Hay fever

What is hay fever?

Hay fever, or allergic rhinitis, is the most common form of allergy.

Allergies occur when the body's immune system incorrectly reacts to something (known as an allergen) that is normally harmless and starts an allergic reaction.

The most common allergens that cause hay fever are pollens, molds, animal dander, and dust mites.

When these things are breathed in, they cause an allergic and inflammatory reaction in the mucous membranes lining the eyes, nose, and throat.

The discomfort caused by exposure to the allergen can be "seasonal", such as tree pollen in April/May, grass pollen in May/June/July, and ragweed in August/ September/October, or "all year-round", such as with pet dander or house dust mites.

Hay fever happens at any age, but usually starts during childhood or early adulthood. It tends to run in families and is often seen in people who also have asthma or eczema.

Hay fever is very common, with about 20% of the population having it at one time or another.

Treatment / What you should do

If you suspect that your child may have allergies, you should check in with your child's doctor.

The doctor may be able to diagnose allergies by reviewing your child's symptoms and medical history along with examining him or her. In some cases, the doctor may order different types of tests to help figure out whether or not someone really has an allergy. These may be blood tests or skin tests.

Allergists, doctors who specialize in allergies, may need to do some of these studies.

The best treatment for allergies is to avoid the substance that the child has an allergic reaction to in the first place.

Often it is not possible to avoid something completely, but you can do a number of things to limit a child's exposure (see Prevention, below) to allergens.

When symptoms persist despite taking these steps, lots of allergy medicines are available.

For example, antihistamines stop allergic reactions before they start. Newer antihistamines do not cause drowsiness, as the older ones did, and some are now available even without a prescription.

Steroids work to decrease the inflammation caused by the allergic reaction, keeping the mucous membranes stable and preventing nasal symptoms.

These medications can be in the form of nasal sprays, eye drops, and pills or liquids taken by mouth (oral). Decongestant nose drops that relieve mucous membrane swelling should not be used for hay fever, because when used for more than two or three days, can actually make symptoms worse; a so-called "rebound" effect.

In some people, allergy shots may be helpful for decreasing allergic reactions. These work by very slowly introducing the child to tiny doses of the allergen. Over time, the person becomes less sensitive when exposed to these allergens, decreasing their allergic reactions. However, this may take three to five years of treatment to work well and it doesn't work the same in everyone.