Has there been a rise in allergies?
Allergic rhinitis (hay fever), asthma and atopic eczema are among the most common causes of chronic ill health. There is also clear evidence that in the Western world these disorders are increasing in frequency. In Sweden, for example, the number of children with allergic rhinitis, asthma or eczema has doubled over a 12-year period.
What causes allergies?
The development of allergic disease relates to a complex interplay of genetic and environmental factors. Since minimal genetic changes occur over a short period of time, such as the last two decades, we must assume that environmental factors are most likely responsible for this trend. The reunification of Germany offered tremendous insight into the impact of environmental changes on allergic conditions. These disorders were less common in East Germany than in West Germany before reunification, where as since that geopolitical change occurred, the prevalence of allergic problems (except asthma) has increased among children who spent their early childhood in East Germany.