Phthalates are widely used in our daily lives, including flooring, toys, food wrapping, plastic ware, emulsifying agent, lotion and shampoo. Several studies reported the association between the exposure to phthalates and allergic disorders. Also, some conflicting results reported whether atopic dermatitis is associated with overweight or obesity. We evaluated the association of phthalate exposure and overweight/obesity in atopic dermatitis (AD) of Korean children and adolescents.
The nationwide representative survey was conducted with 1820 children and adolescents aged 6 to 18 years in Korea. The information of atopic dermatitis was collected by the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Urine monobenzyl phthalate (MBzP), mono-n-butyl phthalate (MnBP), mono-2-ethyl-5-carboxypentyl phthalate (MECPP), mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) were measured. All phthalate metabolites were adjusted with urine creatinine. The subjects, who were overweight or obese, were defined that body mass index was between 85 and 95 percentile or over 95 percentile of age and gender, respectively.
The prevalence of AD diagnosis and current AD (diagnosed and presented symptoms during recent 12 months) was 29.4% and 16.4%, respectively. The proportion of subjects who were overweight and obese was 13.3% and 6.7%, respectively. We divided 4 groups according to the urinary phthalate levels (below or over average) and BMI (normal or overweight/obese). The subjects who were overweight or obese and exposured to higher urinary MnBP, MEOHP or MEHHP were the highest odds ratios compared to other groups in diagnosis of atopic dermatitis [OR(95% CI) 1.584(1.043-2.406) in MnBP; 1.632(1.066-2.498) in MEOHP; 1.584 (1.049-2.393) in MEHHP)]. The subjects who were overweight/obese and exposured to higher urinary MnBP or MEHHP were the highest odds ratios compared to other groups in current symptoms of atopic dermatitis [OR(95% CI) 2.091(1.294-3.378) in MnBP; 1.797(1.101-2.932) in MEHHP)].
Overweight or obesity and exposure to higher phthalate, especially to MnBP, MEOHP or MEHHP could be associated with an increased prevalence of diagnosis or current symptoms in atopic dermatitis.
This study was supported by the National Institute of Environmental Research (NIER).