How do I know if my 4yo has hayfever?

[kid]

His eyes have been puffy for the past couple of days and today at nursery, they told me he hadn't been himself. He also said his head hurt.

He doesn't have a temperature or rash and did eat all of his lunch. His eyes do not itch and he doesn't have a runny nose. He gets enough sleep, from 8pm till 7am.

Do you think it could be hayfever? I haven't got a clue as neither DH, DD or I suffer from it.

could be, might be useful to try one day with an antihistamine, one day without, should then be able to see of it's heyfever or not. I've found Pharmacists are quite good at dishing out appropriate over the counter stuff.

Thanks for the suggestion teatimethatswhytime
I have some allerelief or something like that in the cupboard, I will give him some tomorrow and see if that makes a difference or not.

Dr doesn't think its hayfever as there aren't enough symptoms. His tonsils and glands are swollen so she is confident he is about to come down with something. After dinner tonight, he started getting a temperature so looks like the Dr was right.