Hard water linked to risk of itchy red rash in infants

Skin barrier impairment and dry skin are thought to be triggers of eczema in early life, partly through genetic predisposition. Environmental factors may also contribute to the breakdown of the skin barrier.

The study examined the link between water hardness and chlorine concentrations in household water, damage to the skin's natural barrier and eczema in infancy.

The researchers studied 1,300 three-month old infants from families across Britain and gathered data on levels of water hardness (calcium carbonate) and chlorine in their household water from local water suppliers.

The infants were checked for atopic childhood eczema and their skin's barrier function was assessed by measuring transepidermal water loss on the skin of an unaffected forearm. 

The findings, published in the Journal of Allergy and Clinical Immunology, showed that living in a hard water area was associated with an up to 87 percent increased risk of eczema at three months of age, independent of domestic water chlorine content. 

"Our study builds on growing evidence of a link between exposure to hard water and the risk of developing eczema in childhood,” said lead author Carsten Flohr from 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," Flohr said.