Navigating Atopic Dermatitis: Insights on Food Allergy Testing in Children

Atopic dermatitis (AD) affects up to 20% of children globally. Most cases are mild to moderate and are treated with emollients and topical corticosteroids (TCS). Concerns about these treatments lead caregivers to consider alternative options, such as food allergy (FA) testing. A recent study explored the link between AD and FA, current FA testing practices, and a Delphi consensus among UK clinicians.

Association Between AD and FA

Research shows a strong link between AD and food sensitization. Up to 50% of children with AD are sensitized to at least one food. In infants aged 0 to 2 years, clinical food allergies can occur in about 39.2%, especially in those with early-onset or severe AD. This overlap often prompts parents to restrict certain foods without professional input, risking a loss of tolerance to allergens. The authors stressed careful dietary choices to avoid complications.

Current Challenges in FA Testing

FA testing for children with AD is often inconsistent. Tests are commonly used when there are signs of immediate (IgE-mediated) or delayed (non-IgE) food allergies, particularly in severe cases. However, interpreting test results is challenging. Positive results from skin prick tests (SPT) or specific IgE tests do not always confirm clinical food allergies. There is no universal guideline for advising parents on test results. Testing should confirm or refute diagnoses based on a detailed history. Inappropriate testing can hinder effective AD treatment.

Study Overview

To clarify these issues, a Delphi consensus exercise was conducted with allergists, dermatologists, dietitians, general practitioners, and pediatricians. The aim was to create dietary advice guidelines for caregivers of children under 2 years with AD, focusing on common allergens like cow’s milk, hen’s egg, wheat, and soy. The study included three survey rounds and a final workshop with high participation.

Key Findings

The panel reached important conclusions on SPT results. They defined results as follows: a wheal size of 0 to 1 mm is negative, and sizes of 5 mm or larger indicate sensitization. Results between 2 to 4 mm were considered inconclusive. A flowchart was developed to standardize diagnostic pathways based on SPT results and symptoms. The panel agreed on using commercial extracts for wheat and soy SPTs but could not reach a consensus on the best materials for cow’s milk and hen’s egg.

Implications for Practice

This study provides practical guidance for clinicians managing children with AD and suspected food allergies. However, it highlights that routine FA testing has limitations. Clinicians should avoid over-reliance on these tests, as they can distract from essential AD management, which primarily involves consistent use of topical therapies.

The findings contribute to the ongoing discussion about the role of FA testing in AD management. As the Trial of Food Allergy IgE Tests for Eczema Relief (TIGER) progresses, more evidence will inform clinical practices. In the meantime, healthcare providers must balance parental concerns with evidence-based practices to prevent unnecessary food restrictions while optimizing AD control.