Atopic dermatitis tied to increased tooth decay risk in children
Atopic dermatitis (AD) during infancy is associated with an increased risk of developing tooth decay by age three, according to results from the GUSTO* study.
The longitudinal study enrolled pregnant women during their first trimester (ie, gestational period of <14 weeks) in Singapore, who reported to questionnaire at 3, 6, and 12 months after giving birth on whether their infants had been diagnosed with AD by a physician. Skin prick tests (SPTs) were performed at 18 months and oral examinations were conducted at 24 and 36 months to detect early childhood caries (ECC). Development of wheal size of ≥3 mm was considered as a positive (+ve) response in SPT.
Based on the questionnaire and SPT results, 4.9 percent (35 of 709) of children with AD responded positively in SPT [AD-SPT(+ve)], 11.1 percent (79 of 709) with AD were tested negative in SPT [AD-SPT(-ve)], and 84 percent (595 of 709) did not develop AD (non-AD group). [J Allergy Clin Immunol 2017;doi:10.1016/j.jaci.2016.10.038]
The AD-SPT(+ve) group had a more than threefold increased risk of developing ECC at age 2 years (adjusted odds ratio [adjOR], 3.29; p=0.038) and 3 years (adjOR, 3.09; p=0.015) compared with the non-AD group.
However, ECC risk was not significantly different between children with AD-SPT(-ve) and those without AD at 2 and 3 years of age.
“Although not all cases of AD were associated with ECC, those with a positive SPT result were at a higher risk of ECC at both 2- and 3-year dental examinations,” said the researchers, who added that a positive SPT result minimizes the likelihood of nonallergic rashes being misclassified as AD.
Of the 397 children who were free of caries at 2 years, 35.8 percent developed new ECC lesions when they were subsequently re-examined at 3 years. Compared with those without AD, children with AD-SPT(+ve) also had a higher risk of increase in surface-level ECC between age 2 and 3 years (adjOR, 3.02; p=0.049).
All the multivariable analyses adjusted for potential confounders, such as sex, household income, ethnicity, maternal smoke exposure during pregnancy, maternal education level, and smoke exposure in the first year after giving birth.
According to the researchers, a possible mechanism behind the association between AD and ECC may be due to defects in structural gene, for instance, the distal-less homeobox (Dlx-3) gene known to regulate epidermal differentiation and enamel formation.
They also pointed out that due to limited resources, physician examination was not performed at the 3-monthly time points within the first year, and further studies with AD diagnosis based on physician report are needed to confirm their findings.