Time to symptom improvement using elimination diets in non‐Ig E ‐mediated gastrointestinal food allergies

Background The prevalence of food allergy has increased in recent decades, and there is paucity of data on time to symptom improvement using elimination diets in non‐Immunoglobulin E (IgE)‐mediated food allergies. We therefore aimed to assess the time required to improvement of symptoms using a symptom questionnaire for children with non‐IgE‐mediated food allergies on an elimination diet. Methods A prospective observational study was performed on patients with non‐IgE‐mediated gastrointestinal food allergies on an elimination diet, who completed a questionnaire that includes nine evidence‐based food allergic symptoms before and after the exclusion diet. The questionnaire measured symptoms individually from 0 (no symptom) to 5 (most severe) and collectively from 0 to 45. Children were only enrolled in the study if collectively symptoms improved with the dietary elimination within 4 or 8 weeks. Results Data from 131 patients were analysed including 90 boys with a median age of 21 months [ IQR : 7 to 66]. Based on the symptom questionnaire, 129 patients (98.4%) improved after 4‐week elimination diet and only two patients improved after 8 weeks. A statistically significant difference before and after commencing the elimination diet was seen in all nine recorded symptoms (all p < 0.001), and in the median of overall score (p < 0.001). Conclusion This is the first study attempting to establish time to improve after commencing the diet elimination. Almost all children in this study improved within 4 weeks of following the elimination diet, under dietary supervision.