Anaphylaxis is an allergic reaction that affects the entire body and is considered a medical emergency. This potentially life-threatening reaction can happen anywhere between seconds to minutes after exposure to the allergen. Exposure triggers a response from your immune system that can lead to shock and even death if it is not treated immediately.

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Break It Down: Anaphylaxis (Video Transcript)

Anaphylaxis, which is sometimes called anaphylactic shock, is a severe allergic reaction. The reaction can be to certain foods like nuts, insect stings, medications, or anything to which a person is severely allergic. Allergic reactions present with a variety of symptoms, such as hives, abdominal pain, nausea and vomiting, and rapid swelling of the tongue and lips.

If not treated immediately, anaphylaxis can be deadly.


What happens is that your immune system mistakes a normally harmless substance, such as peanuts, for a dangerous foreign invader and mounts a full-scale immunologic response, which creates a host of complications. For instance, fluid can accumulate in your lungs, making it difficult to breathe. Blood vessels open wider, causing a drop in blood pressure. If this progresses, a person can go into shock.

Who is at Risk?

Most people with a severe allergy are diagnosed as children, usually after exposure to a food allergen. You should know that it’s possible to be severely allergic to something and not realize it until you suffer a reaction.

Signs and Symptoms

It’s critical to understand the signs and symptoms of anaphylaxis, so you can react quickly in the event of an emergency. The most common signs of a severe anaphylactic reaction include: trouble breathing, coughing wheezing, facial swelling, swelling in the mouth and throat, tchy skin, including hives, red skin rash, nausea, weakness or dizziness, low blood pressure, rapid or irregular heart rate, abdominal pain, anxiety, confusion and slurred speech

Treatment and Prevention

We are all exposed to foods, medications, plants, animals, cosmetics, and chemicals every day about which we are unaware, so allergic reactions will continue to happen and we need to be ready to treat them. The single most powerful therapy we have for treating anaphylactic shock is epinephrine. When it’s administered in a therapeutic dose, it usually quickly alleviates the most severe symptoms of anaphylaxis. Epinephrine is available in easy-to-use emergency auto-injectors.

If you or a loved one has been prescribed an epinephrine injector, there are a number of things you should be aware of:

  1. Instruct your family, close friends, your child’s teacher, and other people who might need to use the device on how to operate the emergency epinephrine injector.
  2. Emergency epinephrine is not a replacement for a doctor or an emergency department. If someone is suffering an anaphylactic reaction, they should immediately be given the shot of epinephrine and then be brought to the emergency department as quickly as possible for a full evaluation.
  3. Be prepared to need to administer a second injection. Even though the first injection may be effective in stopping the allergic response, it also may have only a limited period of effectiveness. Therefore, you many need to administer a second injection.
  4. Always check the expiration date on each epinephrine injector. Be certain that you’re carrying up-to-date medications.

Any substance you are severely allergic to can trigger anaphylaxis. The most common food culprits include nuts, shellfish, and eggs. Bee stings and other insect bites can cause anaphylaxis as well. Drug allergies are also common triggers; according to the World Allergy Organization, drugs may be responsible for as much as 20 percent of deaths from anaphylaxis worldwide.

Some less common triggers of anaphylaxis include exercise and latex.

Signs and Symptoms of Anaphylaxis

Anaphylaxis can cause a multitude of symptoms almost immediately after exposure to the trigger. The following are possible signs and symptoms of anaphylaxis:

  • chest tightness
  • trouble breathing or speaking
  • feeling of a lump in the throat
  • tongue swelling
  • wheezing or a high-pitched sound when breathing
  • coughing
  • feeling flushed or hot
  • difficulty swallowing (dysphagia)
  • facial swelling
  • hives or rash
  • changes in the color of the skin, such as pink and flushed, pale, or blue
  • gastrointestinal symptoms, such as diarrhea, nausea, or vomiting
  • unconsciousness
  • death

Along with the symptoms listed above, a person may also experience severe anxiety or a feeling of impending doom.

Knowing the signs and symptoms of anaphylaxis is crucial for anyone with a known severe allergy or those with a loved one with allergies. Avoiding the allergen is the only way to prevent the reaction. In some cases, however, the allergy is not yet known, making awareness of the signs and symptoms even more important. According to the American Academy of Allergy, Asthma and Immunology, up to 50 percent of people worldwide who die from a severe insect allergy had no documented history of a previous reaction.

Risk Factors

There are few known risk factors for anaphylaxis. It is believed that genetics may increase a person’s risk of this type of reaction. This is thought to be especially true for people with a family history of exercise-induced anaphylaxis.

People who suffer from allergies or asthma are also at an increased risk of anaphylaxis. If you have already experienced anaphylaxis, you are at high risk of it experiencing it again.

If you have a high risk of anaphylaxis, you can lower your risk of this type of severe allergic reaction by avoiding your known triggers. It’s also important that people at risk and their loved ones be prepared for possible emergency situations. Patients with severe allergies are generally advised to carry an epinephrine autoinjector at all times, and also ensure that both they and those close to them know how to properly use an autoinjector. An autoinjector is a device consisting of a concealed needle and syringe with one full dose of medication. When this is injected into the outer portion of the upper thigh, it can slow or stop the allergic reaction and potentially save a person’s life.