I've had chronic idiopathic urticaria for years, to varying degrees. Hives are a common side effect to many things (which sucks, because it's such an incredibly

I've had chronic idiopathic urticaria for years, to varying degrees. Hives are a common side effect to many things (which sucks, because it's such an incredibly aggravating symptom). It's possible the vaccine is the cause of yours, and the timing makes sense, but it can happen entirely randomly, and that's the case for at least some people who started experiencing hives alongside their shot. I couldn't stand the drowsy effect from Benadryl. Your friend might want to give Fexofenadine (Allegra / Allerfex) a try, it's just as effective for me and doesn't result in that "head empty" feeling. Loratadine (Claritin) might also work. Costco sells both in bulk generic quantities and they're cheap compared to the branded stuff.