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What are allergies?

Allergies are an immune system reaction to a substance called an allergen. Your immune system sees the allergen as harmful and attacks it.

What causes allergies?

You may have allergies at certain times of the year or all year. You can be exposed to allergens by breathing them in (airborne) or by absorbing them through your skin (contact). You also may be exposed when you are stung by an insect. The following are common allergies:

  • Seasonal airborne allergies: Seasonal allergies happen during certain times of the year. This is also called hay fever. Tree, weed, or grass pollen are examples of allergens that you breathe in.

  • Environmental airborne allergies: Examples of allergens you may breathe in year-round are dust, mold, and pet hair.

  • Contact allergies: A common contact allergen is latex, found in condoms and medical gloves. Latex allergies can be very serious.

  • Insect sting allergies: Bees, hornets, fire ants, or other insects may sting you and cause allergic reactions. Insect allergies can be very serious.

What increases my risk for allergies?

Allergic reactions can happen at any time, even if you have not had allergies before. You may develop an allergy after you have been exposed to an allergen more than once.

  • Family history: You may be more likely to have allergies if you have a family member with allergies.

  • History of other allergies: If you are allergic to one thing, you are more likely to become allergic to other things.

  • Medical conditions: Asthma and other lung conditions may increase your risk of an allergic reaction.

  • Age: Allergic reactions are more common in children and the elderly.

What are the signs and symptoms of mild allergies?

  • Sneezing and runny, itchy, or stuffy nose

  • Swollen, watery, or itchy eyes

  • Itchy skin, mouth, ears, or throat

  • Swelling, pain, or itch at the site of an insect sting

What are the signs and symptoms of severe allergies?

A severe allergic reaction is called anaphylaxis. Anaphylaxis is life-threatening. The signs and symptoms may happen very fast. Seek care immediately or call 911 if you have any of the following:

  • Severe trouble breathing and swallowing because of throat swelling

  • Severe itching, hives, or rash

  • Rapid heartbeat and breathing

  • Wheezing

  • Nausea, vomiting, or diarrhea

  • Dizziness or fainting

How are allergies diagnosed?

Your healthcare provider will ask about your signs and symptoms. He will ask what allergens you have been exposed to and if you have ever had other allergic reactions. He may look in your nose, ears, or throat. You may also have the following tests:

  • Blood tests: Your blood is tested for signs of a reaction to allergens.

  • Nasal tests: A sample of your nasal fluid is tested to find how your nasal passages react to allergens.

  • Skin tests: Skin tests can help your healthcare provider find out what you are allergic to. He may place a small amount of allergen on your arm or back then gently prick your skin with a needle. He watches how your skin reacts to the allergen.

How are allergies treated?

  • Medicines:

    • Epinephrine: This is a hormone that is used to slow a serious allergic reaction. Your healthcare provider can show you how to give this shot. If you have had a serious allergic reaction before, you may want to carry epinephrine with you at all times.

    • Antihistamines: These help decrease itching, sneezing, and swelling. You may take them as a pill or use drops in your nose or eyes.

    • Decongestants: These help your nose feel less stuffy.

    • Steroids: Healthcare providers may give you steroids as a pill, as a shot, or to inhale. Steroids decrease swelling and redness.

    • Topical treatments: You may be given medicine to put directly on your skin to help decrease itching or swelling. Cold cloths or ice may also help your skin feel better. You also may be given nasal sprays or eye drops.

  • Desensitization: This treatment gets your body used to allergens you cannot avoid. Your healthcare provider will give you a shot that contains a small amount of an allergen. He will watch you closely and treat any allergic reaction you have. He will give you more of the allergen a little at a time until your body gets used to it. Your reaction to the allergen may be less serious after this treatment. Your healthcare provider will tell you how long to get the shots.

How can I manage my allergies?

  • Use nasal rinses: Healthcare providers may suggest that you rinse your nasal passages with a saline solution. Daily rinsing may help clear your nose of allergens.

  • Do not smoke: Your allergy symptoms may decrease if you are not around smoke. If you smoke, it is never too late to quit. Ask your healthcare provider for information about how to stop if you need help quitting.

  • Carry medical alert identification: You may want to wear medical alert jewelry or carry a card that says you have an allergy. Ask your healthcare provider where to get medical alert identification.

How can I avoid allergens?

  • Seasonal allergies: Do not go outside when pollen counts are high. Your symptoms may be better if you go outside only in the morning or evening. Use your air conditioner, and change air filters often.

  • Dust, fur, or mold allergies: Dust and vacuum your home often. You may want to wear a mask when you vacuum. Keep pets in certain rooms, and bathe them often. Use a dehumidifier (machine that decreases moisture) to help prevent mold.

  • Latex allergies: Do not use products that contain latex. Use nonlatex gloves if you work in healthcare or in food preparation. Always tell healthcare providers you have a latex allergy.

  • Insect stings: Stay away from areas or activities that increase your risk for being stung. These include trash cans, gardening, and picnics. Do not wear bright clothing or strong scents when you will be outside.

What are the risks of allergies?

  • If you have had a mild reaction, you may have a more serious reaction if you are exposed to the allergen again. You may have an anaphylactic reaction, which can be life-threatening even if treated. Medicines used to treat allergies may keep you awake or make you nervous. They also may make you sleepy or make it hard to focus. Epinephrine may upset your stomach. Epinephrine may not stop your anaphylaxis. You may have a serious or life-threatening reaction during a skin test or desensitization.

  • You may have trouble sleeping because of your allergies. Dry or irritated nasal passages may cause a bloody nose. If you do not treat symptoms, you may have long-term damage to your lungs, nose, and ears. You may not be able to hear as well. You may also lose your sense of taste or smell.

When should I contact my healthcare provider?

Contact your healthcare provider if:

  • You have tingling in your hands or feet.

  • Your skin is red or flushed.

  • You have stomach pain, nausea, vomiting, or diarrhea.

When should I seek immediate care?

Seek care immediately or call 911 if:

  • You have trouble swallowing or your throat or tongue is swollen.

  • You are wheezing or having trouble breathing.

  • You feel dizzy or faint.

  • You have chest pain or your heart is fluttering.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© 2014 Truven Health Analytics Inc. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or Truven Health Analytics.

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