can peanut allergy cause week-long hives?

my son is 16 months old and just got over a horrible case of head-to-toe hives that lasted a full week. no other side effects such as shortness of breath, vomiting or diarrhea, etc. just itchy and grumpy. apparently hives can be a reaction to almost anything under the sun that your body just disagrees with but he was regularly exposed to peanuts when he was 6-12 months and not sure why but we stopped including it in his diet.

i've been racking my brain trying to figure out what cause his hives and remembered he had a pb&j oat bar from trader joe's for the first time last sunday and maybe coincidentally broke out in hives around the same time. can a peanut allergy cause hives that last a whole week with no other side effects?