how do you know it's hay fever?

[mom41]

My DD is 21 months and has red, watery eyes (but no gunk), runny nose (but it's clear) and is in a foul temper.
Neither I or DH suffer from allergies, so I was wondering if this sound like hey fever?
Thanks

it does, certainly the symptoms I get, including extremely itchy throat. Red eyes normally itchy too.

my dd is grump city and complaining of sore throat, I have the same symptoms, piriton helping.

Poor thing. I don't know if her throat and eyes itch. She's not coughing or sneezing more then usual and she doesn't seem to be rubbing her eyes a lot. Would it be OK to try the Piriton and see if the symptoms go away, or should I take her to Dr?
Sorry if I seem silly. First time mum and all...