Eczema can leave children prone to developing food allergies in later life by allowing their immune systems to be primed incorrectly.
A new study has shown that eczema causes the barrier formed by the skin to breakdown, exposing the young immune system to allergens from foods like peanuts and cow’s milk.
The scientists, from Kings College London, found that children with eczema were six times more likely to be sensitive to six foods that commonly cause allergies.
The more severe the skin condition, which is caused by inflammation resulting in a rash and cracked skin, the more sensitive the children were found to be.
It is thought that by damaging the barrier created by the skin, eczema exposes the immune system beneath the skin to particles of food that it would not normally encounter.
This primes it to see these food particles as a threat and so cause inflammation when it encounters them in the future. In people with severe allergies this can result in swelling and even shock.
Around one in five children suffer from eczema and almost one in twelve children suffer from a food allergy.
Dr Carsten Flohr, a dermatologist who led the study at Kings College London and ST John’s Institute of Dermatology at St Thomas’ Hospital, London, said it appeared eczema plays a key role in the development of allergies by damaging the barrier created by the skin.
He said: “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 findings are published in the Journal of Investigative Dermatology.
Richard Gray - telegraph.co.uk