Suffer from seasonal sniffles? Hayfever is rife during spring and summer, but some allergies last year-round — here’s how to tell the difference
When you suffer from an allergy, your immune system is reacting to a substance that it sees as foreign and harmful to your body. These substances are known as allergens, which can be found in dust mites, pets, pollen, insects, ticks, moulds, foods and some medications.
If you’re atopic, it means you have a genetic tendency to react to these allergens. When atopic people are exposed to allergens they can develop an immune reaction that leads to allergic inflammation (a condition known as allergic rhinitis). This can cause symptoms in the:
- Nose and/or eyes, resulting in allergic rhinitis (hayfever) and/or conjunctivitis
- Skin resulting in eczema, or hives (urticaria)
- Lungs resulting in asthma
These allergies are separated into two categories; seasonal and perennial, which basically means that they either:
- occur seasonally — your symptoms come and go around the same time of year. These are usually reactions to seasonal allergens including tree pollen, grass pollen, and weed pollen. This is usually referred to as hayfever.
- they are perennial — meaning that your symptoms may be chronic and persist year-round, or they may show up intermittently throughout the year. This means you’re allergic to substances that are always in the air, such as mould, dust mites or pet hair.
Both conditions are caused by the same thing — your immune system attacking an invader — but they both differ in duration. Symptoms for both types can include:
- Coughing or wheezing
- Runny nose
- Congestion in your nose and chest
- Itchy throat
- Watery and itchy eyes
Seasonal Allergies: All You Need to Know
Seasonal allergies (commonly called hayfever) are the most common type of allergy. They occur at certain times of the year — particularly during the spring and summer — and are usually a reaction to different types of pollen.
Symptoms involve primarily the membrane lining the nose, causing allergic rhinitis, or the membrane lining the eyelids and covering the whites of the eyes (conjunctiva), causing allergic conjunctivitis.
What is hayfever?
Hayfever happens when your immune system identifies an airborne substance that’s usually harmless (pollen), as dangerous. It responds to that substance, or allergen, by releasing histamines and other chemicals into your bloodstream. Those chemicals produce the symptoms of an allergic reaction.
Symptoms are caused by the body's immune response to inhaled pollen, resulting in chronic inflammation of the eyes and nasal passages. Common triggers of hayfever vary from one season to another.
The term hayfever is slightly misleading because symptoms do not occur only in the summer when hay is traditionally gathered, and never include fever. Hayfever is usually a reaction to pollens and grasses.
Causes of seasonal allergies
Pollen grains can be spread by birds, insects (bees, butterflies and moths), and wind. Most of the pollens that cause allergies are produced by airborne pollen from northern hemisphere grasses, trees and weeds.
Trees are responsible for most springtime seasonal allergies. Birch is one of the most common offenders in northern latitudes, where many people with hayfever react to its pollen. Other allergenic trees in Australia include White Cypress (Murray) Pine. It grows from the western slopes and plains of Eastern Australia across to Western Australia. There are many species of Casuarina or Australian Oak trees, which produce pollen throughout the year and may cause allergic rhinitis symptoms at any time of the year.
Hayfever gets its name from summer hay-cutting season. But the real culprits of seasonal allergies during spring/summer are grasses, such as ryegrass and timothy grass, as well as certain weeds. Other plants that commonly cause allergies include pellitory weed (also known as asthma weed), Paterson’s curse, ragweed and parthenium weed.
Australian native grasses are less likely to cause allergies than those introduced from overseas, exotic or lawn-variety grasses.
By winter, most outdoor allergens lie dormant. As a result, cold weather brings relief to many people who suffer from hayfever. But it also means that people spend more time at home. If you’re prone to seasonal allergies, you may also react to indoor allergens such as mould, pet hair, dust mites or cockroaches.
Perennial Allergies (Year-round Allergies): All You Need to Know
Perennial allergies can occur at any time of year, regardless of the season, and they can also last year-round. Perennial allergies are often a reaction to house dust, which often contain a mix of allergens including mould and fungal spores, fibres of fabric, animal hair, dust mite droppings and bits of insects. Substances in and on cockroaches are often the cause of allergic symptoms. These substances are present in houses all-year-round, but may cause more severe symptoms during the cold months when more time is spent indoors.
Usually, perennial allergies cause nasal symptoms (allergic rhinitis) but not eye symptoms (allergic conjunctivitis). However, allergic conjunctivitis can result when allergens are inadvertently rubbed into the eyes.
Causes of Perennial Allergies
Perennial (or year-round) allergies may be less intense than pollen-based or seasonal allergies. These are most often found indoors and include dust mites, cockroaches, moulds and pets. Pets and moulds can cause a quicker and more obvious response with itching, sneezing, and nasal congestion. But dust mites and cockroaches cause more of a general feeling of nasal fullness, congestion and eye irritation. Asthma can also be triggered by the dust mite and cockroach allergen, which is not always as obvious as a cat or dog allergy.
Indoor allergens are often easier to remove from your environment than outdoor pollens. Here are a few tips to ensure your home is allergen-free:
- Frequently wash bed sheets, pillowcases, and blankets in hot water.
- Cover bedding and pillows with allergen-proof covers.
- Replace upholstered furniture and carpets or vacuum them frequently.
- Remove stuffed toys or any items that collect dust such as books, magazines, ornaments etc.
- Fix water leaks and clean up water damage that can help mould and pests flourish.
- Frequently clean the house, including dusting, vacuuming, and wet-mopping
- Clean mouldy surfaces and any places that mould may form, including humidifiers, swamp coolers, air conditioners, and refrigerators.
- Use a dehumidifier to reduce excess moisture.