Loxosceles venom-induced cytokine activation, hemolysis, and acute kidney injury

Herein, we describe a confirmed case of Loxosceles spider bite that illustrates the critical complications seen in loxoscelism, including skin necrosis, rhabdomyolysis, hemolysis, coagulopathy, acute kidney failure, and electrolyte disorders. Upon initial assessment, laboratory studies revealed the following: the white blood cell count was 29 400 WBCs/mm3, hemoglobin was 9.2 g/dL, and the platelet count was 218 000 cells/mm3. Coagulation studies revealed the following: international normalized ratio, 1.83; activated partial-thromboplastin time, 62 s; D-dimer, 600 ng/mL (normal range <500 ng/mL); free protein S, 37% (normal range=64–114%); protein C, negative; and antithrombin III, negative. Various serum levels were abnormal: urea, 110 mg/dL; creatinine, 3.1 mg/dL; indirect bilirubin, 3.8 mg/dL; creatine kinase, 1631 U/L; lactate dehydrogenase, 6591 U/L; potassium 6.2 mmol/L. Urine tests were positive for hemoglobin and bilirubin. In addition, concentrations of interleukin-6 and tumor necrosis factor-α were notably elevated in the serum. In conclusion, physicians must be alert to the possibility of loxoscelism when a patient presents with the clinical and laboratory findings described above, especially if the patient resides in an endemic area. Advances in our understanding of multiple pathways and mediators that orchestrate the response to Loxosceles venom might reveal new possibilities for the management of loxoscelism.