Egg, wheat, soy, fish and shellfish allergy: Viva

Branch 1: Recognising and treating the acute event

The candidate should immediately recognise this as food-induced anaphylaxis. The rapid onset of urticaria with wheeze and hypotension minutes after eating a known allergen meets the clinical criteria for anaphylaxis, and the first action is intramuscular adrenaline into the anterolateral thigh. The single most important teaching point is that adrenaline must not be delayed for antihistamines, bronchodilators or observation, and that the combination of food allergy with uncontrolled asthma marks this boy as high-risk for a fatal outcome. ^[2]

The dose is the weight-appropriate autoinjector dose: at 14 years he is likely over 20 kg, so the 0.3 mg device is used, repeated after five minutes if there is no response. Adjuncts include high-flow oxygen, an inhaled bronchodilator for persistent wheeze, intravenous isotonic fluid for shock, and supine positioning with legs raised. The candidate should state that he needs hospital observation for a biphasic reaction, which can recur four to thirty hours later, and discharge with an adrenaline autoinjector, an action plan and allergy follow-up. ^[2]