Peak sneezin’ season — are more of us than ever affected by hay fever?

Ireland’s high overlap between asthma and hay fever hints at a sizeable population affected, even if precise numbers are elusive

Hay fever is an allergic inflammatory response to airborne pollen from trees, grasses, and weeds. Despite its name, it involves neither hay nor fever. Inhaled pollen triggers an immunoglobulin-mediated hypersensitivity reaction in sensitised individuals, releasing histamines and inflammatory mediators.

It’s a sunny spring morning. The sky is clear, the birds are chirping... and you’re a congested, red-eyed wreck, wondering why your body treats blossom season like a biohazard. Welcome to hay fever, also known (less poetically) as seasonal allergic rhinitis.

If it feels worse each year, you’re not alone. But is this perception, or is there evidence of rising prevalence and severity?