How to tell the difference between flea bites and hives?

I'm not sure if I'm getting hives from strawberries and chocolate OR if I am getting bit by fleas. I bathed our dogs with flea shampoo but there was only one flea on one of the dogs. No one else in family has gotten bit and I haven't found any other fleas in the house to be honest. Everyone pointed out that every time I eat chocolate and/or strawberries I get them. Any way to know for sure? I never had allergies as a kid.