A NEW study has provided new insights into atopic dermatitis (AD), a chronic inflammatory skin condition that affects up to 20% of children worldwide. AD is characterised by itchy, eczematous skin lesions and is associated with genetic predisposition, environmental factors, and a weakened skin barrier. While AD commonly begins in infancy, its onset, duration, and progression can vary significantly between individuals.
Researchers analysed data from the Children’s Respiratory and Environmental Workgroup (CREW), a consortium of 12 birth cohorts across the US. The study followed children for seven years, identifying five distinct AD phenotypes based on the timing and persistence of the disease. Around one-third of children were diagnosed with AD at some point, with early-life AD being the most prevalent.
Importantly, the study found strong links between AD phenotypes and the risk of developing other allergic diseases. Children with early AD were more likely to develop food allergies, whereas those with later onset were more associated with allergic rhinitis. Any form of AD was linked with an increased risk of asthma, highlighting the potential for AD to be part of the “atopic march”, the progression from skin inflammation to broader allergic conditions.
Modifiable risk factors played a notable role. Early exposure to pets such as dogs and cats was associated with a reduced risk of persistent AD, while early antibiotic use increased the risk. The influence of pet exposure may relate to its impact on the developing microbiome, which plays a role in immune function and skin health.
The study also observed disparities by race and cohort type, with Black children and those from more recent, high-risk cohorts more likely to develop early and persistent AD. These findings point to the need for further investigation into social and environmental determinants of health disparities.
In conclusion, identifying distinct AD phenotypes and their associated risk factors may offer a path toward personalised prevention strategies and improved management of AD and related allergic conditions.
Reference
Sitarik AR et al. Phenotypes of atopic dermatitis and development of allergic diseases. JAMA Netw Open. 2025;8(6):e2515094.
