People have immune systems that recognise what is usually part of the body (blood, cells, hair etc.) and what is not (bacteria, viruses, splinters etc.). Sometimes the immune system becomes hypersensitive to chemicals from foods (peanuts, shellfish, nuts, eggs, wheat); animals (dogs, cats); and other materials (grasses, dust, dustmites, medicines).
This causes allergic reactions. For most people, the allergic reaction is hay fever (runny nose and itchy eyes) or hives (a bumpy skin rash). In some people this reaction is severe and causes anaphylaxis, which is an emergency needing immediate injection with adrenaline from an epi-pen.
The Australasian Society of Clinical Immunology and Allergy (ASCIA) recommends that for a severe allergic reaction adrenaline is the initial treatment. For further information, visit the Choosing Wisely Australia website.
Allergies can be treated with antihistamine medicines, and allergy tests might find the cause of the hypersensitivity. If so, it may be possible to have regular injections to stop the body overreacting.
ASCIA also recommends that you should speak to your doctor or specialist about the benefits and safety of allergen immunotherapy or before attempting any allergy testing or treatment. For further information, visit the Choosing Wisely Australia website.
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Last reviewed: August 2014