Trial of IGe tests for Eczema Relief (TIGER).
Funding:
National Institute for Health and Care Research (NIHR), Health Technology Assessment (HTA) Ref. NIHR133464.
What is the research question?
Does dietary advice based on routine food allergy tests improve disease control compared with usual care in children with eczema?
What is the problem?
Eczema is a common long-term condition, affecting 20% of children and while our understanding of the condition has improved, promising prevention strategies have disappointed. In the 2013 Global Burden of Disease Study, eczema was the skin disease with the greatest population-level disability. The impact can be seen in preschool children, with significant impact on the physical, emotional, and social functioning of the affected child and their family. In the UK, most children with eczema are managed through daily use of topical treatments. Though sticking to treatment can be difficult with many parents seeking a “cause” rather than controlling the disease.
Many parents are concerned about an undiagnosed food allergy as the cause for their child’s persistent eczema symptoms. Children with early onset and severe eczema are at increased risk of immediate food allergies. While alarming, this type of reaction is generally easy to recognise and can be managed with clear guidance to avoid the causal food. However, many parents are concerned with possible delayed reactions. This made more difficult as eczema can seem to be getting better but then relapses, making it harder to determine the cause. It is common for parents to restrict the diet of the affected child without discussion with a health professional. This is a potentially dangerous decision that can lead to malnutrition. Parents who do discuss the role of diet in eczema with their doctor often ask about allergy testing to guide dietary exclusions. In this situation, evidence to guide food allergy testing is weak, and opinions on its value are divided, leading to variation in clinical practice and confusion for parents.
Essentially, parents commonly seek food allergy tests or restrict diets, to find a cause for their child’s eczema, yet the value of test-guided dietary advice is uncertain.
What is the aim of the research?
To determine the clinical and cost effectiveness of test-guided dietary advice versus usual care, for the management of eczema.
How will this be achieved?
A previous trial suggested that infants with eczema who had a positive allergy test for egg benefitted from an egg-free diet, but a better-designed study is needed. We have shown it is feasible to do a trial in primary care to answer the question “Does dietary advice based on food allergy tests improve disease control in children with eczema?”
We will recruit 493 children less than 2 years old with eczema from 84 GP surgeries in three areas of England. They will be randomised to two groups: “usual care” and intervention, who will have skin prick tests for four foods that commonly cause allergy: milk, egg, wheat, and soya. Depending on what the tests show, parents will be advised to exclude or include one or more foods for 1 month. Children with unclear results will be observed eating the food at their local allergy clinic. Our main outcome is parent-reported eczema control. We will ask parents to complete questionnaires every month for one year. We will assess children’s skin at the beginning and end of the main outcome period (6 months). We will also measure children’s quality of life, dietary variety, and growth.
To assess value-for-money, we will collect health and care costs. It is also a unique opportunity to look for genetic risk factors by collecting spit samples. Making changes to children’s diets based on test results is complex, so we will do a “process evaluation” to assess how things work. This will involve observing the research in action and talking with some participants.
Who is leading the research?
Professor Matthew Ridd, Professor Primary Health Care, University of Bristol.
Further information:
For more information or to get involved in this project, please contact bnssg.research@nhs.net.
The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.