Early identification of those at risk opens up the possibility of actually preventing eczema — through an act as simple as applying moisturiser during the first year of life — although those involved in the research said further studies are needed to back this up.
The Baseline Allergy study group, led by consultant paediatrician Jonathan Hourihane and research fellow Maeve Kelleher, both of University College Cork, and Alan Irvine of Trinity College Dublin measured water evaporation in the skin of 1,903 newborn babies in Cork University Hospital, and followed them up until 12 months of age.
Prof Hourihane described the test as “painless” and “non-invasive”, with a small probe placed on the child’s arm. “It’s like putting a hollow toothbrush on the arm and the head measures the level of water evaporation in an enclosed area,” he said.
This “simple bedside test” was carried out on the babies on day two following birth and at two months.
It could predict the development of eczema at 12 months — if water evaporation levels were high, the child was more likely to develop eczema.
Another factor in developing eczema, a chronic inflammatory skin disease, was whether a child’s parents also had allergies, as well as whether the child carried a mutation in the FLG gene, which governs the amount of filaggrin (a protein). A low level of this gene was the hallmark of eczema, Prof Hourihane said.
A filaggrin deficiency causes defects in skin barrier function, making eczema more severe and skin infections and allergies more common.
Approximately 10% of people carry a mutation in the FLG gene.
Prof Hourihane said if both parents suffer from allergies, a child had a “25%-40% chance of developing eczema in their first year”. If the child had a filaggrin deficiency, the chance iss 40%-50%. However, if all three elements are involved — parental allergies, filaggrin deficiency, and high water evaporation levels — then the child was seven times more likely to have eczema at 12 months, despite having no visible skin barrier defect or eczema at the time of measurement before they left the maternity hospital.
Prof Hourihane said that the study, published today in the Journal of Allergy and Clinical Immunology, was “the largest set of neonatal skin barrier assessments ever performed, just after birth”.
He said their findings offered hope that an intervention in the first 12 months of life could prevent eczema developing “in these highest-risk children targeted for a simple intervention with moisturisers to protect their skin barrier”.
He said it was “also fascinating” to find that low water evaporation levels after birth appeared to be protective for eczema at 12 months. He said this indicated there might be a “double-edged” benefit to using their test more routinely.
He said prevention of eczema may also prevent the development of asthma and food allergy, which are strongly associated with eczema, because the allergens get through the broken skin and cause the development of allergies.