D1.294 - Does food allergy test-guided dietary advice improve eczema control in children? Protocol for Trial of food allergy IgE tests for Eczema Relief (TIGER) study

Parents/carers are often concerned that a food allergy is the underlying cause of their child’s atopic dermatitis/eczema and request allergy testing. Access to tests can be limited and opinion on the use of allergy tests in this context varies. A previous study suggested that the eczema of infants who are sensitised to egg may improve with an egg-free diet, but a larger, better-designed study is needed. The aim of this study is to determine the clinical and cost effectiveness of test-guided dietary advice for four common allergens versus standard care, for eczema management.

Pragmatic, multi-centre, parallel group, individually randomised controlled trial (ISRCTN52892540), with nested economic and process evaluations. 493 children (3 months to <2 years old) with at least mild eczema are being recruited (May 2023-August 2025) from GP surgeries in England and randomised 1:1 to comparator or intervention groups.

All participants receive our leaflet on “Good eczema care”. Those in the intervention group also undergo skin prick tests to milk, wheat, egg and soy, and are advised to eliminate any foods to which they are sensitised for 4 weeks.

The primary outcome is eczema control, measured by the parent completed RECAP, collected four-weekly over 24 weeks. Secondary outcomes include: eczema symptoms; quality of life; adverse events; breastfeeding status and diet; growth; parental anxiety. The primary analysis is a multilevel mixed model framework with observations over time nested within participants.

A cost-utility analysis will compare quality-adjusted life years (QALYs) for the child and main carer to costs incurred by the National Health Service (NHS). Additionally, costs from NHS and non-NHS perspectives will be related to a range of outcomes in a cost-consequences approach.

A nested process evaluation will assess intervention fidelity, clarify causal mechanisms, and identify contextual factors associated with variation in outcomes.

To date (January 2025) 317 participants have been randomised from 103 practices: 80% are white with mean age of 15 months and around one-third of intervention participants are sensitised to one or more study foods. 18 clinicians and 21 parents have been interviewed.

This study will fill an evidence gap of importance to patients and carers, and reduce variation in practice and associated harms.