London, United Kingdom
Tim Vernon, Lth Nhs Trust
Photograph - Photograph
Hay fever. Conceptual image of a man who is about to sneeze as he inhales pollen grains (red) and other allergens that cause his hay fever (allergic rhinitis). The allergens are causing rhinitis, the inflammation of the lining of the upper nasal tract. This causes watering eyes, a runny nose and sneezing. Pollen grains, here being released from the plants at left, form part of the reproductive process of flowering plants. The pollen grains are tiny, being about 0.1 millimetres across, but many hundreds of millions are dispersed on the wind at peak flowering times during the summer. Treatment of hay fever is with antihistamine drugs.
May 7th, 2013
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