A Rare Case of Micro-Angiopathic Hemolytic Anemia Due to Envenoming by Giant Asian Honey Bee (Apis dorsata)

Giant Asian honey bee sting envenoming is a recognized cause of morbidity and mortality in rural Sri Lanka. Mass envenoming causes clinical effects, either as allergic and anaphylactic reactions or bee sting toxin-induced multiorgan damage. We report a patient who had mass envenoming from more than 1000 stingers who subsequently developed hematologic features suggestive of thrombotic microangiopathy-related hemolytic anemia. The transient acute kidney injury and acute hepatic failure seen in the patient were also considered to be secondary to thrombotic microangiopathy. A normal clotting profile and a high proportion of schistocytes in blood film ruled out disseminated intravascular coagulation as the underlying cause of the microangiopathic hemolytic anemia. The normal platelet count raised the possibility of a "partial" thrombotic microangiopathy, as has previously been reported in association with Shiga toxin-related hemolytic uremic syndrome and hump-nosed pit viper envenoming. Venom-induced direct toxicity on red cells was another possible explanation for the hemolysis, but the high proportion of schistocytes made it less likely. The place of therapeutic plasma exchange for venom-associated thrombotic microangiopathy is controversial. The patient recovered with symptomatic treatment and meticulous fluid management, without needing therapeutic plasma exchange as an adjunct treatment.