Copperhead envenomations: clinical profiles of three different subspecies

Copperhead envenomation cases reported in the literature frequently lack identification of the subspecies of copperhead responsible for the envenomation. Whether subspecific identity would be useful in predicting possible different toxicity profiles may have clinical relevance. We report here the clinical profiles from envenomations involving 3 different subspecies of captive adult copperhead snakes--the southern copperhead (Agkistrodon contortrix contortrix), the northern copperhead (Agkistrodon contortrix mokasen), and the broad-banded copperhead (Agkistrodon contortrix laticinctus). The bites occurred in the north-central region of the US where none of these subspecies are endemic and involved a professional and 2 amateur herpetologists. The victims were adult males with no previous history of venomous snake bite, and all bites were evidenced by fang puncture marks to their index finger or thumb. Envenomations from the broad-banded and northern copperhead subspecies caused localized symptoms of pain, edema and ecchymosis. In addition to these symptoms, southern copperhead envenomation resulted in a more severe clinical toxicity profile as evidenced by propulsive emesis, diarrhea and hematuria. Whether these differences in observed clinical toxicity were the result of unique subspecific venom pharmacological actions is an interesting question. However, independent of the copperhead subspecies involved, conservative medical management was effective in each case.