skin condition

Question
I have a two and a half year old female boxer. I ran out of her regular dog food on Saturday, so I just bought a small bag of Dads. Normally she eats Purina High Pro, as her previous owner says that she has an allergy (makes her extra itchy) to eat most dog foods that have corn as the main ingredient. Anyways, Saturday evening I noticed small lumps starting to form all over her body and she was itching like crazy. I didn't give her anymore and went to the other store and got her regular food. I am not sure if the lumps appearing are related to the food change. Can dogs get a reaction like that from an allergy? I gave her a flea bath right away and started her on Benedryl. It is now Monday and she looks a bit better, but she still has lots of lumps. They are under the fur (no hair loss). Any suggestions?

Answer
Sounds like hives my boston terrier had lots of them on her lightly haird area by her butt and inside her thigs when he allergies started since chaning to a fish and potatoe hypo allergtic kibble(Blue Buffalo Co.) and putting her on Benadryl as well she is going great the bumps went away shortly aftr I began treatment so you can expect them to go away sometime soon.