Allergic disease in children: integrated approach: SAQ

This boy has multisystem atopic disease: early-onset severe eczema, challenge-or-history-confirmed peanut allergy with prior anaphylaxis, and now asthma and allergic rhinitis. He illustrates the atopic march in a single child, and his poor asthma control in the setting of food allergy places him in the highest-risk group for fatal anaphylaxis. The integrated task is to address all four organs with one coordinated plan, to confirm the peanut diagnosis with a supervised challenge when resolution is plausible, and to ensure he carries an adrenaline autoinjector with a written action plan. [5][7]

Question 1 (10 marks)

Classify this child's allergic disease by mechanism and by organ, explain the atopic march, and justify the adrenaline-autoinjector decision. (4 marks for mechanism and organ classification; 3 marks for the atopic march; 3 marks for the autoinjector decision.) [4]

By mechanism, his eczema is a non-IgE / mixed Th2-and-barrier disease, his peanut allergy with prior anaphylaxis is an IgE-mediated mast-cell disease, and his asthma and allergic rhinitis are chronic type-2 airway inflammatory diseases. By organ he has skin disease (eczema), gut disease (peanut allergy), lower-airway disease (asthma) and upper-airway disease (rhinitis). The mechanism classification matters because it determines the action plan: the IgE-mediated peanut allergy is the one for which adrenaline belongs in the plan, whereas the non-IgE diseases are not adrenaline-responsive. [4]

The atopic march describes the tendency for these diseases to appear in sequence in the same child: eczema and food allergy in infancy followed by allergic rhinitis and asthma in the pre-school and school years. This child is following the march in textbook fashion, beginning with early-onset severe eczema, which is the single strongest predictor of progression. The march is driven by shared type-2 biology: barrier breakdown allows transcutaneous sensitisation, interleukin-4 and interleukin-13 drive immunoglobulin E class switching, and interleukin-5 sustains the eosinophilia that underlies asthma. [5]

He should carry an adrenaline autoinjector. The indication is a prior anaphylactic reaction plus ongoing confirmed peanut allergy, and his poorly controlled asthma multiplies his fatality risk because the bronchospasm of anaphylaxis sits on top of a twitchy, undertreated airway. The plan is built around the worst-ever reaction, not the most recent; the prior anaphylaxis at 11 months is the defining event regardless of what has happened since. A written action plan, a loaded autoinjector, and school and carer education are all required. [7]

Question 2 (10 marks)

Outline the integrated stepwise management plan across all four organs, address the mother's question about whether the peanut allergy will resolve, and discuss whether oral immunotherapy should be considered. (4 marks for the integrated plan; 3 marks for natural history and re-challenge; 3 marks for the oral-immunotherapy shared decision.) [2]

The integrated plan runs three lanes in parallel. The prevention lane has already been missed for peanut but is still relevant conceptually: early introduction (LEAP) reduces allergy, and the same early-introduction principle applies to his younger siblings if any, with the NIAID addendum recommending peanut from around four to six months and test-then-feed for the severe-eczema or egg-allergic infant. [1][2]

The stepwise chronic lane treats each organ. For eczema: an emollient foundation, a proactive topical corticosteroid or calcineurin-inhibitor regimen with weekend proactive therapy for recurrent flares, treatment of Staphylococcus aureus colonisation and infection, and dupilumab for severe unresponsive disease. For asthma, which is currently poorly controlled: step up to a daily inhaled corticosteroid preventer with a single-inhaler maintenance-and-reliever regimen, written asthma action plan, trigger control, and a biologic such as omalizumab or mepolizumab if severe disease persists; optimising asthma control is itself part of his anaphylaxis safety. For rhinitis: an oral non-sedating antihistamine and an intranasal corticosteroid, the most effective single therapy, with sublingual immunotherapy for confirmed troublesome disease. [5]

The peanut allergy may well resolve. Population-based data show that roughly one in five children resolve peanut allergy by four years of age, so serial specific immunoglobulin E trends should be tracked and a supervised oral food challenge arranged when the trend suggests resolution, because the challenge is the only test that confirms resolution and lifts the restriction. The family should be told the trajectory is toward improvement with the right plan. [3]

Oral immunotherapy with an agent such as AR101 desensitises a majority of peanut-allergic children, but the PACE meta-analysis confirmed a substantial burden of reactions and adrenaline use during treatment, so it is a shared decision rather than a reflexive escalation. The decision turns on the family's quality of life, the child's and carers' capacity to adhere to a daily dosing and escalation regimen, and the trade-off between the safety of strict avoidance with an autoinjector and the desensitisation-but-reaction-burden of active treatment. The integrated answer is to optimise everything else first, then offer the immunotherapy conversation on its merits. [6]