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What is anaphylaxis? Anaphylaxis is a life-threatening allergic reaction that usually happens without warning. It is a medical emergency and must be treated immediately. Your risk for anaphylaxis increases if you have asthma that is severe or not controlled. Medical conditions such as heart disease can also increase your risk. It is important to be prepared if you are at risk for anaphylaxis. Your symptoms can be worse each time you are exposed to the trigger.

What may trigger anaphylaxis? An allergy to foods, medicines, and insect stings can trigger anaphylaxis. Some of the most common allergy triggers include:

  • Milk, peanuts, tree nuts, eggs, shellfish, wheat, and soy

  • Stings from bees, wasps, or fire ants

  • Antibiotics, NSAIDs, or aspirin

  • Latex found in medical gloves

What are the signs and symptoms of anaphylaxis? Symptoms may develop within seconds to hours after exposure to a trigger. You may have any of the following symptoms:

  • Trouble breathing, shortness of breath, wheezing, or coughing

  • Throat tightening, swelling of the lips or tongue, or trouble swallowing

  • Skin rash, hives, swelling, or itching

  • Nausea, vomiting, diarrhea, or abdominal cramps

  • Dizziness, lightheadedness, fainting, or confusion

  • Sudden behavior changes or irritability

How is anaphylaxis diagnosed? Your healthcare provider will examine you for signs of anaphylaxis. He will ask if you have a history of allergies. He will also ask about exposure to possible triggers and when they occurred. Tell your healthcare provider if you take medicines or have any health conditions.

How is anaphylaxis treated?

  • Epinephrine can relieve life-threatening signs and symptoms, such as swelling in your throat that blocks your ability to breathe. It is given by immediate injection or IV.

  • Medicines , such as antihistamines, steroids, and bronchodilators, can decrease inflammation, open airways, and make breathing easier. These medicines may be taken as a pill or inhaled.

  • Oxygen may be needed if your blood oxygen level is lower than it should be. You may get oxygen through a mask placed over your nose and mouth or through small tubes placed in your nostrils.

How can I be prepared if I am at risk for anaphylaxis?

  • Carry epinephrine with you at all times. If you think you have been exposed to a trigger and have symptoms of anaphylaxis, call 911. Inject epinephrine. Then lie down on your back with your feet raised. Ask your healthcare provider if you need to carry other medicines.

  • Identify and avoid known triggers. Read food labels for ingredients. Look for triggers in your environment.

  • Create an anaphylaxis emergency action plan with your healthcare provider. The emergency action plan lists the signs and symptoms of anaphylaxis. It also gives directions for what to do in case of anaphylaxis. Give this plan to family, coworkers, and care providers.

  • Wear medical alert jewelry or carry a card that lists your allergies. Ask your healthcare provider where you can get these items.

  • Ask about treatments to help prevent anaphylaxis , such as allergy shots.

When should I contact my healthcare provider?

  • You have questions or concerns about your condition or care.

When should I seek immediate care or call 911?

  • You have any of the following signs and symptoms of anaphylaxis:

    • A skin rash, hives, swelling, or itching

    • Trouble breathing, shortness of breath, wheezing, or coughing

    • Throat tightening or swelling of your lips or tongue

    • Trouble swallowing or speaking

    • Dizziness, lightheadedness, fainting, or confusion

    • Nausea, vomiting, diarrhea, or abdominal cramps

  • You have taken medicine for anaphylaxis and your symptoms return.


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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