Childhood acute urticaria in northern and southern Europe shows a similar epidemiological pattern and significant meteorological influences.

Acute urticaria (AU) is a common condition that often presents in childhood. Although there is a general perception of cyclic annual trends in AU, no one has tried to identify any seasonal variation on its prevalence and incidence, associate environmental influences and impute geographic, ethnic, or even genetic features that may contribute to its onset. We aimed to analyze the influence of climate and geographic parameters on annual fluctuation of AU cases referred to the Emergency Departments (EDs) of Norwich (UK) and Heraklion (Crete, Greece), compare all identifiable potential triggers and severity, and calculate the prevalence and incidence of AU.