4.5 mo with hayfever???

DD is now 4.5 months and this is about the 3rd real time she is showing signs of hayfever. Everything online says kids don't get hayfever or allergies till they are 3 years old but to me it looks like she has hayfever, and bad..

She is sneezing ALOT, runny nose, no temp, red blotchy face which comes & goes, sometimes swollen eyes, eyes are watering all the time. I had this happen at about 3 months of age, and one day her eyes were so swollen and red so I took her the Dr. He essentially said that it was looking and presenting like hayfever but due to her age they would not diagnose it as that as she is too young. He said as I have it, DD1 has it and DH gets it then it is obviously a hereditary thing also.

Last night she was REALLY snuffly and today the sneezing has been pretty constant with watering red eyes and she has only been sleeping for 1 x 40 min cycle and seems a little unsettled/unhappy. She never has a temp when it's like this.

Has anyone else experienced this and if so what did you do? I know that if it is hayfever that there is nothing they can give her specifically for hayfever to treat it but i feel bad for her because i get hayfever all year round and i know how miserable it can make you feel.