Bite marks are useful for the differential diagnosis of snakebite in Brazil.

Abstract

To assess whether examination of the bite marks could be useful for the differential diagnosis between venomous and nonvenomous snakebite. Assessment of the validityof the bite marks in the differential diagnosis betweenvenomous and nonvenomous snakebite in a series of patients prospectively recruited in a 32-month period. Teaching hospital in a southeastern Brazilian town. Forty-two victims of snakebite who brought the captured or dead snake for identification and who had recognizable bite marks. Inspection of the bite site, recording the aspect of the marks either as isolated fang punctures or as multiple scratch-like teeth marks. The presence of isolated fang marks, when related to venomous snakebite, had a sensitivity of 100%, a specificity of 56%, and a predictive value of 89%. The finding of multiple, scratch-like teeth marks had a predictive value of 100% when related to nonvenomous snake bite. Examination of the bite marks showed to be useful for the differential diagnosis between venomous and nonvenomous snakebites in Brazil, which has implications for the option of empirical administration of antivenin to patients when the snake is not available for identification.