The prospect of balmy days and the countryside filling with flowers sounds simply idyllic, but to a hay fever sufferer it screams excess amounts of air-bound pollen destined to cause them havoc for weeks to come.

Hay fever is a seasonal allergy, which is caused by pollen from grass, flowers, trees, weeds and plants. First-time sufferers can often mistake hay fever for a summer cold, but for long-term sufferers once their sneezing begins they know the hay fever season is in full swing.