Normal
As for having allergic reaction to tarantula venom,may I put a hypothesis forward that is so simple and has been overlooked. You can't get an allergic reaction from a tarantulas venom, what about whats attached to the fangs outside which pierces the skin ? Meaning,something it digested or got in contact prior to biting you that conflicts with your own body ? Say a feeder,it has been brought up on say bananas and that means that feeders juices contain banana traces(person has an allergic reaction to bananas)doesn't seem significant but take into consideration the epidermis and even deeper gets pierced with those trace amounts and directly enters the blood stream what now ? Or a microscopic bug,or virus your body will fight it off or try while you think you're having an allergic reaction your immune system is having a war. This is firstly a hypothesis,and secondly an example using the banana so take it for what it is.