Local morbidity from red-bellied black snake (Pseudechis porphyriacus, Elapidae) envenoming: Two cases and a brief review of management.

The red-bellied black snake (Pseudechis porphyriacus, Elapidae) is one of several species of venomous snakes most commonly implicated in human and domestic animal envenoming in Australia. Human systemic envenoming can present with myotoxicity that may include myoglobinuria; hemoglobinuria and intravascular hemolysis; thrombocytopenia, anticoagulant coagulopathy, and, rarely, mild cranial nerve palsies. Pseudechis porphyriacus envenoming can also feature significant local morbidity such as ecchymoses, bleeding, pain and necrosis. Some envenomed patients may develop progressive thickness necrosis independent of secondary infection, and occasionally require surgical debridement. Uncommonly, some digital envenoming may cause more severe deeper tissue pathology that justifies dermotomy and/or distal phalangeal amputation. Presented are two patients with significant local morbidity from P. porphyriacus envenoming. An 18-month old girl received a protracted envenoming on her right foot, while a 38-year old male professional zoologist was envenomed on the third digit of his right hand. Each patient experienced myotoxicity, one had anticoagulant coagulopathy, and both developed clinically significant local morbidity including persistent bleeding, ecchymoses, local necrosis and pain; each required extensive treatment and variably prolonged admission. Noted also were transiently elevated D-dimer with low-normal or normal fibrinogen levels. The progressive necrosis and subsequent chronic pathologic changes with ischemia of the latter patient's digit eventually required a dermotomy and amputation of the distal phalanx. The pediatric patient did not require extensive wound debridement, but experienced prolonged difficulty in ambulation because of slowly resolving wound discomfort. Factors that may contribute to the severity of local morbidity of P. porphyriacus envenoming are considered, and management of envenoming by this taxon is briefly reviewed.