High domestic water calcium carbonate (hard water) levels might be associated with an increased risk of atopic dermatitis (AD) in infancy, according to a report published online in the Journal of Allergy and Clinical Immunology (Apr. 28, 2016).
The investigators recruited 1,303 three-month-old infants from families across the U.K. who were already participating in the Enquiring About Tolerance (EAT) study. They looked at the effect domestic hard water and chlorine concentrations had on the risk of these infants developing AD or skin barrier dysfunction.
At enrollment, infants were examined for AD and screened for filaggrin (FLG) skin barrier gene mutation status. The degree of transepidermal water loss was measured on unaffected forearm skin.
Findings indicate that living in a hard water area was associated with an up to 87% increased risk of eczema at three months of age, independent of domestic water chlorine content. The risk tended to be higher in children with mutations in the FLG skin barrier gene, although these latter results were not statistically significant.
“Our study builds on growing evidence of a link between exposure to hard water and the risk of developing eczema in childhood. It’s not yet clear whether calcium carbonate has a direct detrimental effect on the skin barrier, or whether other environmental factors directly related to water hardness, such as the water’s pH, may be responsible,” said Dr. Carsten Flohr, lead author of the Journal of Allergy and Clinical Immunology study, who was quoted in a press release.
Interactions between hardness and chlorine levels, other chemical water constituents and the skin’s microflora may also play a role, and warrants further research, commented Dr. Flohr, head of the Unit for Population-Based Dermatology Research at St John’s Institute of Dermatology at King’s College London.
“We are about to launch a feasibility trial to assess whether installing a water softener in the homes of high risk children around the time of birth may reduce the risk of eczema and whether reducing chlorine levels brings any additional benefits,” said Dr. Flohr.