Perioperative anaphylaxis may lead to fatal respiratory and/or circulatory events, yet both clinical diagnosis and management are challenging. Serum tryptase is an indicator that can provide important retrospective diagnostic value for anaphylaxis. Another key point in perioperative anaphylaxis management is to identify the allergens, and thus avoid re-exposure during later perioperative management. Skin testing is an important way to identify allergens.

Perioperative anaphylaxis are rare, but may be fatal. The combined use of anesthetic drugs and other medications, and the additional effects of surgical procedures, make the diagnosis and differential diagnosis rather complicated. Subsequent allergy investigations and allergen identification are often difficult.

The change of tryptase levels is an important biomarker in differentiating anaphylaxis from other causes. It is recommended that, in case of any suspicion of perioperative anaphylaxis, serum samples for tryptase detection should be collected as soon as possible after the onset of symptoms and then repeated 24 h later. Skin testing including skin prick tests (SPT) and intradermal tests (IDT) is universally used in identifying allergens. Skin testing will be performed 4-6 weeks after the onset of perioperative anaphylaxis.

This prospective cohort study is designed to clarify the rate of perioperative anaphylaxis with testing serum tryptase level and to identify the underlying allergens by conducting skin testing in surgical patients with suspected perioperative anaphylaxis.

Inclusion Criteria:

• Aged 2 years or over;
• Suspected anaphylaxis in the operating rooms, or history of suspected anaphylaxis in the operating room.

Exclusion Criteria:

• Refuse to participate;
• Other conditions that are considered unsuitable for study participation.

Patients with suspected anaphylaxis in the operating room.