Hay fever, seasonal allergies, insect allergy
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Hay fever, seasonal allergies, insect allergy Rhinitis (sneezing, blocked, runny and/or itchy nose), conjunctivitis, sore/itchy throat, and even asthma can be triggered by grass pollens in summer, tree pollens in spring, mould spores in autumn and at other times, as well as by exposure plus reaction to many other factors. These all share the same mechanisms as eczema, asthma and urticaria (hives). They are (broadly speaking) part of the single disorder known as atopy, which is associated with a particular form of antibody, IgE. Anaphylaxis (a sudden, severe allergic reaction which causes collapse and can be life-threatening) is also caused by IgE antibodies, and must be borne in mind when dealing with all these diagnoses and in their treatment. Rhinitis and the other symptoms can be triggered by exposure to a wide range of airborne and other factors. Because allergies most often develop at the “portal of entry”, rhinitis is most commonly triggered by airborne factors (“inhalant allergens”; pollens, animal fur, house dust mites etc). |
In recent decades there has been a big rise in reactions to the pollen of rapeseed, which has been widely planted and has irritant qualities. In mainland Europe, but not in the UK, an important pollen allergen is Parietaria Officinalis, an insignificant-looking weed in the Nettle family. It grows on rubbish and out of walls, hence its old English name Pellitory-of-the-wall (in Australia it is known as Asthma Weed). The warmer the climate the longer its flowering season, so sufferers in Sicily for example may get symptoms from February to December. Foods and food additives - things that are swallowed not inhaled - can also cause these problems. One such that is becoming more important is lupin; rhinitis, urticaria etc from allergy to lupin are well-known, but now that lupin flour is being used increasingly in foods there have been several cases of anaphylaxis linked to it. Increasing numbers of people also get rhinitis from exposure to airborne chemical fumes, often together with sore throat and other more general symptoms. |