Sharing of the microbiome through skin contact between children with atopic dermatitis (AD) and their caregivers may contribute to disease recurrence.
This finding comes from a paper published in The Journal of Allergy and Clinical Immunology.
The authors of the paper note that AD flares often occur due to a reduction in microbial diversity and a predominance of S. aureus on the skin of individuals with AD. While treatment for AD may reduce S. aureus colonization of the patient, the investigators note that the patient’s family may represent a reservoir of S. aureus that could lead to recolonization.
To understand how microbiomes are shared between children with AD and their caregivers, researchers recruited 30 children with moderate to severe AD, between the ages of 0 to 10 years, and one healthy primary caregiver for each child. Each primary caregiver had to be someone living in the same household as the child and spent at least eight hours a day with the child for the past six months.
Investigators collected skin samples from non-lesional skin at common flare sites, such as the forearms, cheeks, and the inside elbow of children and their primary caregivers. They also collected samples from lesional skin in the AD patients.
They found distinctive microbial signatures in the healthy caregivers which were similar to the non-lesional skin of AD children, despite the absence of any skin disease in the caregivers.
More abundant S. aureus compared to commensal Staphylococcus hominis was found to be a sensitive and specific marker for affiliation to an AD household, regardless of whether the adults or children were otherwise healthy. The researchers write that report this means that the ongoing skin microbial sharing between children with AD and their caregivers could increase the tendency for the recolonization of S. aureus strains in the child, which would exacerbate their skin inflammation.
The authors conclude that the sharing of skin microbes between children with AD and their close contacts is a significant factor contributing to treatment failure—when treatment ends patient skin is often quickly recolonized from contact with family. Therefore, including close household contacts in treatment may be needed to break this chain of transmission.
In a press release, lead author Dr. Elizabeth Tham from the Department of Paediatrics at the Yong Loo Lin School of Medicine, National University of Singapore said: “Our research showed that management of AD is more than treating symptoms of disease flares, which is only a temporary solution. The transference of skin microbiota between individuals in close contact is understudied in the field of AD. This sheds light on the possibility that future therapeutic approaches in AD may require extension to close contacts to disrupt the infectious chain of transmission.”
Dr. Chia Minghao, Senior Research Fellow at A*STAR’s Genome Institute of Singapore and co-lead of this study said: “Our research is a promising step in discovering how to better manage skin conditions such as AD more efficiently, and to better understand how skin microbes contribute to disease. We are optimistic that similar research could bring us one step closer to eradicating pathogenic microbes that cause painful skin inflammation, and this would bring much-needed relief to those suffering from various skin conditions, other than AD.”