Dietary advice for children with eczema and possible food allergy: A Delphi consensus study

Problem

Atopic dermatitis (“eczema”) commonly appears in the first two years of life and it can be difficult to determine whether eczema symptoms are related to delayed food allergy. The use of food allergy tests to guide dietary exclusions for eczema control in young children is controversial. We conducted a consensus exercise on how dietary history and skin prick tests (SPTs) for four common food allergens (cow’s milk, hen’s egg, wheat and soya) should be used to guide dietary advice in children under 2 years of age with mild, moderate or severe eczema.

Approach

Fourteen clinicians from general practice, paediatrics, paediatric dermatology, paediatric allergy and paediatric nutrition in UK and Ireland took part in an online Delphi study over 15 weeks in 2022. In three rounds, participants gave their anonymous opinions on relevant clinical symptoms, allergens, SPT thresholds and dietary advice according to dietary history and SPT results. Participants received individualised and group feedback from each round. The findings were discussed in a final online workshop, chaired by an independent academic outside the research team. Consensus was defined as agreement of 80% or above; items with agreement <80% were carried through to the next round, or for discussion at the final workshop. All participants were invited to comment on the minutes of the final workshop, including two survey respondents who had been unable to attend the workshop.

Findings

Aside from one dietitian being unable to take part in round two, participants engaged with all surveys. From an initial list of 14 symptoms, 12 were identified as relevant to immediate allergy and 7 for delayed allergy. Regarding allergens for SPT, consensus was reached for wheat and soya (to use commercial reagents) but not hen’s egg or cow’s milk. SPT wheal size for all study foods was determined negative at 0-1mm and sensitised at 5mm and above, but interpretation of wheals 2-4 mm in size varied. Agreement was reached at the final workshop on a flowchart of dietary advice to be given according to dietary history and SPT results. Dietary advice encompassed: food exclusion, oral food challenge, home dietary trial, and food inclusion.

Consequences

We obtained expert consensus on what dietary advice should be offered to parents and carers of children under two years of age with eczema when SPTs are employed to guide dietary decision making. The resulting flowchart may be useful in clinical practice and will underpin advice given to participants in the intervention arm of our Trial of food allergy (IgE) tests for Eczema Relief (TIGER) trial (NIHR133464, ISRCTN52892540).