Delayed antivenom treatment for a patient after envenomation by Crotalus atrox.

Bites by the Western diamondback rattlesnake (Crotalus atrox) are the most common cause of envenomation in Texas. We describe a patient who had delayed administration of antivenom after envenomation by C atrox. Because of an initial adverse response to a test dose, the patient had been unwilling to receive antivenom therapy. When compartment syndrome developed 52 hours after envenomation, however, the patient consented to antivenom therapy as an alternative to fasciotomy. We documented a decrease in compartment pressures and resolution of thrombocytopenia that was concomitant with antivenom administration.