What is an allergy?
Allergies are very common and affect about one in three New Zealanders at some stage in their life. There are many different causes of allergies and symptoms can range from very mild to severe and life threatening. Allergies are one of the major factors associated with asthma.
An allergy occurs when a person’s immune system over-reacts to the exposure of a substance (allergen). These allergens are found in house dust mites, pets, pollens, foods, moulds and insect stings, etc. An allergen for one person may not be a problem to another person, and everyone reacts differently.
The most common causes of allergic reactions in New Zealand are:
• Dust mites
• Grass pollens
• Cats and other animals,
• Food, such as peanuts, cow milk protein, egg and soy
• Insect stings
Airborne triggers are commonly dust mites, pollen, mould spores, cat and dog allergens. Skin contact or inhalation of an airborne allergen can lead to symptoms of skin rash, swelling of the eyes, hay fever and asthma. Airborne allergens are not often a trigger for anaphylaxis.
Food allergens are most often ingested. Any type of food can trigger an allergic reaction. The majority of allergic reactions are triggered by egg, cow milk, peanuts, tree nuts, soy, wheat, seeds, fish and shellfish.
• Egg and dairy are the most common triggers in infants
• Peanuts, tree nuts and seafood are the most common triggers in older children, teenagers and adults
Food may trigger reactions that range from localised contact reactions of the lips/mouth/tongue, through to generalised reactions, including anaphylaxis.
Insect venom is an injected allergen from stinging insects such as bees and wasps. The venom from each of these insects is different, and being allergic to one doesn’t mean you will be allergic to others. They range from localised reactions, which can be large and last for a number of days, to immediate generalised reactions, including anaphylaxis. Because a sting punctures the skin, anaphylaxis can be rapid, within minutes.
Who is allergic?
Specific allergies are not inherited, but the tendency to be allergic is. The potentially allergic infant is one who has one or more allergic parents, grandparents or siblings. The reasons for developing allergies are not entirely known, but any person may develop an allergy at any age.
The best way to prevent symptoms is to avoid what triggers the allergy. The allergic person needs to become very aware of when symptoms develop and take steps to reduce contact with the offending substances.
The Waikato Allergy Clinic deals with a wide range of allergies and can perform skin prick testing at any age to determine which foods or inhaled substances are the likely causes. Based at the Waikato Allergy Centre, Dr Michael Becker and Dr Graham Currie specialise in diagnosing and treating allergies.
Investigation and treatment options include: skin prick tests to environmental and food allergens; blood tests; allergen challenges; hydrogen breath testing for sugar intolerances; desensitisation and immunotherapy programmes.
All methods of investigation and treatment are those recommended by the NZCIAG and Australasian Society of Clinicial Immunology and Allergy (ASCIA).
For more information on the Waikato Allergy Clinic, visit www.victoriacentral.co.nz