Bites by puff-adder (Bitis arietans) in Nigeria, and value of antivenom

Ten patients bitten by the puff-adder (Bitis arietans) were studied in the North of Nigeria. Six showed severe local signs, and four also had evidence of systemic envenoming, including spontaneous bleeding with thrombocytopenia, hypotension, and bradycardia. Two patients died after developing circulatory collapse and renal failure. Antivenom and intravenous fluid restored blood pressure in two hypotensive patients, and antivenom probably prevented the development of local necrosis in four others with massive local swelling. Victims of B arietans who have swelling of more than half the bitten limb or show signs of systemic envenoming should be given at least 80 ml of specific polyvalent antivenom and watched carefully for signs of circulatory collapse. Debridement of necrotic tissue may be necessary.