It will depend on your dr obviously but I have heard big, splotchy hives on the chest or feeling your throat starting to close. If your not sure, it’s better to play it safe than not. Hope this helps.

So the hospital told me if I need to use Benadryl for a reaction that’s happening, I need to use the epi pen and come in to be safe. But I would talk to your doctor about that as well since everyone is different. I get really bad really fast in reactions and have stopped breathing a few times so I always use caution and just give the pen.

Best to speak with your doctor. I've read two or more body systems involved. It also depends on your baseline. There are a lot of ways that we react. My reactions change pattern so I can't go by what I did years ago. If in doubt it's best to err on the side of caution.