What is an allergy?

An allergy is your body’s immune systems over sensitivity and over-response to a harmless foreign substance such as plant pollen, a certain food, a medicine or any one of many other substances.28 The immune system responds to this ‘foreign’ substance by triggering an allergic reaction where histamine and other chemicals are released. These produce the allergic symptoms of inflammation, which are – swelling, mucous production, itching, rash, hives, or other symptoms depending on the type and location of the allergy.28

What are the most common allergy symptoms?

The most common allergy symptoms are sneezing, a runny nose, itchy eyes, wheezing, coughing, itchy skin rash. The type of symptoms you experience depends on what you’re allergic to and how you come into contact with it. For example, you may have difficulty breathing if you inhale pollen, or develop dermatitis if you apply a lotion containing a chemical you’re allergic to, or nausea and vomiting if you eat a food that you’re allergic to.

What is hay fever?

“Hay fever” is an incorrect term. Hay is not a usual cause of this problem, and it does not cause fever. Early descriptions of sneezing, nasal congestion, and eye irritation while harvesting field hay promoted this popular term.24 

Allergic rhinitis is the correct term used to describe this allergic reaction, and many different substances cause the allergic symptoms. Rhinitis means “inflammation of the nose” and comes from the word rhino, meaning nose24 and can cause can cause symptoms such as sneezing, itching, a blocked nose, a runny nose and a postnasal drip (when mucus drains from the sinuses down the back of the throat).25 

Allergic rhinitis that occurs during a specific season is called “seasonal allergic rhinitis.” When it occurs throughout the year, it is called “perennial allergic rhinitis.”24

What are hives?

Hives (also known by the name urticaria) affect about 20 % of people at some time during their lives. It is a reaction that can be triggered by many substances if you are allergic to them and usually starts as an itchy patch of skin that turns into swollen red welts or itchy bumps26when, when pressed, the centre of the red hive turns white.26 

Hives can last anywhere from minutes to months or even years. They often resemble insect bites but can appear anywhere on the body disappearing and reappearing over short periods of time.26

Treatment consists of avoiding the triggers that cause the condition and seeing a doctor who will help you work out what triggers the reaction.26

What does the word allergy mean?

The origin of the word ‘allergy’ comes from the Classical Greek word ‘allos’, then the German word ‘allergie’. It is a noun with the following meanings:

  • A hypersensitivity to a specific substance (such as food, pollen, dust etc.) or condition (as heat or cold) which in similar amounts or degrees is harmless to most people: it is manifested as a physiological disorder
  • A strong aversion

Is it a cold or an allergy?

The symptoms of allergies can be very similar to those of a cold but there are some differences.

Both allergies and colds cause a blocked nose, runny nose, sneezing, and/or a cough.

Seasonal allergies may cause itchiness of the nose, roof of the mouth, back of the throat and eyes, however, a cold does not. A cold may cause body aches, fever and a sore throat, however, an allergy does not.22 

What is pet dander?

Most people believe that that the airborne fur/hair of pets causes allergies but it is the airborne saliva and urine-derived proteins that cause allergies from pets. Glands in the skin of the pet also produce these allergies and pets shed the upper layers of their skin cells.29Dander is the name used for the microscopic particles of skin shed by pets and it is these tiny flecks of skin that can cause allergic reactions, as well as the proteins found in the saliva, urine and faeces.25 The fur may be coated with allergen proteins deposited from dried saliva when the pet licks its fur but the skin (dander) is the major source of the pet allergen.29

Pet dander can be found on clothing, bedding, upholstery, cars, rugs – in fact anywhere where the pet has been present and may have deposited dander or where the dander has stuck to clothing and the clothing has been present (for example on public transport, in the office or at school). It can remain in a home for up to six months or more after the pet has been remove.29 

Why do my ears itch when I wear certain earrings?

Nickel is a leading cause of allergic contact dermatitis and it is likely that your earrings contain an amount of nickel in them. Nickel is a silver-coloured metal that is mixed with other metals to make coins, jewellery, eyeglass frames, home fixtures, keys and other common items.38 It is the most common metal that people are allergic to.38 In people allergic to it, nickel causes an itchy red rash.

