Atopic Dermatitis in Early Life: Evidence for at Least Three Phenotypes? Results from the GUSTO Study.

Background: Atopic dermatitis (AD) has been highlighted as a likely first step in the ‘atopic march', emphasizing the need to define predisposing factors. Methods: We evaluated AD risk factors and phenotypes in an Asian mother-offspring cohort. We defined three phenotypes of doctor-diagnosed AD based on the time of onset of the disease: early AD occurring within the first 6 months of life, AD occurring between 6 and 12 months and late-onset AD starting after the age of 12 months. Results: Maternal allergic history was associated with an increased risk of developing early-onset AD (adjusted odds ratio (aOR) 20.46, 95% confidence interval (CI) 2.73-153.15, p Conclusion: We found that early-onset AD was mainly associated with familial factors, while late-onset AD was associated with the consumption of antibiotics or probiotics. The findings support the concept that different phenotypes of AD exist in young children.