Hay fever, which is also called allergic rhinitis, is a common allergic condition that is usually triggered by pollen and may be seasonal. Some patients react to indoor allergens, like dust mites or pet dander, and have symptoms all year. If you have hay fever, you may will feel like you have a chronic cold.
Like other allergic reactions, hay fever occurs when your body identifies some substance in your external environment as being harmful. Your immune system produces antibodies to that substance, and then you experience symptoms each time you inhale or ingest some of it.
You may be more likely to have hay fever if you have other types of allergies, including eczema and asthma. Hay fever may be hereditary, and you are more likely to have symptoms if another family member does. Some studies link hay fever to mothers who smoke during your early childhood.
Allergic rhinitis, or hay fever, produces symptoms similar to having a cold. These include nasal congestion, sneezing and itchy, red eyes.
One way to tell the difference between hay fever and a cold is to look at your mucus production. Allergy sufferers will have clear mucus, while a cold will make you have thick green or yellow discharge.
Postnasal drip from excess mucus can irritate the throat and cause coughing and sore throat.
Hay fever occurs when the body reacts to pollens which it is allergic to. Pollens are fine powders which come from plants; often they cannot be seen by the naked eye, but they can enter the body via the mouth, nose, eyes and throat and trigger a reaction from the immune system.
Ultimately, the reason why the body reacts to pollen is because the immune system mistakenly identifies it as a harmful substance. It then creates antibodies which are designed to fight off the substance. Whenever you come into contact with the same substance, the antibodies tell the immune system to release histamines into the bloodstream which are responsible for the symptoms of hay fever.
It isn’t clear why some people are allergic to pollens when others are not. Some people may react particularly badly to certain types of pollen than others. People with asthma and eczema are more likely to develop hay fever than others, and there also seems to be a genetic link; those with a family history of asthma or allergies are more likely to have hay fever themselves.
Avoiding the allergens that trigger symptoms is the best way to treat hay fever, but that is not always possible. You can minimize exposure by staying indoors, keeping your windows closed and wearing glasses or sunglasses when you do go outside. If you react to indoor allergens, try to keep what bothers you out of the house. Use furnace filters to remove allergens in the air and wash bedding regularly in hot water.
You may also find some relief with over-the-counter antihistamines, which help reduce sneezing, itching and congestion. Other allergy medications may be prescribed by your doctor.
Some patients experience severe allergies that can be treated with low-level exposure to the allergen over time. This usually takes the form of allergy shots, where a tiny bit of the allergen is injected weekly or bi-weekly until you reach a maintenance dose. Then, the injection is given every few weeks or every month. This treatment can continue for years until the allergic reaction is reduced.