Environmental allergens: from asthma to hay fever and beyond

Climate change has many impacts on environmental allergens and allergic diseases such as asthma and hay fever. Our knowledge of these impacts has grown considerably over the last 2 decades or so, and the last two and a half years in particular have seen a surge in research published on this topic. This report reviews the work published on climate change, allergens and allergic diseases since 1 January 2013. The review focusses on literature published in the peer-review journal literature, although a number of other prominent sources are also examined. Research of particular significance over the past two and a half years or so includes experimental studies that have quantified changes in allergenicity of pollen under combinations of elevated carbon dioxide and drought stress (for ragweed) and ozone (for Timothy grass). Other extensions of the research on this topic include a number of studies that are considering the impacts of climate change on allergic diseases with increasing sophistication and power. The review also considers recent research related to climate change adaptation in the context of impacts on allergens and allergic diseases. In conclusion, the latest research overall reaffirms this impact as one of the most important impacts of climate change on human health.