Anaphylactic Shock Probably due to a Cross-Reaction Between Cefuroxime and Piperacillin-Presentation of a Fatal Case, Diagnostic Considerations, and Literature Review.

Although beta-lactam antibiotics are widely used in intensive care, rare but potentially fatal anaphylactic reactions can occur due to cross-reactions between penicillins and cephalosporins. We report the case of a 68-year-old man who suffered perioperative cardiac arrest following the administration of cefuroxime. During the postoperative period, the patient received ampicillin/sulbactam without any signs of hypersensitivity. Following a switch to piperacillin/tazobactam prior to a procedure, the patient suddenly developed cardiovascular arrest and died. The autopsy revealed no macroscopic cause of death, but immunohistochemistry showed mast cell degranulation ("starry sky pattern") in the tissue, suggesting anaphylaxis. We present the clinical and histopathological findings of a case with severe allergic reactions to both cefuroxime and piperacillin/tazobactam, as a result of either cross-reaction or isolated sensitization to both antibiotics. This case report highlights the potential risks of cross-reactivity between beta-lactam antibiotics and the importance of autopsy in ambiguous cases. Clinicians should be aware of cross-reactivity or cosensitization to multiple beta-lactams in patients with a beta-lactam allergy and consider non-beta-lactam alternatives in high-risk cases.