot up so he's sleeping on a slight incline which should help the stuffy nose.

I think you'd need to see a doctor for hayfever meds for an under one.

Thanks that could definitely be a possibility! I've stuck an air purifier on to see if that helps!