I wanna say spider bite as well. brown recluse? not too sure. all the times ive heard of brown recluse bites, the area around the bite SWELLS UP and they the victim experiences pain and their venom is tissue destroyer so basically it's like seeing your own skin dissolve. as to whether that happens with every bite or only severe cases, im not too sure but im just going by what ive seen/read but yes you should definitely see a doctor.