unfortunately spider bites have a tendency to cause infection and i believe we may be at this point in this situation. this could be the start of cellulitis which is a bad skin infection. i would advise seeing a health care provider as soon as possible. an antihistamine like benadryl will not help.
i was bitten by a spider on the inside of my forearm and now it is very swollen red and painful. will benadryl help?