Paediatric Food Allergy: From Oral Immunotherapy to Biologic Breakthroughs

The Growing Challenge of Paediatric Food Allergy

Food allergy affects approximately 8% of children worldwide, with prevalence continuing to rise across developed nations. In Hong Kong, the incidence of paediatric food allergy has doubled over the past two decades, placing an enormous burden on families and healthcare systems. For children with severe IgE-mediated allergies to peanuts, tree nuts, milk, or eggs, even trace exposure can trigger life-threatening anaphylaxis — a reality that profoundly impacts quality of life for both patients and their families.

Traditionally, the standard of care has been strict allergen avoidance combined with emergency adrenaline auto-injectors. However, this approach carries significant limitations: accidental exposures remain common, occurring in up to 40% of allergic children over a five-year period, and the psychological burden of constant vigilance can be debilitating. The past decade has witnessed a paradigm shift in food allergy management, moving from passive avoidance to active treatment strategies that aim to desensitise the immune system.

Oral Immunotherapy: A New Standard of Care

Oral immunotherapy (OIT) involves the gradual introduction of increasing doses of the offending allergen under strict medical supervision. The goal is to raise the threshold at which an allergic reaction occurs, thereby providing a safety net against accidental exposures. The landmark PALISADE trial demonstrated that peanut OIT (Palforzia) enabled 67% of treated children aged 4–17 to tolerate at least 600 mg of peanut protein — equivalent to approximately two peanuts — compared to only 4% in the placebo group.

In clinical practice, OIT protocols typically involve three phases: an initial dose escalation day conducted in hospital, a gradual up-dosing phase over several months with fortnightly dose increases, and a long-term maintenance phase. At our centre, we have successfully treated over 200 children with peanut, milk, and egg allergies using standardised OIT protocols. Key success factors include careful patient selection, robust safety monitoring, and comprehensive family education.

However, OIT is not without challenges. Approximately 10–15% of patients experience significant gastrointestinal side effects, and up to 5% may develop eosinophilic oesophagitis. Allergic reactions during dose escalation, while usually mild, require careful management. These limitations have driven research into adjunctive therapies that can improve both the safety and efficacy of immunotherapy.

Omalizumab: The First FDA-Approved Biologic for Food Allergy

In February 2024, the US FDA approved omalizumab (Xolair) for the reduction of allergic reactions in patients aged one year and older with IgE-mediated food allergies. This landmark approval was based on the OUtMATCH trial, which demonstrated that after 16–20 weeks of omalizumab treatment, 67% of peanut-allergic participants could tolerate at least 600 mg of peanut protein, compared to only 7% receiving placebo.

Omalizumab works by binding free IgE antibodies in the bloodstream, effectively reducing the amount of IgE available to trigger allergic reactions. What makes this therapy particularly valuable is its ability to provide protection against multiple food allergens simultaneously — a significant advantage for the estimated 30% of food-allergic children who react to more than one food. The OUtMATCH trial showed concurrent protection against cashew (42% vs 3%), milk (66% vs 10%), and egg (68% vs 0%) allergens.

A March 2025 study from Johns Hopkins Medicine further demonstrated that omalizumab may offer comparable or superior protection to OIT with fewer side effects, particularly for patients with multiple food allergies. This positions omalizumab as both a standalone treatment and a powerful adjunct to OIT, potentially enabling faster and safer desensitisation protocols.

Omalizumab-Facilitated OIT: Combining the Best of Both Approaches

Perhaps the most exciting development is the combination of omalizumab pre-treatment with subsequent OIT. A 2025 systematic review and meta-analysis published in Pharmaceuticals analysed data from multiple clinical trials and found that omalizumab-facilitated OIT achieved significantly higher desensitisation rates compared to OIT alone, while substantially reducing the incidence of adverse reactions during the up-dosing phase.

The protocol typically involves 8–16 weeks of omalizumab pre-treatment to lower baseline IgE levels, followed by accelerated OIT dose escalation. This approach allows patients to reach maintenance doses in weeks rather than months, with a markedly improved safety profile. For children with extremely high IgE levels or a history of severe anaphylaxis — patients who would traditionally be considered too high-risk for conventional OIT — this combination therapy opens a previously closed door.

Dupilumab: The Next Frontier

Dupilumab, an IL-4/IL-13 receptor antagonist already approved for atopic dermatitis and asthma, is emerging as another promising biologic for food allergy. A groundbreaking phase 2 trial (NCT03679676) investigated the sequential use of omalizumab followed by dupilumab to facilitate multi-allergen OIT. The results, published in the Journal of Allergy and Clinical Immunology in 2025, showed that adding dupilumab enhanced desensitisation outcomes and significantly reduced gastrointestinal symptoms — the most common reason for OIT discontinuation.

Dupilumab's mechanism of action differs from omalizumab: rather than binding free IgE, it blocks the signalling pathways that drive type 2 inflammation and IgE production at their source. Over 52 weeks of treatment, dupilumab has been shown to reduce total IgE levels by approximately 70%, suggesting it may offer more durable immune modulation. Clinical trials investigating dupilumab as a standalone treatment for food allergy are currently underway.

Hong Kong's Advantage in Paediatric Allergy Care

Hong Kong offers several distinct advantages for families seeking advanced paediatric allergy treatment. Our allergists are trained in both Western and Asia-Pacific protocols, with extensive experience managing the specific allergen profiles common in the region — including shellfish, fish, and wheat allergies that are less prevalent in Western populations. The city's world-class hospital infrastructure enables safe administration of immunotherapy with immediate access to intensive care facilities if needed.

For GCC families, Hong Kong provides a culturally sensitive, Muslim-friendly environment with halal food readily available throughout the city. The visa-free entry policy for GCC nationals eliminates administrative barriers, and the proximity of specialist clinics to international hotels makes extended treatment courses logistically manageable. Our multilingual medical teams include Arabic-speaking coordinators who facilitate seamless communication throughout the treatment journey.

Looking Ahead: Precision Medicine in Paediatric Allergy

The future of paediatric food allergy management lies in precision medicine — using biomarkers such as specific IgE levels, basophil activation tests, and component-resolved diagnostics to tailor treatment strategies to individual patients. Emerging research suggests that certain IgE epitope profiles may predict which children will respond best to OIT versus biologic therapy, enabling truly personalised treatment plans.

As we enter this new era of active food allergy treatment, the message to families is one of cautious optimism. While a definitive cure remains elusive, the combination of oral immunotherapy and biologic agents is transforming food allergy from an untreatable condition requiring lifelong avoidance into a manageable disease with effective therapeutic options. At our centre, we are committed to offering these cutting-edge treatments within a safe, evidence-based framework.