Anaphylaxis is a severe allergic reaction that can cause symptoms such as swelling, hives, and nausea. Prompt treatment with an epinephrine auto-injector can help prevent complications.

While most allergies are not serious and are manageable with standard medication, some allergic reactions can lead to life threatening complications. One of these complications is called anaphylaxis.

Anaphylaxis is a severe, whole-body reaction that typically involves your heart and circulatory system, lungs, skin, and digestive tract. It can also affect your eyes and nervous system.

A severe allergy attack may be caused by consuming a food allergen, such as peanuts, milk, wheat, or eggs. It may also arise due to insect stings or certain medications.

Immediate medical attention is needed to prevent this severe allergic reaction from worsening.

If you have severe allergies, you most likely carry a medication called epinephrine. It comes in the form of an easy-to-use auto-injector that allows you or someone else to inject the medication into a muscle.

Epinephrine works quickly to raise your blood pressure, stimulate your heart, decrease swelling, and improve your breathing. It is the preferred treatment for anaphylaxis.

Self-help

If you’re experiencing anaphylaxis and can use an auto-injector yourself, inject a dose of epinephrine right away. For the best results, inject it into your thigh.

Talk with your doctor about the timing of your injection. Some experts advise using epinephrine as soon as you realize you’ve been exposed to an allergen, while others do not recommend using it until you have symptoms.

After using epinephrine, you should go to the emergency room in case you need any follow-up care. At the hospital, you might receive oxygen, antihistamines, and intravenous (IV) corticosteroids — typically methylprednisolone.

You might need to stay at a the hospital for at least a few hours so healthcare professionals can monitor your treatment and watch for any further reactions.

First aid for others

If you think someone is experiencing anaphylaxis, take these immediate steps:

  1. Ask another person to call for medical help. If no one else is nearby, call 911 or your local emergency services.
  2. Ask the person whether they carry an epinephrine auto-injector. If so, help them inject the medication according to the directions on the label. Don’t give epinephrine to someone who hasn’t been prescribed the medication.
  3. Help the person stay calm and lie down quietly with their legs elevated. If they vomit, turn them onto their side to prevent choking. Don’t give them anything to drink.
  4. If the person loses consciousness and stops breathing, begin CPR and continue until medical help arrives. You can follow these instructions for performing CPR.

Importance of medical treatment

It’s important to get medical treatment for a severe allergy attack, even if the person begins to recover.

In many cases, symptoms can improve at first but then worsen quickly after a period of time. Medical care is necessary to prevent a recurrence of the attack.

The onset of anaphylaxis is relatively quick. You might experience a reaction within seconds of exposure to a substance that you’re allergic to. At this point, your blood pressure will decrease rapidly and your airways will constrict.

Anaphylaxis is caused by allergies — but not everyone who has allergies will experience this severe reaction.

Many people have experienced symptoms of an allergy, which may include:

Allergens that can cause your immune system to overreact include:

When you come into contact with a substance you’re allergic to, your body assumes it’s a foreign invader, and your immune system releases substances to fight it off. These substances cause other cells to release chemicals, leading to an allergic reaction and changes throughout your body.

In children

According to the European Centre for Allergy Research Foundation, the most common causes of anaphylaxis in children are food allergies. Common food allergens include:

Children are especially vulnerable to food allergies when they’re away from home. It’s important that you let all caregivers know about your child’s food allergies.

Additionally, teach your child never to eat homemade baked goods or any other foods that might contain unknown ingredients.

In adults

In adults, the most common causes of anaphylaxis are foods, medications, and venom from insect bites.

You may be at risk for anaphylaxis if you’re allergic to any medications, such as aspirin, penicillin, or other antibiotics.

“Anaphylaxis” is a broad term for a type of severe allergic reaction. However, anaphylaxis can be broken down into subtypes according to how the symptoms and reactions occur.

Uniphasic reaction

This is the most common type of anaphylaxis. The onset of the reaction is rather quick, with symptoms peaking 30 to 60 minutes after exposure to an allergen. Most cases of anaphylaxis are uniphasic.

Biphasic reaction

A biphasic reaction involves another instance of anaphylaxis that occurs after the initial attack, generally within 72 hours. Symptoms of the second reaction typically peak within 8 to 11 hours after the first reaction. Up to 20% of anaphylactic reactions may be biphasic.

Protracted reaction

This is the longest-lasting type of anaphylactic reaction. When a protracted reaction occurs, the symptoms of anaphylaxis persist and are difficult to treat, sometimes lasting as long as several weeks without resolving completely.

Protracted reactions are typically very uncommon. Persistent low blood pressure may occur, and extended hospitalization may be necessary.

Without treatment, anaphylaxis can lead to anaphylactic shock. This is a dangerous condition in which your blood pressure drops and your airways narrow and swell, limiting your ability to breathe. Your heart can also stop as a result of inadequate blood flow.

In the most severe cases, anaphylaxis can cause death. Prompt treatment with epinephrine can prevent the life threatening effects of anaphylaxis.

The outlook for anaphylaxis is positive when treatment measures are taken immediately. Timing is the key — without prompt treatment, anaphylaxis can be fatal.

If you have severe allergies, you need to keep an epinephrine auto-injector on hand at all times in case of exposure and anaphylaxis. Regular visits with an allergist can also help you manage your allergies.

Avoid known allergens whenever possible. If you suspect that you might be sensitive to any previously undiagnosed allergens, follow up with your allergist or primary care doctor.

Anaphylaxis a serious allergic reaction that requires immediate treatment. The symptoms of anaphylaxis include hives, swelling, nausea, and difficulty breathing.

If you have severe allergies, you should carry epinephrine with you and administer it at the first sign of an allergic reaction. Your symptoms may subside after epinephrine treatment, but they could return, so it’s important to go to the hospital for follow-up care.