A closer look at hay fever: past, present and future

As pollen soars and we move from tree pollen season to grass pollen season in the UK, it seems an opportune time to explore the topic of allergic rhinitis – or ‘hay fever’ (Met Office, 2025), which is the most common allergy presentation in the world, affecting 400 million people globally (Waage et al, 2018). Interestingly, the term ‘hay fever’ came into existence because it was originally believed that the symptoms of allergic rhinitis were caused by the smell of hay (Dinning, 2018; London Allergy and Immunology Centre, 2018).

However, while hay season and pollen season coincide, it is the pollen, whether from trees, grass, flowers or weeds, that causes seasonal hay fever, as was officially discovered in 1859 by Manchester physician, Charles H Blackley (London Allergy and Immunology Centre, 2018). Oddly, however, even once the true cause was established, the misnomer ‘hay fever’ has stood the test of time. Hay fever has been written about for the last 200 years, although at the time, allergies were not understood and pioneering research carried out by English physician, John Bostock, was perplexing to people of the day (London Allergy and Immunology Centre, 2018).