The Allergy Authority - helping you treat your allergies

This year more than 50 million Americans will sniffle, wheeze, cough, or scratch their way through a bout of allergies. Some suffer from short-lived seasonal allergies, while others suffer all year long-usually in response to foods, pets, or the dust mites that take residence in all of our mattresses and pillows. An unlucky few will suffer from a combination of the two. Below, Dr. Beth Corn, of the department of Clinical Immunology at the Mount Sinai Medical Center in New York City, talks about who gets allergies, how to know for sure when it's allergies, and the rare occasions when they can be life threatening.

What are allergies, and why do they happen?
An allergy occurs when your body sees an ordinary substance as foreign, and the immune system tries to combat the substance. Certain chemicals in the body are released in response to the substance, and these chemicals actually cause the release of other chemicals, which cause symptoms like itchy eyes, runny nose, post-nasal drip, itchy ears and in some cases, even asthma. The foreign substance could be tree pollen, grass, ragweed, cat, dust, a certain food, or any number of other ordinary substances that the body somehow identifies as foreign.

Are there different types of allergies?
Many people have seasonal allergies, which is commonly referred to as 'hay fever'. The reason that it has this name is because about 150 years ago, the hay-harvesting season was in the spring and people thought that these symptoms were a response to the hay. But in actuality the symptoms are caused by grass and trees. There are other seasonal allergies, like the fall allergies, which are the result of ragweed and weed.

The other type of allergy is called a chronic, or 'perennial' allergy, which means it can occur all year. Allergies to dust mites, molds and pet allergies are all perennial allergies, because the sufferer can be exposed all year long.

Some people have both perennial and seasonal allergies. So they inch through the year with their perennial allergy, and then get hit with the seasonal allergy, and the symptoms compound each other.

Is there a tendency for allergies to run in families?
If you have one parent who has allergy, you have a 30% chance of having allergy yourself. If you have two parents, then the odds go up. And then there are some people who have allergies but there is no family history.

Can a person have an allergy for a long time and not know it?
Sure. People can walk around with what they think are cold symptoms for five years and just assume it's a cold. Then someone might say to them, "Maybe this is an allergy." And they go and they get tested and, lo and behold, they have dust mite allergy. So it is certainly possible. If you or someone you know is having repeated symptoms, then it's time to go see a doctor. Nobody should be walking around with a cold for four weeks.

How can people be sure they have an allergy?
If you're having the same symptoms every fall, chances are that you're not just getting a cold every fall. There's a good chance that it's due to ragweed and weed allergy. If you're waking up every morning and you feel congested and swollen, chances are it's an allergy to the dust mites that live in the bed. If every time you're exposed to a cat you start to feel a little short of breath or have itchy eyes or a runny nose, then chances are it's an allergy to the cat.

A primary-care physician can determine that someone has an allergy based on the symptoms and the scenario. But I think most primary-care physicians would refer patients to an allergist to fine-tune the treatment.

What lifestyle changes can be made to control allergies?
The first step of treatment is to identify the cause of the allergy, and learn to avoid it. For instance, it's important to keep a very clean environment to minimize dust mites in your home. Dust mites live in everyone's mattress and pillow. But we recommend that patients who are dust-mite allergic purchase coverings for their mattress and all the pillows on their bed to lock in the dust. We also recommend that patients minimize dust-collecting objects in their bedroom. They should minimize the number of books, stuffed animals and carpets.

Are allergies dangerous?
Anaphylaxis is a very severe allergic reaction that affects a number of areas of the body. It can cause a blood pressure drop, throat closure, wheezing, or hives all over the body. When all of this happens at once, this is called anaphylaxis. If someone is having an anaphylactic reaction, they have to receive a shot of adrenaline or epinephrine. They're also given antihistamines and steroids.

Are some people at higher risk for anaphylaxis than others?
It's kind of a tricky answer, but people who have had an anaphylactic reaction are probably at higher risk to have a subsequent anaphylactic reaction, but just because someone has allergies does not mean that they're going to have an anaphylactic reaction.

Is there anything that someone who has had that type of reaction can do to prevent future reactions? Anyone who has had an anaphylactic reaction in the past-whether it be to a bee sting or to a food-should try to avoid being exposed to bees or to the food that caused it. And this person should walk around with an anaphylaxis kit and an epinephrine pen, which is called an EpiPen, which is just adrenaline. They should also keep antihistamines and steroids with them.