New research suggests that skin bacteria may be anti-inflammatory, or protective against eczema

New research published online this month in the Journal of Allergy and Clinical Immunology indicates that the presence of certain harmless bacteria on the skin at 2 months of age is associated with a lower risk of atopic dermatitis at 1 year. 

Eczema, also known as atopic dermatitis (AD) is the most common skin disease of children in developed societies. It is associated with intense itch and loss of sleep in early life and with other conditions, such as food allergy and asthma in later life.

The early origins of AD are still not fully understood. We do know that AD involves a complex interplay between the skin barrier, certain abnormal immune system responses, and what is known as the microbiome (the collective name for the community of organisms that live on all of our skin).

Staphylococcus Aureus is a type of bacteria which is frequently found on the skin and in the nose, in healthy people. However, AD has a close relationship with Staphylococcus Aureus, such that its presence on the skin (colonization) is known to drive flares or exacerbations of AD.

It was, however, not known which came first, colonization by staphylococcus, or AD followed by staphylococcal colonization?

In collaborative work funded by the National Children’s Research Centre, researchers in Trinity College Dublin, University College Cork, Dundee and the National Institutes of Health, followed a group of patients (the Cork BASELINE Cohort) very carefully over a 1 year period, and regularly took skin swabs to sample their skin microbiome.

Researchers were able to show that Staphylococcus colonization did not occur before development of AD and, surprisingly, several non-aureus species of Staphylococcus actually appeared to be protective against developing AD at 1 year of age.

This is an important new finding in the complex relationship between the microbiome and skin inflammation, suggesting that some organisms that reside on our skin may be anti-inflammatory, or protective against developing AD.


Kennedy EA, Connolly J, Hourihane JOB, Fallon PG, McLean WHI, Murray D, Jo JH, Segre JA, Kong HH, Irvine AD. Skin microbiome prior to development of atopic dermatitis: early colonization with commensal staphylococci at 2 months is associated with a lower risk of atopic dermatitis at 1 year. Journal of Allergy and Clinical Immunology 2016

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