London: New research shows that regardless of medication and other allergies for grass pollen, hay fever symptoms are worse in the first half of spring than in summer.
Symptoms of hay fever such as a running nose, sneezing and itchy eyes are caused by an allergy to grass pollen, bringing misery to sufferers through spring and summer.
Worldwide, there are over 10,000 species of grass and most of these species are able to cause symptoms in people who have hay fever.
The different species release their pollen sequentially, so that for the sufferer, hay fever (also called `seasonal allergic rhinitis`) can last for the whole three months when grasses are flowering.
Researchers from Leiden University Medical Centre (LUMC) in the Netherlands compared daily pollen counts with daily symptoms reported by hay fever sufferers (with a positive skin test to grass pollen).
LUMC`s Letty de Weger, who led the research, explained: "It is possible that sufferers report their symptoms as milder later in the season because they get used to their hay fever, or that the pollen from late flowering species is less allergenic than pollen from early flowering grass."
The people in the study were also tested for other common allergies including birch pollen, house dust mites, dogs and cats. The study covered the consecutive hay fever seasons of 2007 and 2008.
Symptoms of hay fever definitely matched the concentration of pollen in the air and also the amount of medication taken.
Higher medication use was seen during days with high pollen counts and severe symptoms, while less medication was taken on days with low pollen counts and milder symptom severity.