Medical algorithms: Diagnosis and investigation of perioperative immediate hypersensitivity reactions.

A systematic approach to both diagnosis and investigations is essential, when investigating a patient with a suspected perioperative hypersensitivity reaction. The perioperative setting is extremely complex with documented and undocumented exposures to many different drugs and substances. In addition, the effect of anaesthetic drugs and surgical procedure may mimick hypersensitivity. To ensure that all these complexities are addressed, collaboration between allergist and anaesthetist is essential. Also, the current recommendation is, that investigation of these patients should take place in highly specialized centres or in centres investigating a minimum of 20 patients/year, and where close collaboration between allergists and anaesthetists is established.