All of us are exposed to different potential allergens throughout the day. Where you are when sneezing starts, as well as the time of day, can provide clues to identify the cause. For example, if you suffer from airborne allergy symptoms when you are out in countryside then pollen is most likely a trigger. If this affects you for a large part of the spring and summer, then you may be allergic to more than one type of pollen. There are several triggers that can affect you in the garden. Mowing the lawn throws grass pollen into the air, digging or potting out plants can release mould spores from the soil.
If you have airborne allergy symptoms at about the same time each year, then the chances are you have hayfever and are sensitive to pollen or mould spores. The time of year might give you a good indication of which types of pollen are causing the problem. Hayfever seasons vary from year to year depending on the weather.
Moulds and fungi reproduce by sending out spores into the air. About 20% of people who suffer from airborne allergies are affected by mould spores. Moulds can grow anywhere, indoors and out. They prefer damp conditions - the kitchen and bathroom, in wooden window frames, the soil of houseplants and under wallpaper. Outside, there are plenty of moulds in the soil, in rotting wood and leaves, grass cuttings and compost heaps.
house dust mites
It's actually not dust that causes the problem, but a tiny creature called the house dust mite. House dust mites are almost always present in house dust, even in the most clean and tidy homes. In some ways they serve a useful purpose in disposing of skin flakes in house dust. They mostly like damp and dusty spots found somewhere in nearly every home. The house dust mite or, in fact, its droppings, are the most common trigger of airborne allergy.
It is often not the fur itself that causes the allergy problem. Dander, the mixture of small particles of fur, skin scales (like dandruff) and saliva is the actual cause. Cats, in particular, cause allergies but dogs and rabbits can also trigger the itching and sneezing of airborne allergy. Because cats groom themselves so thoroughly, the saliva finds it way onto carpets, furniture and other surfaces.
In addition to these common allergy triggers there are others that can make life difficult for airborne allergy sufferers.
High concentrations of nitrogen dioxide, sulphur dioxide and other chemicals that find their way into the atmosphere can irritate the nose and airways even in those who do not suffer from airborne allergy.
Air conditioned atmostpheres that suck chemicals, dust and pollution from outside, can make allergic reactions worse. Chemicals, pollution from outside, changes in temperature, low humidity and other factors in the 'sick building syndrome' can increase nasal sensitivity. Even good air conditioning, with efficient air filters that can reduce the level of pollen, will not get rid of all air pollution.