BABIES with eczema are more prone to developing food allergies - suggesting that treating the skin condition could help prevent problems occurring, Scottish research suggests.
The study found that the breakdown in the skin barrier and inflammation in the skin that happens in patients with eczema could play a role in triggering food sensitivity in infants.
In some cases, this sensitivity to certain products can lead to a more serious clinical allergy developing.
The research, carried out by Dundee University and Kings’s College London, analysed data from more than 600 three-month-old babies taking part in the Enquiring About Tolerance (EAT) study. All the babies were exclusively breast-fed from birth.
The infants were examined for signs of eczema, their skin tested for how much water it was able to retain and their genes screened for any mutations linked to eczema.
The researchers, writing in the Journal of Investigative Dermatology, also carried out a skin prick test to see if the babies were sensitive to the six most common allergenic foods.
Eggs most common
Overall the study found that infants with an impaired skin barrier, especially if they also had eczema, were over six times more likely than healthy infants to be sensitised to a variety of foods.
They found that egg white was the most common allergen in the babies studied, followed by cow’s milk and peanuts.
The researchers found that the more severe a child’s eczema was, the stronger the link to a higher risk of food sensitivity, regardless of any genetic factors which may also be present.
As the babies involved in the study had only had breast milk and not ingested any solid foods, the researchers said that the findings suggested that active immune cells in the skin - rather than the gut - may play an important role in food sensitisation.
They said that they believed the breakdown in the skin barrier in patients with eczema left active immune cells found in the skin exposed to allergens in the environment - in this case food proteins. This then triggered an allergic immune response.
The researchers said this opened up the possibility of finding ways to repair the skin to help reduce the risk of children going on to develop more serious allergies.
‘Flips it on its head’
Dr Carsten Flohr, clinician scientist and senior lecturer at King’s College, said: “This is a very exciting study, providing further evidence that an impaired skin barrier and eczema could play a key role in triggering food sensitivity in babies, which could ultimately lead to the development of food allergies.
“This work takes what we thought we knew about eczema and food allergy and flips it on its head – we thought that food allergies are triggered from the inside out, but our work shows that in some children it could be from the outside in, via the skin.
“The skin barrier plays a crucial role in protecting us from allergens in our environment, and we can see here that when that barrier is compromised, especially in eczema, it seems to leave the skin’s immune cells exposed to these allergens.
“It opens up the possibility that if we can repair the skin barrier and prevent eczema effectively then we might also be able to reduce the risk of food allergies.”
The researchers pointed out that food sensitivity did not always lead to a food allergy, which can cause much more serious reactions.
It is estimated that around one in 12 children in the UK have a food allergy and one in five suffer from eczema.
Both conditions can have a significant impact on patients and their families, often requiring treatment and in severe cases hospitalisation.