Food allergy management and prevention — formative SAQs

SAQ 1 — Manage the reaction (10 marks)

A six-year-old with known peanut allergy and mild asthma develops lip swelling, widespread urticaria, wheeze and drowsiness within five minutes of eating a biscuit at a party. A carer has a 0.15 mg adrenaline autoinjector. [14] [6]

Questions

1. Outline the immediate management of this reaction and the rationale for each step. (4 marks) [14]
2. State the weight-banded adrenaline dosing approach and when to repeat it. (2 marks) [14]
3. Describe the disposition and observation plan, including the biphasic risk. (2 marks) [14] [6]
4. Outline the written action plan and equipment the family should leave with. (2 marks) [6] [14]

Model answer

Immediate management (4). Call for help. IM adrenaline into the anterolateral thigh as the first drug — do not wait for antihistamines or IV access. Lie flat with legs elevated if shocked; high-flow oxygen; IV fluids for shock; bronchodilator adjunctive for wheeze. Reassess ABCDE continuously. [14]

Dosing and repeat (2). Roughly 0.01 mg/kg of 1:1000 (1 mg/mL) IM; autoinjector doses 0.15 mg for smaller children (under ~20 kg) and 0.30 mg for larger (~20 kg and over). Repeat after 5 minutes if no response. [14]

Disposition (2). Observe for biphasic reaction — at least 6 hours for moderate reactions. Admit this child because of co-existing asthma and the severe initial reaction, and because more than one adrenaline dose may be needed. [14] [6]

Action plan and equipment (2). Personalised written anaphylaxis action plan (ASCIA/BSACI/FARE) with photo, allergen, dose and stepwise response; two adrenaline autoinjectors by weight; medical-alert identification; school/childcare plan and staff training. [6] [14]

SAQ 2 — Prevent the next case (10 marks)

A four-month-old has severe early-onset eczema. The parents ask whether to delay allergenic foods to prevent allergy. They have read conflicting advice online. [1] [4] [13]

Questions

1. State the current prevention advice and the evidence that overturned the old "delay solids" approach. (4 marks) [1] [2]
2. Describe the risk-stratified approach to introducing peanut in this high-risk infant. (3 marks) [1] [4]
3. Name two principles of early introduction beyond peanut, and one practice to avoid. (3 marks) [9] [13]

Model answer

Evidence (4). Delayed introduction increases, not reduces, allergy risk. The LEAP trial showed early, sustained peanut consumption in high-risk infants reduced peanut allergy by roughly 80% relative risk. LEAP-ON showed tolerance largely persisted after stopping. The Ierodiakonou meta-analysis and PETIT (egg) support early introduction. Old "delay solids" advice (e.g. pre-2010 NIAID) is superseded. [1] [2]

Risk-stratified peanut (3). Severe eczema and/or egg allergy defines the high-risk infant. Perform a skin-prick test (or specific IgE) first. If low or negative, introduce peanut around 4–6 months and sustain it. If positive, arrange specialist-led introduction or supervised challenge. Do not introduce peanut at home if testing suggests likely allergy. [1] [4]

Principles and pitfall (3). Introduce common allergens (egg, milk, wheat, fish, sesame) around 4–6 months and keep them in the diet regularly (sustained intake). Do not restrict the maternal diet during pregnancy or lactation; continue breastfeeding. The pitfall to avoid is over-restricting the infant's diet based on sensitisation rather than a confirmed reaction. [9] [13]