An anaphylactic reaction without skin manifestations after general anesthesia induction: a case report.

Anaphylaxis is a severe, potentially life-threatening hypersensitivity reaction. Although anaphylaxis rarely occurs during dental anesthesia, preparation for a prompt and appropriate response is crucial. Severe anaphylaxis may occur in the absence of typical skin manifestations. We encountered anaphylaxis approximately 15 min after induction of general anesthesia, presenting with a gradual decrease in SpO2, acute hypotension, and tachycardia without skin manifestations. After administration of epinephrine, the patient's hemodynamic status improved rapidly. Elevated serum tryptase and plasma histamine levels supported this diagnosis. This case highlights the diagnostic challenges of perioperative anaphylaxis during general anesthesia because cutaneous manifestations may be absent and alternative causes of hypoxemia or circulatory collapse must also be considered. Perioperative anaphylaxis remains an important differential diagnosis, even in the absence of skin symptoms. Prompt exclusion of alternative causes and early epinephrine administration are essential for successful management. Postoperative allergological evaluation, patient education, and institutional preparedness are important for reducing the risk of recurrence and improving patient safety.