The Relationship between the Home Environment, Eczema and Skin Infections in Young Children in New Zealand

Abstract

Background: New Zealand has a high prevalence of childhood eczema and serious skin infections. The home environment is believed to play an important role in determining the risk of both eczema and skin infections in children. While both eczema and skin infections are recognised to be prevalent interrelated health conditions for which there are ethnic and socioeconomic disparities, the contribution of the home environment to these conditions in New Zealand has not been well defined. Objectives: The objectives of this thesis are to (1) describe the prevalence of eczema and skin infection in children at age 9-months and 2-years; (2) determine whether the home environment increases the odds of having eczema in young children; and (3) determine whether the home environment is associated with increased odds of skin infection in young children with eczema. Methods: 6228 children who had completed the 2-year interview were selected from the Growing up in New Zealand study. The demographic characteristics of the cohort at birth are generalizable to the national birth cohort. The period prevalence of eczema and skin infection was calculated. Associations between the home environment and the presence of eczema and skin infections among children with eczema were calculated by using multiple variable logistic regression models. The focus of the risk factor analysis was based on parental report of current symptoms of eczema and of a skin infection at the 2-year interview and with reference to the time interval from 9-months and 2-years of age. Results: 34% of parents in the study reported that their child had eczema at the 9-month interview and 18% reported current symptoms of eczema at the 2-year interview. 26% of parents reported doctor diagnosis of eczema at both age 9-months and 2-years. 8% and 7% of children in the study had a parental report of a skin infection and a doctor diagnosis of a skin infection respectively at the 9-month interview. At the 2-year interview, the prevalence was 14% and 13% respectively. Among children with a parental report of eczema, 10% and 9% of those children had a parental report of skin infections and a doctor diagnosis of skin infections at the 9-month interview. These percentages were 21% and 21% respectively at the 2-year interview. Among home environmental factors, only household crowding was found to be independently associated with parental report of current symptoms of eczema between the ages of 9-months and 2-years (aORmedium vs. low= 1.96, 1.30 – 3.08, aORhigh vs. low= 2.02, 1.28 – 3.30). Postnatal maternal smoking was associated with increased odds of having symptoms of eczema, but only among the children of mothers who breastfed their child for more than 4 months (aOR= 1.74, 1.07 – 2.85). Among children living in their own home, the presence of mould or mildew in the walls or ceilings in the room where the child slept at night was associated with current symptoms of eczema (aOR= 1.43, 1.01 – 2.03). Only heavy condensation in the room where the child slept at night was independently associated with parental report of a skin infection between 9-months and 2-years of age among children with current symptoms of eczema. For children who lived in households where other family members had a serious skin infection within the past 3 months (aORhigh vs. medium-low= 3.32, 1.02 – 10.78), and for children in private rental accommodation (aORhigh vs. medium-low= 2.15, 1.15 – 4.02), household crowding was independently associated with skin infection among those with current symptoms of eczema. Conclusions: The home environment may have a small modifying effect on childhood eczema and skin infection among children with eczema. Household crowding and dampness-related exposures may be associated with the presence of eczema and skin infection among children with eczema.