In the JournalsPerspective

S. aureus puts kids with severe eczema at higher risk for food allergy

Numerous studies have implicated Staphylococcus aureus in the development of eczema.

Now, in a secondary analysis of the Learning About Peanut Allergy, or LEAP, study, researchers have found that children with severe eczema who were colonized with the bacteria were significantly more likely to have a specific food allergy.

In LEAP, 640 children aged 4 to 11 months with severe eczema, egg allergy, or both were randomly assigned to consume or avoid peanuts until 60 months of age. The study found that the early introduction of peanuts significantly reduced the frequency of the development of peanut allergy. During the study, researchers documented children’s eczema severity and tested for S. aureus colonization at four different time points.

“This design provides a unique opportunity for the detailed investigation of the relationship between S. aureus and food allergy,” the researchers wrote.

In a secondary analysis of LEAP and a 12-month extension of that study, called LEAP-On, researchers investigated the association between S. aureus colonization and specific immunoglobulin E production to common food allergens in early childhood — such as milk, eggs or peanuts — independent of eczema severity. They also sought to determine the association of S. aureus colonization with eczema severity and persistence.

They found that although S. aureus colonization was associated with eczema throughout the study period, children who were colonized at ages 12 and 60 months demonstrated eczema deterioration.

Colonization with the bacteria at any time during the study was linked to increased hen’s egg white and peanut specific IgE levels. Furthermore, children colonized with S. aureus experienced persistent egg and peanut allergy at ages 60 and 72 months. These associations persisted regardless of eczema severity.

“This is significant because most children with egg allergy usually outgrow this at an earlier age,” study author Olympia Tsilochristou, MD, a clinical research fellow at King’s College London, said in a press release.

The researchers wrote that the relationship between eczema, S. aureus colonization and food allergy could be important in providing food allergy interventions.

“We do not know yet the exact mechanisms that lead from eczema to food allergy,” Tsilochristou said. “However, our results suggest that the bacteria S. aureus could be an important factor contributing to this outcome.” – by Katherine Bortz

Disclosures: Tsilochristou reports receiving grants from the Clemens von Pirquet Foundation in Geneva, Switzerland, during the conduct of the study. Please see the study for all other authors’ relevant financial disclosures.

Reference:

Du Toit G, et al. N Eng J Med. 2015;doi:10.1056/NEJMoa1414850.

Tsilochristou O, et al. J Allergy Clin Immunol. 2019;doi:10.1016/j.jaci.2019.04.025.

Numerous studies have implicated Staphylococcus aureus in the development of eczema.

Now, in a secondary analysis of the Learning About Peanut Allergy, or LEAP, study, researchers have found that children with severe eczema who were colonized with the bacteria were significantly more likely to have a specific food allergy.

In LEAP, 640 children aged 4 to 11 months with severe eczema, egg allergy, or both were randomly assigned to consume or avoid peanuts until 60 months of age. The study found that the early introduction of peanuts significantly reduced the frequency of the development of peanut allergy. During the study, researchers documented children’s eczema severity and tested for S. aureus colonization at four different time points.

“This design provides a unique opportunity for the detailed investigation of the relationship between S. aureus and food allergy,” the researchers wrote.

In a secondary analysis of LEAP and a 12-month extension of that study, called LEAP-On, researchers investigated the association between S. aureus colonization and specific immunoglobulin E production to common food allergens in early childhood — such as milk, eggs or peanuts — independent of eczema severity. They also sought to determine the association of S. aureus colonization with eczema severity and persistence.

They found that although S. aureus colonization was associated with eczema throughout the study period, children who were colonized at ages 12 and 60 months demonstrated eczema deterioration.

Colonization with the bacteria at any time during the study was linked to increased hen’s egg white and peanut specific IgE levels. Furthermore, children colonized with S. aureus experienced persistent egg and peanut allergy at ages 60 and 72 months. These associations persisted regardless of eczema severity.

“This is significant because most children with egg allergy usually outgrow this at an earlier age,” study author Olympia Tsilochristou, MD, a clinical research fellow at King’s College London, said in a press release.

The researchers wrote that the relationship between eczema, S. aureus colonization and food allergy could be important in providing food allergy interventions.

“We do not know yet the exact mechanisms that lead from eczema to food allergy,” Tsilochristou said. “However, our results suggest that the bacteria S. aureus could be an important factor contributing to this outcome.” – by Katherine Bortz

Disclosures: Tsilochristou reports receiving grants from the Clemens von Pirquet Foundation in Geneva, Switzerland, during the conduct of the study. Please see the study for all other authors’ relevant financial disclosures.

Reference:

Du Toit G, et al. N Eng J Med. 2015;doi:10.1056/NEJMoa1414850.

Tsilochristou O, et al. J Allergy Clin Immunol. 2019;doi:10.1016/j.jaci.2019.04.025.

    Perspective
    Bob Lanier

    Bob Lanier

    It is an exciting time in pediatrics, with new monoclonal antibody treatments for eczema having such a profound effect. Children with horrible eczema for a lifetime can suddenly look totally normal with incredible improvements in quality of life. But we are still flummoxed by why allergy — particularly to food— occurs with many cases of the condition despite either avoidance or early feeding. Food allergy and eczema may have more in common than we thought.

    The association of S. aureus with eczema is one such basic issue where research is still ongoing despite decades of knowledge. We have always considered S. aureus colonization a comorbidity of inflamed skin. To consider a causative role in IgE sensitization is a unique concept that has practical applications.

    • Bob Lanier, MD
    • Clinical professor, pediatric immunology
      University of North Texas Health Science Center
      Director, North Texas Institute for Clinical Trials
      Distinguished fellow, ACAAI

    Disclosures: Lanier reports consulting for Merck and Regeneron.