An allergic reaction?
Seriously?
Do you now how astonishingly rare these are for venomous snakes in general? I mean people who work constantly around front fanged snakes run a slight risk due to the inhalation of dried venom residue or from repeated envenomations, but for rear fanged snakes they are all but unheard of.
Oh, I'm sure someone will rush to point me to the direction of a photo of a hognose bite victim, complete with swollen digits - but you realize this is from the venom - not an allergic reaction? Right?
You know what an allergic reaction is? What an allergic reaction is caused by?
Regardless - I would strongly suggest that you shot a PM to either Dr. Fry or Dr. Wuster and tell them of this unheard of and yet to be documented occurrence. Anaphylaxis and allergic reactions to colubrid bites are all but unheard of. There has been only one documented case of an allergic reaction and it did not involve a death.