TRACKER - Trajectories of Allergy in Children in Real-Life Databases

Atopic trajectories refer to the natural history and course of the development of allergic diseases. Most allergic diseases have their onset in early childhood, often preceded with atopic dermatitis (AD) and later this is followed by the development of food allergy, asthma, and/or allergic rhinitis (Hill & Spergel, 2018). One of the risk factors of the development of AD is the dysfunction of the skin barrier, e.g., caused by various factors as irritants, microbes, genetic factors, allowing epicutaneous penetration of allergens leading to sensitization, specific IgE antibody and an increased production of Th2 cytokines (Cork et al., 2009). Subsequently leading to the development of food and inhalant allergies. Importantly, the natural course of AD can be divided into different subphenotypes of AD, such as transient AD, early-onset-persistent AD, early-onset-late-resolving AD, early-onset-early-resolving AD, mid-onset-resolving AD, and late-onset-resolving AD (Paternoster et al., 2018). These different subphenotypes of AD could possibly be associated with different atopic trajectories. Roduit et al., 2017 found that there was a strong increase in the prevalence of asthma and food allergy in children by the age of 6 years who were identified with early phenotypes of AD. Bieber et al., 2017 concluded that phenotypes of AD should be treated individually rather than a ‘one-fits-all’ model which could better prevent the development of atopic disorders. Studies on the different atopic trajectories from AD towards food allergy, asthma, and allergic rhinitis from infancy throughout childhood into adulthood are sparse, but necessary, in order to better understand the underlying mechanisms and to provide opportunities for individual preventive and treatment strategies. We will investigate AD phenotypes in early life and the atopic trajectories towards food allergy, asthma, and allergic rhinitis in childhood throughout adulthood.