An allergy occurs when the body overreacts to an allergen or 'trigger' that is typically harmless to other people. Examples of allergies include hayfever, asthma, eczema, hives and food allergy. Allergies are very common - it’s estimated one in three people have some sort of allergy. It is also believed that allergy cases are rising. 


The symptoms of an allergy range from mild to severe. The most severe type of allergic reaction is anaphylaxis, which may cause death without prompt medical attention. In most cases, effective treatments are available to manage or treat allergy symptoms.



An allergy occurs when a person's immune system reacts to substances in the environment that are harmless for most people. These substances are known as allergens. Common allergens include:  

* Food: crustaceans, eggs, fish, milk, peanuts, tree nuts (almonds, cashews, pecans and walnuts), food additives (MSG), sesame and soy products  

* Plants: pollen from grasses and plants  

* Medicines: ­­ prescription drugs (such as penicillin), over-the-counter medicines (such as aspirin) and herbal preparations  

* Insects: dust mites and the venom from bees, ticks and wasps  

* Moulds: mushroom and mould spores  

* Animal dander: fur and skin flakes from domestic pets like cats and dogs  

* Chemicals: industrial and household chemicals and chemical products such as latex rubber.


An allergen enters the body and is wrongly identified by the immune system as a dangerous substance. In response, the immune system makes an antibody to attack the allergen. These are specific antibodies of the IgE (immunoglobulin E) class. When an allergen is found, IgE antibodies trigger a cascade of immune system reactions, including the release of chemicals known as mast cell chemicals. These are substances that the body normally uses to destroy micro-organisms. The most common of these is histamine. In small amounts, histamine causes itching and reddening of the local area. In large amounts, the nearby blood vessels become dilated and the area swells with accumulated fluid.

This can happen in the:

* Nose and/or eyes: hay fever (allergic rhinitis/conjunctivitis)  

* Skin: eczema, rash, hives  

* Lungs: asthma, constriction of windpipe


A substance that is an allergen for one person may not be for another - everyone reacts differently. Also the severity of the reaction can vary widely.



Fortunately you do not have to put up with the symptoms of an allergy without help. With the advice of your pharmacist or doctor, these medications can help:  

* Antihistamines: these reduce many irritating and uncomfortable symptoms. Non-sedating antihistamine tablets (e.g. Claratyne, Zyrtec and Telfast) rarely cause drowsiness and are available from pharmacies without a prescription. Antihistamine nasal (e.g Azep) and eye sprays (e.g Livostin) can also be used.  

* Intranasal corticosteroid nasal spray (e.g. Flixonase, Beconase):  are very effective for treatment of moderate to severe allergic rhinitis (hay fever) when used correctly.  A prescription may be required for stronger dose intranasal corticosteroid nasal sprays 

* Medicated eye drops: these help with eye redness and irritation.


If the sufferer is having trouble breathing or feeling faint they may be going into anaphylactic shock. This is life threatening and it’s essential to get them to a doctor or call and ambulance.



Anyone can develop allergies at any age. However people with impaired immune systems or immune system conditions like HIV are more susceptible. The likelihood of developing allergies is also increased if other family members suffer from an allergy or asthma.



Identifying and avoiding the allergen will prevent you from getting the symptoms. In some cases this is obvious and you may be able to narrow down the source yourself. However in others it may take a medical investigation by an allergist or clinical immunologist to narrow this down with either skin prick or blood tests or a food avoidance regimen to discover the source of the reaction.