More women than men have an allergy to nickel and this is probably because more women have pierced ears compared to men. Research has shown that one of the most common risk factors for a nickel allergy is body piercing.38 If you have a nickel allergy, make sure that all your jewellery is nickel free. If you have to wear something with nickel in it, make sure that there is a barrier between the item and your skin (clothing for example).38 If you do develop a rash, speak to your Pharmacist or Doctor who will recommend a treatment for you.

Is it conjunctivitis or an eye allergy?

The chances are that if both your eyes are affected – it is an eye allergy. Unlike pink eye, eye allergies are not infectious and they will not harm your eyes. The term for an eye allergy is allergic conjunctivitis and the conjunctiva of the eye becomes inflamed.37 

Allergens that affect the eye are typically the air borne allergens like pollen and mould spores, animal dander and the house dust mite.37The most common symptom occurs when the small blood vessels widen and the eyes become pink or red. Some people experience pain in one or both eyes. Other symptoms include swollen eyelids, a burning sensation, and sore or tender eyes.37Treatment includes avoiding the allergen and applying antihistamine eye drops or taking antihistamine pills or capsules.37 

What is atopic eczema?

Atopic eczema is also known as atopic dermatitis and is an itchy rash or disease of the skin. Eczema is inherited. The skin of a patient who has atopic eczema reacts very easily to irritants, food and environmental allergens such as pet dander and house dust mites. The skin becomes red, flaky and very itchy and bacterial infections can also occur. The skin on the inside of the elbows and the back of the knees are the most common sites for this condition. It most often starts in childhood or infancy and may last until adulthood.

Atopic eczema often occurs with other allergic conditions such as rhinitis (hay fever) asthma and allergic conjunctivitis. There is no cure for the condition but it can be managed by preventing the allergen and using allergy medicines – this is best treated by a doctor.

What is anaphylaxis?

Anaphylaxis or allergic shock can be life threatening and it is an allergic reaction that can affect a number of our organs at the same time. Anaphylaxis is usually caused by foods, medications and venom/poison such as a bee sting. Airborne allergens rarely cause anaphylaxis.

The most typical symptoms are – hives (urticaria), nasal congestion, runny nose, itchy eyes, swelling of the tongue and or throat which leads to difficulty breathing, abdominal discomfort, nausea, vomiting, shortness of breath, wheezing, coughing, low blood pressure which leads to light-headedness, passing out or shock.

Anaphylactic shock is serious and is a life threatening condition

Why do some people get allergies while others don’t?

It is not fully understood why some people get allergies and others do not. Factors such as family history and genetics do have a role.34 

Children born by Caesarean sector have more chance of being allergic than those born by natural childbirth and being exposure to tobacco smoke also increase the risk. Boys are more likely to be allergic than girls.34 

Allergies can develop at any age but food allergies, for example, start at a young age and are often outgrown. Environmental allergies (such as hay fever) can develop at any time and the initial exposure or sensitisation may even occur before birth while in the womb. People can also outgrow allergies over time.34 

Does stress cause allergies?

No – stress does not cause allergies but it can make existing allergies worse. Stress is the body’s reaction to conflict or other situations that interfere with our normal balance of life.

Almost all our body’s systems make adjustments in a stressful situation including the digestive system, the cardiovascular system, the nervous system and the immune system. One of the things that happens is that out body releases numerous hormones and other chemicals – one of those is histamine. The release of histamine can result in allergy like symptoms and therefore it can make an existing allergy worse.35

What does ‘hypoallergenic’ on a product label mean?

“Hypo” means “under” or “less than,” so “hypoallergenic” means a product is not as likely to trigger an allergic reaction. Many products that we use, such as cleansers and soaps, deodorants, makeup, and even mouthwash, have ingredients that can irritate the skin or act as antigens (substances that act as an allergy trigger). When your skin is exposed to these ingredients (often fragrances and chemicals used as preservatives) they can lead to a condition called contact dermatitis. Contact dermatitis appears as areas of redness, itching, and swelling on the skin, and sometimes as a rash or blisters.

