Fever of unknown origin in a dialysis patient: A case report of dialyzer membrane allergy

Fever following hemodialysis presents a diagnostic challenge, often raising concerns about infection. However, non-infectious causes, such as allergic reactions to dialysis membranes, must also be considered. Dialyzer-related reactions, particularly to synthetic membranes like polysulfone, are increasingly recognized as contributors to post-dialysis fever. Although modern dialysis technology has improved biocompatibility by eliminating acetate buffers and sterilizing ethylene oxide, acute hypersensitivity reactions still occur. These reactions are classified into Type A (anaphylactic) and Type B (non-anaphylactic), each with distinct symptoms. Proper identification of these reactions is essential for management, as switching to a more biocompatible membrane is often required. This case report describes a 38-year-old male who developed a fever after hemodialysis in a prison facility. Initial workup ruled out infection, with negative blood cultures and elevated IgE levels suggesting a hypersensitivity reaction to the polysulfone membrane. The patient's symptoms resolved following a switch to a hypoallergenic dialyzer.