Levels of immunoglobulin E specific to the major food allergen and chemokine (C‐C motif) ligand (CCL)17/thymus and activation regulated chemokine and CCL22/macrophage‐derived chemokine in infantile atopic dermatitis on Ishigaki Island

Atopic dermatitis (AD) is a multifactorial T‐helper (Th)2‐mediated skin disease frequently associated with elevated serum immunoglobulin (Ig)E and food allergy is also a Th2‐ and IgE‐mediated adverse immunological reaction. Our previous study indicated the relation of egg allergy history and disease severity of AD. Thus, the purpose of the study was to investigate the levels of IgE specific to major food allergens (egg, milk, wheat) and Th2 chemokines (chemokine C‐C motif] ligand CCL]17/thymus and activation regulated chemokine TARC] and CCL22/macrophage‐derived chemokine MDC]) and the relationship between them. A total of 743 nursery school children were enrolled. Dermatologist‐based physical examination and a questionnaire survey were also conducted. Significantly increased levels of disease severity markers (CCL17/TARC and CCL22/MDC) were confirmed in children with AD. The levels of CCL22/MDC in all of the children were markedly high compared with those reported in adults. IgE specific to egg white, ovomucoid, wheat and mite antigen were significantly higher in the AD group than in the non‐AD group. Among them, IgE specific to egg allergens were well associated with disease severity markers, and IgE specific to ovomucoid seemed particularly well correlated with the presence of egg allergy history. In conclusion, the markedly high level of CCL22/MDC in children as compared with those reported in adults may partly explain the AD‐prone nature of children and their spontaneous remission afterwards. Mild but significant correlation of IgE specific to egg allergens and Th2 chemokines may explain correlation of disease severity and comorbidity of egg allergy in our previous study.