Background: The bite of the Loxosceles spider is a public health problem around the world, mainly in Latin America. The viscerocutaneous presentation is related to the inoculation of toxins (phospholipase-D) that generates a systemic inflammatory reaction with a subsequent increase in cytokines and chemokines. Hemoadsorption is proposed as a therapy that allows for the removal of the toxin and modulation of the inflammatory response in this disease. Case Report: We present the case of a 31-year-old woman who was admitted to the hospital due to decreased urinary flow and jaundice 48 h after a spider bite. Despite treatment with intravenous (IV) monovalent antiloxoscelism serum, antibiotic therapy, and corticosteroids, the patient’s evolution was poor, and she was admitted to the critical care unit for severe multi-organ involvement, including hepatic and kidney damage and coagulation disorders, eventually requiring hemodialysis support and hemoadsorption therapy. After the therapy was administered, rapid improvement was evident with the suspension of vasopressor support and a decrease in inflammatory markers. Conclusions: This case presents hemoadsorption as a therapeutic option, based on its capacity to reduce the intensity of hyperinflammation and to regulate the immunological response.

Background: Idiopathic hypereosinophilic syndrome (IHES) is a disorder characterized by abnormal and persistent peripheral blood hypereosinophilia (eosinophil count ≥ 1.5 × 10⁹/L and ≥10% eosinophils) with duration ≥ 6 months, associated organ damage, and/or dysfunction attributable to tissue eosinophilic infiltrate of unknown cause. IHES affects different organs such as the heart, lungs, nervous system, and skin, with renal involvement being rare in this condition. Case Presentation: We present a case of a young patient with IHES and immune complex-mediated membranoproliferative glomerulonephritis with nephrotic syndrome, as a rare renal manifestation. We discuss the clinical, analytical, and histopathologic renal and hematologic features, comparing them with other reported cases in the literature.