Association between skin barrier development and early-onset atopic dermatitis: a longitudinal birth cohort study

BACKGROUND: A diagnosis of atopic dermatitis (AD) is common during infancy; however, it is unclear whether differential skin barrier development defines this period and signals disease onset in predisposed individuals. OBJECTIVE: A longitudinal observational cohort study (NCT03143504) assessed the feasibility of remote skin testing from birth to monitor skin barrier maturation and model association with an AD diagnosis by 12-months of age. METHODS: Biophysical testing and infrared spectroscopy were conducted at the maternity ward and family home. Tape stripping collected samples for desquamatory protease and Natural Moisturising factor (NMF) analysis. The four common European Filaggrin (FLG) risk alleles were screened. RESULTS: A total of 128 infants completed the study with 20% developing mild disease. Significant changes in permeability barrier function, desquamatory protease activity and molecular composition assessed spectroscopically were observed longitudinally, but only subtle evidence of differential skin barrier development was noted between infant subgroups. Common FLG risk alleles were strongly associated with early onset disease and conferred a significant reduction in NMF and water content by four weeks of age. Accounting for a family history of atopy, these parameters alongside a greater lipid/protein ratio and reduced chymotrypsin-like activity at birth were associated with AD. Measured in ambient conditions, transepidermal water loss did not signal disease risk at any stage. CONCLUSION: Skin barrier dysfunction lacked an acquired modality but was considered proportional to cohort severity and suggests that a portfolio of tests used in a community setting, has the potential to improve current AD risk evaluations from birth.