In response to my recent discussion of asthma therapy, Dr. Daniel Ein of Washington Allergy Associates wrote to emphasize how allergy shots (immunotherapy) can help some people who have this condition.

For certain people, allergies are one of the triggers of asthma attacks. Most people who have the allergic type of asthma will also suffer from hay fever, also known as allergic rhinitis, which causes sneezing and watery eyes; or eczema, also known as atopic dermatitis, an itchy, scaly rash on the skin.

However, only a minority of people with hay fever or eczema will also have asthma.

The items that most often trigger asthma in susceptible people include pollens, animal dander, molds and house mites. If you have this type of asthma, allergy shots may cut the number and severity of attacks. They may also reduce your need for asthma medication.

Even for people without allergies, certain irritants can trigger an attack.

These substances include tobacco smoke, fumes, smog, hair spray, perfumes and the like.

In addition, certain medicines may also spark or worsen an attack.

These include aspirin, anti-inflammatory pain relievers like ibuprofen, sulfites (a food preservative) and a class of drugs known as beta-blockers.

Beta-blockers come in pill form as well as eye drops.

Allergy shots work by challenging the body with very small doses of the substance you're allergic to. This tiny amount gives the immune system a chance to build up a tolerance to it, without being overwhelmed.

The dose is gradually increased, until you can take full doses without having a reaction.

At this point, you should be able to handle exposures to the things that you're allergic to, such as pets, pollen and so forth, without suffering an asthma attack.

Allergy shots work only for a minority of people with asthma. They're most often effective in children and young adults, especially in those with other known allergies.

If you have asthma, ask your doctor whether you should be tested to find out whether they're likely to work for you.

Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington. Consultation is a health education column and is not a substitute for medical advice from your physician.

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