Many manufacturers of cleaning supplies and especially cosmetics, now advertise their products as being “hypoallergenic,” meaning the products do not contain ingredients that are known to cause irritation or allergic reactions. These manufacturers are not required to prove the claim that their products are hypoallergenic though.

What is a pollen count and how is it related to allergies?

A pollen count measures the amount of pollen in the air. They are sometimes mentioned or even shown in weather reports and are usually reported for mould spores and 3 types of pollen: grasses, trees and weeds. The count reports the number of pollen grains per square meter of air collected over a 24 hour period and is measured as absent, low, medium or high.

When the pollen count is low – it usually means that only people who are extremely sensitive to pollen will experience allergy symptoms while if it is reported as high, it means that most people with any sensitivity to pollen will experience allergy symptoms.

How common are allergies?

Allergies are very common and approximately 10-30% of people are affected by allergies. The prevalence of allergic conditions has increased significantly over the last 20 years and continues to rise34 – in fact, for example, 1 in 5 people in America have either allergy or asthma symptoms.34

Family history or genetics plays a large role in whether you will develop an allergy or not and this risk will be higher if your parents or siblings have allergies.34 If one of your parents is allergic you will have a 33 % chance of developing an allergy and if two of your parents are allergic then the chance of your developing allergies will rise to 70 %.34

How do I know if I have allergies?

Typical symptoms of allergies include but are not limited to: sneezing, a runny nose, itchy eyes, wheezing, coughing, itchy skin rash.27 You should rule out if you have a viral or bacterial infection, as some of the symptoms could be similar.22 

If you think that you do have an allergy, you should visit your Pharmacist or Doctor who would be able to give you advice and help you with a treatment. Avoiding the allergen is the most effective way of managing an allergy but this is not always possible.33 Common treatments may include antihistamine preparations which are available in pill, capsule or spray formulation as well as a cream for a skin allergy while decongestants will help with a blocked nose.33 

Is a peanut allergy the most common food allergy?

No – a peanut allergy is the food allergy most likely to result in an anaphylactic reaction – this is a severe potentially fatal allergic reaction. A small percent of the population (0.6 %) is affected by peanut allergy and the most common food allergies are caused by fruit and vegetables.32 

Peanut allergies are more common in people who have other allergies or have a family history of allergies, including having a brother or sister with an allergy.32 An allergic reaction to peanuts usually occurs within 20 minutes of exposure.

Symptoms of a peanut allergy include – skin redness, itching, hives, and if it is more severe, then wheezing, difficulty in breathing, cough, nausea & vomiting, diarrhoea, low blood pressure, increased heart rate, dizziness, fainting and behavioural changes especially in children.32

What are house dust mites?

House dust mites are microscopic arachnids (resembling spiders) and are not visible to the naked eye. Having house dust mites in your home does not mean that your home is dirty – usual cleaning methods do not get rid of them. They have sticky pads at the end of their feet and attach themselves to fibres and live deep within carpeting, upholstery and mattresses. Dust mites get their food from human secretions and skin cells that we shed, and they get their water from humidity. These little creatures prefer more humid conditions and are rarely found in dry climates.

The most bothersome dust-mite allergens are the digestive enzymes found in the faeces of the dust mite. An allergy to dust mites is common and about 10 % of the population is allergic to them while about 80% of asthmatic children are allergic to dust mites.

How can I get rid of household allergens?

There are 7 allergens that may be hiding in your home!

  • Dust – replace carpets with linoleum or wood. Vacuum regularly.
  • Dust mites – wash all bedding in hot water every 7-10 days.
  • Pet dander – bath pets regularly, use an air filter and use allergen resistant bedding.
  • Pollen – shower or bath before going to bed. Avoid going outside on dry, windy days. Keep windows and doors closed.
  • Cockroaches – keep food in sealed containers. Don’t leave pet food out too long. Clean behind areas like your stove and fridge.
  • Mould – remove house plants. Clean shower curtains, bathroom windows and other areas prone to dry rot.
  • Endotoxins – these originate from bacteria that can live in dust. Avoid by taking the same precautions as for dust and moulds.