Researchers have identified five subgroups of pediatric atopic eczema, a finding they say helps explain how the condition can affect people differently at different stages of their lives.
In the paper, published online ahead of print in The Journal of Allergy and Clinical Immunology (Nov. 9, 2017), investigators examined the presence of atopic dermatitis (AD) in two birth cohort studies. The studies included 9,894 children from the UK (ALSPAC) and 3,652 from the Netherlands (PIAMA). In both cohorts AD was defined by parental report of a typical itchy and/or flexural rash.
The authors used the data to investigate patterns of AD from birth to the age of 11 to 16 years, as well as with known AD risk factors such as FLG null mutations, atopic co-morbidity, and 23 other established AD-genetic risk variants.
They found that approximately 40% of the children developed eczema at some time in their life. Statistical analysis then revealed five sub-groups, based on when eczema first appeared, and when, if at all, it resolves.
The groups the authors defined were:
Eczema starts in infancy and doesn’t go away
Eczema starts in infancy and lasts throughout childhood
Eczema starts in infancy and goes away in early childhood
Eczema starts in mid-childhood (around 6 years) and goes away later in childhood
Eczema starts in late childhood (11 years-early teens) and then goes away
Senior author Professor Sara Brown said in a press release: “This research study has confirmed that eczema is a very diverse disease, and it’s provided evidence of distinctly different trajectories, including a group that hadn’t previously been recognized, in whom eczema develops for the first time around six years of age and is often associated with asthma."
Professor Brown is the Wellcome Trust Senior Research Fellow in Clinical Science, and professor of Molecular & Genetic Dermatology at the University of Dundee’s School of Medicine.
“We’ve also shown that genetic risk factors contribute to the most troublesome and long-lasting eczema, so these patients can be our focus for future research to improve care,” said Dr. Brown. “It’s also important evidence that we need to consider which subtypes of eczema may respond to which treatments in clinical trials to ensure the right children get the right treatment in future.”
The largest group, comprising approximately one-third of children with eczema, developed the disease soon after birth and mostly grow out of it by their 5th birthday, the authors note.
Approximately one in eight children will have eczema that does not resolve, potentially lasting into adulthood. This population are also more likely to have relatives with eczema, as well as comorbid conditions including asthma and allergies.
In the release, lead author Lavinia Paternoster, PhD, said, “This study brought together two European birth cohorts, PIAMA, from the Netherlands and ALSPAC (or ‘Children of the 90s’) from Bristol.
“The patterns of disease observed in these two cohorts were remarkably similar, which gives us greater confidence in the results.
Dr. Paternoster is the Senior Lecturer in Genetic Epidemiology at the University of Bristol’s Medical School.
“We’ve found some evidence of what might cause children to suffer from different subtypes of eczema, but we still need to do a lot more work to understand this further and work out how we can use this information in the clinic to better help patients,” said Dr. Paternoster.