Study identifies atopic dermatitis subgroups in children

By Jane Lewis 
Research published in the Journal of Allergy and Clinical Immunology has identified several distinct subgroups of atopic dermatitis (AD) in children in two independent birth cohorts. 

The different risk factor profiles and prognoses of these subgroups could pave the way for ‘a phenotype-driven, more personalised approach’ to the management of childhood AD, the researchers suggest. 

‘Large, longitudinal studies like this are the best way to delineate the natural history of conditions such as atopic dermatitis,’ said Associate Professor David Orchard, Director of Dermatology at Melbourne’s Royal Children’s Hospital. ‘That the subgroups of atopic dermatitis were consistent through two different populations increases the likelihood that they are real and possibly genetically determined.’ 

In the study, the researchers examined AD (defined as a parental report of a typical itchy and/or flexural rash) in a birth cohort of 9894 children from the UK, and a second cohort of 3652 children from the Netherlands. Using statistical analysis to investigate patterns of AD from birth to the age of 16 years (first cohort) and birth to 11 years (second cohort), as well as associations with known risk factors and atopic comorbidity, they found evidence of several different AD subphenotypes with different disease trajectories. 

The most prevalent subgroup, early-onset-early-resolving AD, is associated with male gender, has a favourable prognosis, and is only very weakly associated with asthma in later life. Two subgroups of persistent disease, early-onset-persistent AD and early-onset-late-resolving AD, are most strongly associated with personal and parental history of atopic disease and an AD genetic risk score, and display strong comorbidity with asthma. A fourth subgroup, mid-onset-resolving AD, peaks at 6 years of age, and is not strongly associated with many of the known AD risk factors, but is strongly associated with asthma, the researchers reported. 

‘This provides important information about the risk of various children who present with eczema developing asthma,’ Associate Professor Orchard told Medicine Today. 

‘Giving accurate prognosis for atopic dermatitis is an important aspect of management. Regardless of whether the outlook is good or bad, knowing what lays ahead for a child with eczema is very helpful for parents.’ 

An outcome of minimal to no daily eczema should be the aim for all children, regardless of prognosis, he added.
J Allergy Clin Immunol 2017; doi: 10.1016/j.jaci.2017.09.044.

Picture credit: © Dr Harout Tanielian/SPL