We plan to identify genetic markers across the genome for subtypes of childhood eczema across the course of disease. These phenotypes include "no eczema", early transient eczema", "late-onset eczema", "intermittent eczema" and "persistent eczema", which have been generated using information from 5 points in times throughout childhood. These time points include age 6 months to 1 year; 2-3 years; 4-5 years; 8-10 years and 14-18 years of age. This study will help us understand the genetic and environmental factors that may differ between different disease subtypes, and will help inform the definition of eczema and how it is treated.