Peanut, tree-nut and seed allergy — branching viva

Opening (2–3 minutes)

Examiner: This child has peanut allergy and asthma. How will you frame the consultation for the family? [3]

Strong answer: I would confirm the diagnosis is challenge-confirmed or based on a clear history with supportive testing, reassure the family that the plan is built around keeping her safe rather than only restricting her, and signal that we will address three things: whether she will outgrow it, whether all nuts must be avoided, and whether immunotherapy is appropriate. I would also note that her asthma must be well controlled, because asthma is the strongest risk factor for fatal food anaphylaxis. [3]

Branch A — Natural history

Examiner: Will she outgrow it? [3]

Strong answer: Peanut allergy resolves in only about one in five children by school age, so the working assumption is persistence. Falling peanut-specific IgE and Ara h 2 over time predict resolution, and a supervised oral food challenge confirms it. I would offer serial testing and, when titres fall, a challenge rather than assuming lifelong allergy or, conversely, assuming resolution. [3]

Branch B — Avoiding all nuts?

Examiner: Should the family avoid all nuts? [14]

Strong answer: No. Avoidance should be specific to the clinically reactive food. Peanut cross-reacts with tree nuts more than chance would predict, but each nut is assessed on its own merits with component testing or supervised challenge. Blanket avoidance is unnecessarily restrictive, harms nutrition and quality of life, and is a recognised pitfall. I confirm each nut individually before restricting it. [14]

Branch C — Immunotherapy

Examiner: They ask about 'the treatment that cures allergy'. What do you tell them? [6]

Strong answer: Peanut oral immunotherapy, shown in the PALISADE trial of AR101 and the IMPACT trial in young children, desensitises the majority of treated children — it raises the reaction threshold and protects against accidental exposure. It is not a cure: sustained tolerance is not established, and the treatment itself causes allergic reactions in a substantial minority and carries a risk of eosinophilic oesophagitis. It is a specialist-centred, shared-decision option for selected children, not a blanket recommendation. [6]

Branch D — Acute reaction

Examiner: She has a reaction at school. What is the first-line treatment and the common error? [12]

Strong answer: First-line treatment is intramuscular adrenaline into the anterolateral thigh, approximately 0.01 mg/kg, repeated every five minutes if features persist. The common error is delaying adrenaline for an antihistamine or observation. She should carry her action plan and at least one autoinjector, school staff must be trained, and her asthma must be optimised. [12]

Branch E — Prevention for a sibling

Examiner: The mother is pregnant. What do you advise for the next child? [1]

Strong answer: The LEAP trial showed that sustained early peanut introduction from four to six months in high-risk infants reduced peanut allergy by roughly 80 per cent. Given the family history, this infant is high-risk, so I would follow the NIAID addendum and ASCIA guidance: consider testing, then introduce age-appropriate peanut early and maintain regular consumption. [1]

Examiner scoring cues

Pass: challenge to confirm and serial IgE for natural history; specific not blanket avoidance; desensitisation vs cure distinction for immunotherapy; IM adrenaline first-line; LEAP prevention for the sibling. [3] [6] [12] Fail: assumes lifelong allergy without reassessment; blanket all-nut avoidance; presents immunotherapy as a cure; gives antihistamine first in anaphylaxis; cannot state the LEAP finding. [14]