1. What is an allergy?
2. What causes allergies?
3. Do children outgrow allergies?
4. Should I move away to escape the hay fever season?
5. Are allergies inherited?
6. Can breast-feeding prevent allergies?
7. What is an anaphylactic reaction?
8. Are some animals more likely to cause allergic reactions than others?
9. How are allergies diagnosed?
10. What is the most effective allergy treatment?

1. What is an allergy?

An allergy is an exaggerated physical response to an ordinarily harmless substance such as pollen, certain foods or drugs, or to insect stings.

2. What causes allergies?

Allergies result from a "misfiring" of the immune system, which normally helps the body to fight off harmful viruses, bacteria and other microorganisms. In an allergic reaction, the immune system perceives pollen, food or other allergens as a threat to health. The immune system mobilizes against the "invaders" by creating antibodies that set off symptoms every time the allergenic substance enters your body or touches your skin, in the case of a contact allergic reaction.

3. Do children outgrow allergies?

Sometimes. Food allergies are most likely to be outgrown, and are more common in children than in adults. If children do outgrow allergies, it is often by age 3.

4. Should I move to another part of the country to escape the hay fever season?

Probably not. You may escape your current hay fever symptoms by moving to another area, but you could develop an allergy to a plant native to your new surroundings. Moving is not a practical solution to a pollen allergy.

5. Are allergies inherited?

Yes. If one of your parents has a respiratory allergy, you have a 30 to 50 percent chance of developing one, though not necessarily the same allergy. If both your parents have respiratory allergies, there's a 60 to 80 percent likelihood that you will also develop an allergy.

6. Can breast-feeding prevent allergies?

There's no proof that breast-feeding protects the children of allergic parents from developing allergies later in life, but it could delay the onset of allergies. Delaying the introduction of solid foods can further prolong the allergy-free period in babies who inherit a tendency toward allergy.

7. What is an anaphylactic reaction?

Anaphylaxis is a severe, life-threatening allergic reaction – usually to foods, drugs or insect venom. The reaction can cause dizziness, breathing problems, an asthma attack, hives, a sudden drop in blood pressure or unconsciousness. If not treated promptly and correctly, an anaphylactic reaction can be fatal. People subject to these reactions should carry an emergency kit containing the drug epinephrine for use at the first sign of symptoms.

8. Are some animals more likely to cause allergic reactions than others?

Yes. Cats are more likely than dogs to trigger an allergic response. An allergen attaches to animal hair or dander (shed skin) when the pet grooms itself. Loosened hair can become airborne and stick to walls and clothing.

9. How are allergies diagnosed?

Your doctor may be able to diagnose an allergy on the basis of your symptoms and exposure to allergens. For instance, if you have allergy symptoms only during ragweed season, you probably are allergic to ragweed. If you have year-round symptoms, the problem could be dust mites, pet allergies, or an allergy to a substance you come into contact with at work. You may also need some tests to identify the allergen. The simplest and most reliable is a skin test that scratches a drop of allergen extract into your skin. If you are allergic to the substance, a reaction will develop within 15 minutes. A less accurate and more expensive blood test can be used when skin tests aren't practical (if you have eczema or a skin condition that doesn't permit testing) or would be dangerous (if you are severely allergic).

10. What is the most effective allergy treatment?

Avoiding the substance that causes your allergy. This isn't always possible if you have an allergy to pollen or dust mites, but you usually can reduce your exposure.

Last updated December 03, 1996

1996-1999 The Johns Hopkins University. All rights reserved. Source: Inteli-Health Inc. All information is intended for your general knowledge only and is not a substitute for medical advice or treatment for specific medical conditions. You should seek prompt medical care for any specific health issues and consult your physician before starting a fitness regimen. Use of this online service is subject to InteliHealth's disclaimer and the terms and conditions.