Study shows demographic and geographic variability in prevalence, with higher rates among African Americans, city dwellers, and on the East Coast.
Study results published in the January 2011 issue of the Journal of Investigative Dermatology show that roughly one in 10 US children has received a diagnosis of eczema/atopic dermatitis in the past 12 months.
Describing atopic dermatitis (AD) as “a global public health concern considering its increasing prevalence and mounting financial costs to health systems,” the authors of “Eczema Prevalence in the United States: Data from the 2003 National Survey of Children's Health” used data from the National Survey of Children's Health (NSCH) to examine “the geographical distribution of [AD] and explored whether certain risk factors and associations previously reported in Europe and Asia were also present in the US population.”
According to the authors, analysis of the data revealed that 10.7% of US children under the age of 18 have eczema, with prevalence ranging “from 8.7% to 18.1% between states and districts.” The highest state prevalence values “were reported in many East Coast states, as well as in Utah, Idaho, and Nevada.” The lowest state prevalence values “were in the middle and southwestern parts of the country.”
The study also found that 30.7% of children with eczema also reported concurrent hay fever; 22.8% of children with a diagnosis of eczema reported concurrent asthma. Significant determinants of eczema prevalence included younger age, households reporting education levels greater than high school, and city/urban living. Black race was also significantly associated with a higher prevalence of eczema compared with White race. Other factors associated with higher prevalence of eczema included insurance status (children with health insurance had greater eczema prevalence than did those without), family structure (only children and children of single mothers had a higher prevalence), and child care (children who received child care outside of the home had a high prevalence).
Discussing these results, the authors wrote that “Our large population-based study found the prevalence of AD in the United States to be ~10.7% with a significant variation between states and districts. Urban living and being of Black race were significantly associated with a higher prevalence of eczema after controlling for possible confounders. A general geographic trend toward higher disease prevalence in the East Coast states was also found.” They reported that these results “confirmed known demographic AD associations previously observed only in European populations, including the association of AD with higher education levels, higher household incomes, and smaller family sizes.” Associations not observed in this study included “a lack of association with smoking in the household, breast feeding, birth order, gender, or body mass index.”
Although these data revealed “significant geographic variability in disease prevalence within the United States with a higher prevalence in the East Coast states,” the authors were unsure of the cause of this variability, writing that it is likely “multifactorial.” They posit that “environmental factors, such as exposure to environmental pollution,” may account for the higher prevalence of AD among urban/city children. They also noted that a significant limitation of this study was that they “could not be certain whether geographic differences in disease prevalence reflected differences in access to medical care or dermatological specialty care.”