The newly discovered link encourages early dental referral of children with atopic dermatitis (AD), which may help prevent tooth decay later in life
New findings indicate that babies with eczema were three times more likely to develop tooth decay at 2 and 3 years of age. The relationship between eczema, or atopic dermatitis (AD) and tooth decay is largely unknown, and this is the first time a link between the two diseases has been discovered. In a paper recently published in The Journal of Allergy and Clinical Immunology (JACI), the research team outlined how they found the link between eczema and tooth decay, and the need for timely intervention to ensure early detection and prevention of tooth decay in toddlers.
The research was led by the National University of Singapore (NUS) Faculty of Dentistry, which is part of the National University Health System (NUHS), and Singapore Institute for Clinical Sciences (SICS) of the Agency for Science, Technology and Research (A*STAR). The study was part of the Growing Up in Singapore Towards healthy Outcomes (GUSTO) programme, a nationwide birth cohort study involving collaborators from the NUS, NUHS, KK Women’s and Children’s Hospital (KKH), and SICS.
In the United States, tooth decay is the most common childhood disease, affecting five times as many children as asthma. In Singapore, a study published in 2009 led by the NUS Faculty of Dentistry revealed that 4 in 10 preschool children here had tooth decay, even though the water fluoridation rate is among the highest in the world. Eczema is one of the most common skin conditions worldwide and affects about one in five school-going children in Singapore4.
“Tooth decay is one of the most common diseases affecting young children but one which is highly preventable,” said Dr Stephen Hsu, the paper’s corresponding author, and Associate Professor at the NUS Faculty of Dentistry. “Our latest findings will give parents and caregivers of babies with eczema early warning of increased risk of developing tooth decay in toddlers. Regular dental check-ups can then be conducted to help minimise the incidence of tooth decay in these children.”
“To the best of our knowledge, our study is the first longitudinal study showing an association between eczema and tooth decay.” said Dr Evelyn Loo, co-first author and research fellow at SICS, “More knowledge about the condition will help medical professionals, parents, and caregivers provide better support for this group of children.”
The research team recruited pregnant women during their first trimester as part of the GUSTO study. After birth, the parents were then provided with an interviewer-administered questionnaire at 3, 6, and 12 months to identify children who had been diagnosed with eczema. In addition, the children also underwent skin prick testing (SPTs) to determine if they are sensitised to common allergens.
Based on the responses to both the questionnaire and SPTs, children in the GUSTO study were categorised into three groups, AD-SPT(+ve), AD-SPT(-ve), and non-AD groups. Tooth decay was detected using modified International Caries Detection and Assessment System (ICDAS) criteria at 2 and 3-year visits.
Higher risk of tooth decay was demonstrated in the AD-SPT(+ve) group at both 2 and 3 years of age. Compared to the non-AD group, the AD-SPT(+ve) group was 3.29 times and 3.09 times more likely to experience tooth decay, at the 2-year and 3-year marks respectively, indicating a positive correlation between AD and tooth decay.
A possible mechanism behind the link between the two diseases could be structural defects during tissue development. However, no difference in tooth decay risk was observed between the AD-SPT(-ve) group and non-AD groups.
The team is currently conducting genetic analysis to confirm the aforementioned mechanism and exploring the link between tooth decay and other childhood diseases potentially affected by ectodermal defects.
Set up in 2009, GUSTO is a detailed long-term study of pregnant Singaporean mothers and their offspring. The study aims to better understand just how profoundly genetic and environmental factors affect neurodevelopment, as well as the onset of metabolic diseases such as diabetes and obesity in later years. Since its inception, the study has recruited 1,247 Singaporean families, and deeply phenotyped them through pregnancy and early childhood.
GUSTO aims to understand how conditions during pregnancy and early childhood may affect the mothers’ and children’s health, growth and development, as well as metabolic, neurodevelopmental and other conditions – all of which are of major public health and economic importance in Asia and around the globe. The research spans four themes, with studies designed to develop public health policies; clinically-valuable, testable interventions; reduce the burden of childhood obesity and non-communicable diseases, e.g. diabetes; and improve neurodevelopmental outcomes in children.