Common skin bacterium raises risk of food allergy in kids with severe eczema

Researchers at King's College London have found that young kids with serious eczema infected with Staphylococcus aureus (SA) bacterium are at an increased risk of developing a food allergy.

Staphylococcus aureus (SA) is a bacterium that can be found in the nose and the skin of healthy individuals. However, SA is more common in patients of eczema, especially severe eczema.

When someone has an allergy, their immune system mistakes a harmless substance (such as eggs or peanuts) as an intruder and overreacts in response. Their body produces an antibody known as Immunoglobin E (IgE).

When IgE encounters the intruder on the skin or within the body it releases chemicals, such as histamine that cause the allergic reaction.

The team of scientists found that young children with severe eczema who are infected with SA produce more IgE against peanut, egg and milk indicating they have a food allergy to each of these.

These children were also more likely to have their egg allergy persist at the age of five or six years in comparison to children that did not have SA present.

"This is significant as most children with egg allergy usually outgrow this at an earlier age," said, Dr Olympia Tsilochristou, lead author of the study.

"We do not know yet the exact mechanisms that lead from eczema to food allergy, however, our results suggest that the bacteria Staphylococcus aureus could be an important factor contributing to this outcome."

Scientists also found that children with SA on their skin and/or nose were more likely to develop peanut allergy despite them being fed with peanut from early ages as part of the LEAP study protocol.

"These findings indicate that SA may have reduced the chance of young infants gaining tolerance to peanut, even if peanut was eaten in early childhood," said Du Toit, Study's co-author.