Food allergy concurrent with atopic dermatitis: Correlation with age of onset and severity

Background: Data on the frequency of food sensitivity (FS) and food allergy (FA) in patients with atopic dermatitis (AD) differ among studies. Objectives: The aim of this study was to determine the frequency of FS and FA in different AD phenotypes according to the age of onset and severity of AD. In addition, we aimed to investigate the risk of FA in these patients. Methods: Patients diagnosed with AD between 2022 and 2024 were included in the study. All patients with AD admitted during this period were analyzed for the coexistence of FA and FS. Results: The study included 257 children with AD. Of these patients, 147 of 257 were girls (57.2%). The median (interquartile range [IQR]) age of onset of AD was 6 months (2.5-30 months). By the age of AD onset, FS and FA were present in 60.3% and 32.5%, respectively, in patients with moderate-to-severe AD, with disease onset between ages 0 and 3 months. Among the patients with disease onset between ages 4 and 11 months, the corresponding rates in moderate-to-severe cases were 59.6% for FS and 17.4% for FA. FS was present in 39.3% of moderate-to-severe cases with AD onset age after 12 months, but none had FA. Being in the moderate-to-severe category for AD increased the risk of FA 14-16 times compared with the mild AD group. Conclusion: FS is significantly more prevalent than FA in patients with AD. In children in whom FS test results are positive, the diagnosis of AD-FA coexistence should not be made without performing an elimination diet and oral food challenge test. This approach will help prevent unnecessary food elimination.