A study involving nearly 280,000 individuals of European ancestry investigated gene-environment interactions in eczema. The researchers found that a specific genetic variant near the IL7R gene was linked to an increased risk of eczema, but only in individuals not exposed to dogs during infancy. Exposure to dog allergens appeared to activate protective immune responses in genetically susceptible individuals. However, interactions with other environmental factors, such as cat ownership and tobacco smoke, were inconsistent. The study suggests that early-life exposures, particularly dog ownership, may modify genetic risk for eczema through skin immune mechanisms.

Source: Allergy