Can allergies cause flu-like symptoms??

[care]

I woke up yeaterday with VERY sore throat, a VERY painful cough and just fely like crap....Today I've been fatigued, low grade fever (99.1) and achey...I went to my college's doctor, and she listen to my lungs and explained to me that it's [rpbably my bosy's reaction the the first symptoms of my seasonal allergies(the trees nd grass are just beginning to bud here)...She explained that nasal drippage can drip down to my throat and lungs causing pain in my throat and lungs and coughing....makes sense--but I thought allergies had NOTHING to do with a low grade fever/chills/body aches....She put me on allegra and asked me to come back in 3 days if there is no imporovement......my question is it possible that this could be correct?? Thank you very much...