Babies’ leaky skin may be factor in eczema and food allergies

Prof Alan Irvine, consultant paediatric dermatologist at Our Lady’s Children’s Hospital in Crumlin and associate professor of dermatology at Trinity College Dublin (TCD) is excited by new research findings published by researchers at TCD and National University of Ireland Cork this year.

“We looked at the skin barrier in babies and found that the top 25 per cent of babies who showed high water leakiness had a hugely increased risk of eczema,” explains Irvine.

While researchers acknowledged the importance of family history in the study, this finding is a strong marker for the future direction of research into the understanding of these skin conditions.

“We discovered almost 10 years ago that a mutation in the filaggrin gene is linked to eczema,” says Irvine. A deficiency in the filaggrin gene is also linked to asthma and food allergies, and these conditions often co-exist with eczema in childhood.

Early treatment

However, this new discovery will now push researchers towards investigating whether very early treatment of eczema in babies will be the way forward.

“This study shows that the die is cast early for skin conditions such as eczema. What we’d like to do next is to study this top 25 per cent of babies and see if immediate treatment can prevent the development of eczema,” he says.

Many children who suffer from eczema – the most common form of atopic dermatitis – show symptoms of the condition when they are four to six months old. The dry, flaky, red patches of skin usually appear before the age of two on the face, arms and in folds of the skin.

Standard treatment involves managing the condition with frequent use of good-quality moisturisers, the avoidance of soap products for washing and alternating the use of steroid-based creams with non-steroidal creams.

All these treatments work towards restoring the protective permeability barrier in the skin. Keeping your home well-ventilated and cool, and ensuring babies and young children wear cotton clothing, especially next to their skin, are other protective measures.

Research into defects in the skin’s permeability has been central to the understanding of how skin conditions and food allergies develop.

Other exciting research strands include looking at how skin permeability contributes to food allergies in children who also suffer from eczema.

Skin barrier defect

An international study headed by Allan Linneberg, associate professor at the research centre for preventive medicine at the Glostrup University Hospital in Denmark, suggests that children with this skin barrier defect are at an increased risk of getting food allergies because microscopic amounts of food (such as wheat flour) penetrate the skin.

He also suggests that the timing and amount of the food (for example, cows’ milk) introduced might affect the risk of development of the food allergy.

Interestingly, holding off on the introduction of almost all foods until babies are six months old is a caveat of breastfeeding experts to prevent the development of food allergies.

Linneberg’s study also suggests that if the body’s first introduction to a certain protein comes in large amounts through eating it, the immune system might not find it appropriate to start fighting it.

However, the immune system might respond if the protein is introduced in a small amount through the skin.

Prof Irvine adds that subtleties like this are quite difficult to explain to parents, yet they again point to the significance of skin permeability in food allergies and skin conditions.

“One-third of children with moderate to severe eczema will also have food allergies, and some studies are now showing that when children are given small amounts of the food, they are less likely to react and develop the allergy,” says Irvine.

The Learning Early About Peanut (Leap) allergy study carried out by the Immune Tolerance Network in Britain found that when children at high risk of developing a peanut allergy are given a peanut-containing snack, they are much less likely to subsequently develop the peanut allergy.

Randomised trial

This study, which was also published this year, is the first randomised trial to prevent food allergy in a large group of high-risk infants.

“For decades, allergists have been recommending that young infants avoid consuming allergenic foods such as peanut to prevent food allergies,” says Prof Gideon Lack of King’s College London, the lead investigator on the Leap study.

“Our findings suggest that this advice was incorrect and may have contributed to the rise in peanut and other food allergies.”

If anything, new research findings such as these encourage us all to keep an open mind about what the established scientific community holds firm on. Because, sometimes, a whole new assessment of the situation heralds new preventative approaches to conditions that have been well managed but never fully treatable.