Hey KC,
I don't think peri can cause you have food allergies. You can just develop food allergies any time in your life. If it's food allergies, the hives would've gone away within 24 hours. Did the Benedryl help? If the hives are still hanging around, it is probably not food allergies but just.... HIVES!
I am the Queen of Food Allergies - allergic to 4 food groups (dairy, wheat, corn, legumes) and also have had hives many times in my life! And my hives have been EXTREME! With food allergies, I get congested and have to cough up. My hives come on for no reason at all and also if there's an extreme stressful situation that was happening to me. The hives don't go away with Benedryl either. It lasts a long, long time...hate it, esp. when I get it on my face. I can also how itchy you can get - had hives from head to toe, front and back! So, I know what you mean by being itchy!!!
Each person reacts differently to food allergies - someone who has a real severe allergy might have the throat closing in on them so don't worry yourself sick thinking that will happen to you - it can, but not necessarily! And if it were to happen, it would happen right when you're eating the food. I had that once only and it is scary!
Molly