Copperhead snakebites: clinical severity of local effects

We sought to evaluate the type and extent of local reactions after copperhead snakebites.

We performed a retrospective evaluation of copperhead snakebites in West Virginia between January 1, 1995, and September 30, 1999. A local effect scoring system was used to define a clinically significant local reaction. A bite was considered clinically significant if the bitten individual's average local effect score was 3 to 4 (range, 0 to 4).

Ninety-two patients met the inclusion criteria; an average local effect score of 3 to 4 was documented in 33% (n=30). The foot was the most common bite location (46% of all bites); 87.5% of bites to the finger (n=8) resulted in a score of 3 to 4. Eight (36%) of 22 patients who presented to the emergency department within 2 hours of a bite and whose highest local effect score was 3 to 4 did not have their highest score until greater than 4 hours after the bite. The average length of stay (score 3 to 4) was 3.4 days compared with 1.1 days for those with a score of 3 or less.

Clinically significant local effects (eg, pain requiring parenteral analgesics, ecchymosis, swelling of over one half of the bitten extremity) occurred in one third of patients in our study. The generalization of copperhead snakebites as mild or of benign clinical significance should be reconsidered.