How should I approach the management of a patient with a suspected food allergy who has experienced anaphylaxis?

Immediate management: Treat suspected anaphylaxis as a medical emergency. Call an ambulance immediately and assess the patient using the ABCDE (Airway, Breathing, Circulation, Disability, Exposure) approach. Look for airway obstruction, breathing difficulties, and signs of circulatory collapse. If the patient is unresponsive and not breathing normally, start CPR immediately. Place the patient in a comfortable position—lying flat with leg elevation if hypotensive, or semi-recumbent if breathing is difficult. Do not allow the patient to stand or walk during the acute reaction as this may be fatal.

Adrenaline administration: Administer intramuscular adrenaline 1:1000 promptly into the anterolateral thigh. Repeat every 5 minutes if there is no improvement, up to two doses initially, then continue as needed until adequate response. Do not delay adrenaline administration or substitute with intravenous adrenaline in primary care settings. Remove the trigger if possible but do not delay treatment to do so.

Supportive care: Provide high-flow oxygen if available and monitor vital signs continuously. If hypotension or shock persists, establish intravenous access and give rapid fluid boluses (500–1000 mL in adults or 10 mL/kg in children). Consider inhaled bronchodilators if wheezing is present, especially in patients with asthma, but do not use them as a substitute for adrenaline.

Post-emergency care: After stabilization, observe adults for 6 to 12 hours depending on response; children should be admitted under paediatric care. Provide the patient (or carers) with education on anaphylaxis recognition, adrenaline auto-injector use (including a brand-specific demonstration), and the importance of carrying two adrenaline auto-injectors at all times. Advise on allergen avoidance and provide written individualized allergy management plans.

Referral and follow-up: Arrange urgent referral to a specialist allergy service for further investigation, diagnosis, and ongoing management. Offer interim prescription of adrenaline auto-injectors before specialist review. Consider mast cell tryptase blood tests soon after the reaction to support diagnosis. Ensure comorbid conditions such as asthma, eczema, and allergic rhinitis are optimally managed. Annual review is recommended to reassess allergy status, dietary intake, and risk of anaphylaxis.