This finding was published by Olympia Tsilochristou and her colleagues from King’s College in London, UK, and from the US in May 2019.
Which bacterium was identified?
The bacterium is called Staphylococcus aureus (S. aureus). It is usually harmless and is found on the skin and in the mucous membranes of 25-30% of healthy people, where it goes completely unnoticed.
The name comes from the Greek staphylé meaning ‘grape’ and kókkos meaning ‘grain’ or ‘corn’. The Latin word aureus means ‘golden’. The name translates roughly as ‘golden grape ball’.
What did the researchers want to test?
S. aureus has already been linked for some time to the occurrence of eczema, allergic rhinitis, asthma and food allergies. We also know that severe eczema increases the risk of developing food allergies.
The researchers wanted to know more precisely how S. aureus, food allergies and the severity of eczema are related.
How did the researchers conduct the study?
They examined data that had already been collected in 2015 for the LEAP study, a very well-known allergy study. LEAP is the abbreviation of ‘Learning Early About Peanut Allergy’. The study investigated 640 children with severe eczema and/or a chicken egg allergy.
Now the research team has conducted a new analysis to determine whether children with S. aureus also have an allergic reaction to certain foods. They took a closer look at the data on the immune protein IgE. There is a specific IgE protein for every food, which makes it possible to determine what exactly is causing the allergic reaction. The researchers also looked at the severity of eczema in children with S. aureus.
What were the findings?
Children with severe eczema (also called atopic dermatitis) and/or an egg allergy who had evidence of S. aureus on their skin had higher levels of anti-peanut and anti-egg white IgE than children without S. aureus.
Furthermore, egg allergies in children with S. aureus often remained until the age of five or six years. This was unusual, since egg allergies usually disappear in most children before they reach this age. The researchers also discovered that children with S. aureus are more likely to develop a peanut allergy.
Why is this study important?
There is an association between S. aureus and food allergies in children with eczema. S. aureus should therefore be included as an additional risk factor for food allergies in children with eczema. It may be possible to prevent food allergies by treating S. aureus in infancy. Further studies must be conducted in order to determine whether this is an effective therapeutic approach, says Olympia Tsilochristou, the author of the study.
Tsilochristou O et al. Association of Staphylococcus aureus colonization with food allergy occurs independently of eczema severity. J Allergy Clin Immunol. 2019 May 29. pii: S0091-6749(19)30611-6. Epub ahead of print.
Du Toit G et al. Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy
Twitter-Account of London-based allergy specialist Olympia Tsilochristou
Presse Release from King’s College London