By Leanne Jones, M.D. and Bob Marshall, M.D.
For the Renton Reporter

1. What are allergies?

Allergies are abnormal immune system reactions to things that are usually harmless to most people. Substances that cause allergic reactions, such as certain foods, dust, plant pollen, or medicines, are known as allergens.

When these allergens enter the nose, sinuses, and lungs, the body’s immune system can overreact to these particles and release chemicals like histamine and leukotriene which cause an allergic reaction.

Allergic reactions can be mild, like a runny nose, or severe. In rare cases, an allergic reaction can become very severe — this severe reaction is called anaphylaxis (pronounced: an-uh-fuh-LAK-sis). Signs of anaphylaxis include difficulty breathing, difficulty swallowing, swelling of the lips, tongue, and throat or other parts of the body, and dizziness or loss of consciousness. Anaphylaxis usually occurs within minutes of exposure, but can be delayed for as long as four hours. Treatment involves an immediate dose of epinephrine, which should be carried at all times by people with a history of severe or anaphylactic allergic reactions.

2. What causes allergies?

The most common causes of allergies are pollen and dust mites. Pollen is an outdoor airborne allergen that causes seasonal allergies, or hay fever. Dust mites are tiny creatures that live on bedding, couches, and rugs. Other common causes include pet dander (cats > dogs), mold and mildew, cigarette smoke, and cockroaches. If you have a family member with allergies, you are more likely to develop allergies as well.

3. How are allergies diagnosed?

If you experience allergic symptoms lasting longer than a week or two, or which cause difficulties in your daily life, you may benefit from evaluation and management by your doctor.

Most often, allergies are diagnosed based on symptoms. If further testing is necessary, skin testing can be done. This involves pricking your skin with a variety of different allergens and seeing if your immune system reacts by causing a red, itchy bump on your skin like a mosquito bite. A blood test is also available.

Neither of these tests is perfect, and your doctor will use the results in combination with your symptoms to help you find the best options for treatment.

4. What can I do to avoid allergies?

For seasonal allergies, keep in mind that peak pollen season is from August to November and that pollen amounts are highest from 5 a.m. to 10 a.m. Try to plan outdoor activities for the afternoon. Changing your clothes and taking a shower after being outdoors can also help.

For dust mites, wash all bedding once a week in hot water. Buy bedding with synthetic materials instead of wool or feathers, and use dust-proof covers on your mattresses and pillows. Vacuum twice a week and wear a mask and gloves when cleaning.

For mold and mildew, try to keep the humidity in your home lower than 50% by using a dehumidifier. Avoid having indoor plants, as wet soil encourages mold growth. Don’t leave wet clothes in the washer and don’t leave wet towels lying around.

For pet dander, keep your pet outdoors as much as possible. If you must keep your pets indoors, do not allow them in the bedroom, wash hands frequently after handling pets and bathe them at least weekly. Cat dander can stay airborne for up to 24 hours.

5. What treatments are available?

Treatment depends on your symptoms. Keep in mind that often the symptoms of allergies can only be controlled, not cured.

Medications — there are a number of medications which can help decrease allergy symptoms. Some medications are available over the counter, while others require a prescription. Antihistamines stop your immune system from reacting to the allergen and causing symptoms. Some examples are oral antihistamines; antihistamine nose sprays; and antihistamine eye drops. Decongestants help to reduce swelling of blood vessels and tissues. Steroids reduce overall inflammation. Examples include steroid prescription nasal sprays.

Other medications used for allergies include leukotriene inhibitors and anti-inflammatory eye drops.

Speak with your doctor about which medications are right for you.

When lifestyle changes and medications aren’t enough, allergy shots or immunotherapy are an option. Allergy shots are injections of small amounts of the specific allergen that you are allergic to. Over time, these shots can “train” your body not to respond so strongly to the allergen.

These shots are managed by an Allergist and are given on a schedule; usually you will start with 2-3 shots a week and can space these out over 3-5 years.

For more information, visit  http://my.clevelandclinic.org/health/diseases_conditions/hic_Allergy_Overview (Multiple sections on allergies; probably the best single resource), http://www.allergyexpert.us/environmental/environmentalallergies.html or http://kidshealth.org/teen/diseases_conditions/allergies_immune/allergies.html#.

This column is for general information, and any specific questions or concerns regarding this topic should be brought to your physician.