Allergies
Allergies are very common, affecting about one in three New Zealanders at some time in their lives. Some people with allergies only ever have very mild symptoms, such as sneezing or a runny nose, whereas others can have severe symptoms that may be life-threatening. Allergies are a contributing factor to conditions such as hayfever, eczema and asthma.
What is an allergy?
An allergy occurs when the body’s immune system over-reacts to normally harmless substances (called allergens). These allergens may be in the air or on things that are touched or eaten.
The most common allergens in New Zealand are caused by:
Dust mites (their waste products)
Pollen
Animal dander (skin scales or flakes from animal fur or feathers)
Foods - such as peanuts, cow’s milk, soy, eggs, seafood are more likely to cause allergies (although true food allergies are relatively uncommon)
Insect stings
Moulds
Medicines.
How do allergies start?
A person prone to allergies is called ‘atopic’ and the tendency to be allergic can be inherited. Allergies start only if that person is then exposed to a certain allergen (there is a lot of variation in what they could be allergic to).
When a person who is allergic to a particular allergen (for example, pollen) comes into contact with it, an allergic reaction occurs in the body. As part of the body’s response, histamine is released, causing swelling and inflammation which is extremely irritating and uncomfortable.
Symptoms depend on where the reaction occurs; for example, mosquito bites on the skin cause a wheal and flare reaction, whereas allergic rhinitis (hayfever) caused by inhaling pollens into the nose, results in sneezing, a blocked and runny nose, and tickly throat and itchy eyes (also see Hayfever).
Many atopic people are allergic to more than one substance and are prone to developing new allergies, often to things they have not been allergic to in the past.
Anaphylaxis (severe allergic reaction)
Anaphylaxis is the most severe form of allergic reaction and is potentially life-threatening. It must be treated as a medical emergency, requiring immediate treatment and urgent medical attention.
Symptoms of anaphylaxis
Signs and symptoms of anaphylaxis may occur almost immediately after exposure to the allergen or within the first 20 minutes and may include:
Difficulty and/or noisy breathing
Swelling of the tongue, or swelling or tightness in the throat
Difficulty talking or hoarse voice, wheeze or persistent cough
Loss of consciousness and/or collapse
Young children may turn pale, become unresponsive and go floppy.
Symptoms can rapidly become life-threatening. Administration of adrenaline is the first line of treatment for anaphylaxis. Once medical attention is available, other medications may also be needed.
See Your Pharmacist or Medical Professional
See your pharmacist or doctor if you think you may be suffering from an allergy.
Your pharmacist can give general advice and suggest suitable products for symptom relief and/or prevention.
Your pharmacist can also advise on correct use of adrenaline auto injector devices.
You may need to see your doctor or an allergy specialist for diagnosis or to identify the allergen(s).
You should also consult your doctor to develop an action plan and get information on management of any allergies.
Treatment Tips
Identifying the allergen(s):
Keeping a food diary or written record of your diet and any symptoms for several weeks may be helpful in identifying a particular food allergen, and can be helpful to show to a doctor or specialist
If you have had a clear reaction to a particular food, try to avoid that food until you have seen your doctor
To be certain of what you are allergic to, you may need skin-prick tests, which are carried out by a doctor or allergy specialist to check your response to different allergens.
Managing the allergy:
Avoid the allergen if possible (see below for detailed advice)
It is advisable to wear a medical bracelet or necklace (e.g., Mediband, Medic Alert) that gives details of your allergy(ies)
People with allergies should always tell a doctor, pharmacist, or other health professional of their allergies before starting any new treatment, including ‘natural’, herbal products or supplements
People who have life-threatening allergic reactions need to carry adrenaline with them at all times and be trained in the correct use of adrenaline
for children with serious allergies attending school or day-care, caregivers should consider providing a poster complete with their child’s photograph that clearly outlines their child’s condition and treatment (see www.allergy.org.nz for more on child safety).
Avoiding specific allergens
Dust mites: Use dust mite covers on all bedding; wash and air all bedding in sunlight once a week. Replace carpets with hard flooring and mop rather than vacuum. Regularly freeze stuffed toys overnight to kill any mites. Select vinyl or leather furniture rather than cloth. Ensure good house ventilation and avoid moisture build-up.
Pollen: Keep the garden free of highly allergenic plants; stay indoors when pollen count is high (e.g., windy days); get someone else to mow your lawn; wraparound sunglasses stop pollen getting into your eyes; shower and wash hair at night to wash away any pollen.
Animal dander: Keep pets outside and choose breeds that are hairless or shed low amounts of fur.
Skin allergies: Avoid strong soaps, perfumes and products that may irritate.
Food allergies: Avoid allergy-causing foods but maintain a balanced diet - see www.mfd.co.nz for a list of safe foods.
Insect bites and stings: Wear footwear outdoors and cover body with clothes; avoid sudden movements if bees or wasps are around; avoid wearing perfume as it can attract insects; wear gloves and insect repellent when gardening.
Treatment Options
The best management for allergies is to avoid the allergen; however, this is not always possible.
Treatment options include antihistamines and corticosteroid nasal sprays (which both work to treat the allergic reaction), decongestants (which work to relieve the symptoms rather than the allergic reaction), and emollient or corticosteroid creams to help soothe inflamed skin.
People at risk of severe allergic reactions should carry adrenaline with them at all times.
Immunotherapy may be a more permanent option for people with allergies, though the course of treatment can take some years to complete.
Treatment of Anaphylaxis (severe allergic reaction)
Adrenaline
[PHARMACIST ONLY]
e.g., adrenaline auto-injector device (Anapen, Epipen)
Two different strengths are available for each pen (junior/adult)
People with allergies/caregivers should be familiar with how to use auto injector devices before they are needed (and devices available have slightly different methods of use)
Training pens are available for practice
Inject into the upper thigh, not the buttock
Always call an ambulance after the adrenaline has been given, so the person can have further follow-up
Check regularly that any adrenaline auto injectors you keep for emergencies are not past their expiry date.
Treatment of Allergy
Oral antihistamines - newer non-sedating antihistamines
[PHARMACY ONLY]
e.g., Aerius Tablets, Arrowcare Fexofast, Arrowcare Zetop, Claratyne, Lorfast, Razene, Telfast range, Xergic, Zyrtec tablets and liquid
Some of these products are available as syrups for children – check correct doses for different age groups
Helps control total body itch and inflammation
Non-sedating medicines do not usually cause drowsiness; however, some people may be more sensitive than others
Do not drive or operate machinery if you feel drowsy.
Other Medicines
For detailed information on other antihistamine options, nasal corticosteroids and decongestants, see Treatment Options in our topic on Hayfever
Also see Dermatitis/Eczema for information on topical corticosteroids and other products to soothe inflamed skin.
Other types of Allergy Treatment
Immunotherapy
An allergy specialist can advise you about a course of immunotherapy (desensitisation or hyposensitisation).
This involves a series of injections that gradually increase exposure to an allergen and stimulate your immune system to develop a resistance to the allergen.
It usually requires regular injections over a long period (up to five years, for some types of allergies).
This type of therapy is particularly useful for allergies to insect venom, such as bee or wasp stings.
