This group will undergo a detailed penicillin allergy evaluation performed by an Infectious Diseases specialist. Patients with negative result in skin test and oral provocation test will have their prior labelled penicillin allergy removed from electronic health record, and an additional entry documenting the negative allergy evaluation will be added. A letter signed by an infectious disease specialist documenting the allergy evaluation results will also be given to patients.

This group will receive standard perioperative care. The choice of antibiotics during the perioperative period will be decided by surgical team.

The intervention group will undergo a detailed penicillin allergy evaluation performed by an Infectious Diseases specialist. Components of penicillin allergy evaluation include verification of allergy history (drug involved including dose and route of administration, exact manifestation of labelled allergy and timing of occurrence after use of alleged culprit, history of skin tests or in vitro testing for diagnosis of allergy, subsequent rechallenge of the same or similar antibiotics), followed by skin test (prick test and intradermal test) and oral provocation test as appropriate.

The primary endpoint is use of first-line antibiotic for surgical prophylaxis according to local guideline .

Antibiotic related adverse events include: 1) any new symptoms reported by patients, or 2) abnormalities in blood tests that are compatible with known side effects of antibiotics given and that occurred after initiation of antibiotics.