pet lovers or vet techs- i need advice

yourfaceyourface

i have a beagle with pretty sensitive skin. is it possible for them to be allergic to fleas? i put flea stuff on her regularly beginning late winter to try and prevent this but once she gets outside and plays in the grass  her skin turns red and blisters and she gnaws it raw. poor girl is miserable.

the vet doesnt seem to know what exactly causes it and the only thing we have found to help it is prednisone. she is also on phenobarb for seizures.

so two questions: any idea on the skin thing or how to help it? and is the repeated doses of pred and phenobarb going to harm her liver?

tia!