Wellcome Image of the Month: Pollen
Peony pollen grain
For the hayfever sufferer with streaming eyes, a runny nose and a throat so congested you may want to scratch it out, it may be a small consolation that what is causing you so much discomfort is intricately beautiful. This month’s Wellcome Image is a single pollen grain from a peony.
One in five people in Britain are allergic to pollen and experience symptoms of seasonal allergic rhinitis, commonly known as hayfever. This occurs when the body’s immune system registers pollen as a threat and produces an immune response against it.
When you are exposed to pollen, antibodies trigger the B cells of the immune system to secrete their defensive substances, one of which is the chemical histamine. This causes inflammation, including the swelling of the mucus membrane inside your nose, blocking the airway and causing congestion. The swelling leads to the production of excess mucus, which gives you your runny nose. It also causes blood vessels to dilate, which can leave you red-faced.
These uncomfortable, sometimes unbearable, symptoms can be tackled by taking antihistamine drugs. These block the receptors that are the target of histamines, stopping them producing such an irritating reaction.
Or you could relocate to somewhere without the type of pollen you are allergic to, although, although there are 30 types of pollen and 20 types of spore that could cause hayfever. A trip to the Arctic Circle anyone?
Louise Crane, Picture Researcher, Wellcome Images
