There are few things more frightening than having or witnessing an anaphylactic reaction. The symptoms can go from bad to worse very quickly, and may include:

  • trouble breathing
  • hives
  • swelling of the face
  • vomiting
  • fast heartbeat
  • fainting

If you witness someone having anaphylactic symptoms, or you’re having symptoms yourself, call emergency services immediately.

If you’ve had a severe allergic reaction in the past, your doctor may have prescribed an emergency epinephrine injection. Getting a shot of emergency epinephrine as quickly as possible can save your life — but what happens after the epinephrine?

Ideally, your symptoms will begin to improve. Sometimes they can even resolve completely. This may lead you to believe that you’re no longer in any danger. However, this isn’t the case.

A trip to the emergency room (ER) is still required, no matter how well you feel after your anaphylactic reaction.

Epinephrine usually relieves the most dangerous symptoms of anaphylaxis quickly — including throat swelling, trouble breathing, and low blood pressure.

It’s the treatment of choice for anyone experiencing anaphylaxis. But you need to administer epinephrine in the first few minutes after the allergic reaction starts for it to be most effective.

Keep in mind that you should only give epinephrine to a person who’s been prescribed the medication. You should also follow the instructions carefully. Dosages vary, and individual medical conditions can affect how a person reacts to it.

For example, epinephrine could cause a heart attack in someone with heart disease. This is because it speeds up the heart rate and raises blood pressure.

Give an epinephrine injection if someone has been exposed to an allergic trigger and:

  • has trouble breathing
  • has swelling or tightness in the throat
  • feels dizzy

Also give an injection to children who has been exposed to allergic trigger and:

  • have passed out
  • vomit repeatedly after eating a food they’re severely allergic to
  • are coughing a lot and having trouble catching their breath
  • have swelling in the face and lips
  • have eaten a food they’re known to be allergic to

Before using the auto-injector, read the instructions. Each device is a little bit different.


When you receive your epinephrine auto-injector prescription from the pharmacy, BEFORE you need it, examine it for any deformity. Specifically, look at the carrying case and be sure it is not warped and the auto-injector will slide out easily. Also, examine the safety cap (usually blue) and be sure it is not raised. It should be flush with the sides of the auto-injector. If any of your auto-injectors do not slide out of the case easily or have a safety cap that is slightly raised, take it back to the pharmacy for a replacement. These deformities can cause a delay in administering the medication, and any delay in an anaphylactic reaction can be life threatening. So again, BEFORE you need it, please examine the auto-injector and make sure there are no deformities.

In general, to give an epinephrine injection, follow the steps below:

  1. Slide the auto-injector out of the carrying case.
  2. Prior to use, the safety top (usually blue) must be removed. To do this properly, hold the body of the auto-injector in your dominant hand and with your other hand pull off the safety cap straight up with your other hand. DO NOT try to hold the pen in one hand and flip the cap off with the thumb of the same hand.
  3. Hold the injector in your fist with the orange tip pointing down, and your arm at your side.
  4. Swing your arm out to your side (like you’re making a snow angel) then quickly down to your side so that the tip of the auto-injector goes directly into your thigh on the side with some force.
  5. Keep it there and press down and hold for 3 seconds.
  6. Remove the auto-injector from your thigh.
  7. Place the auto-injector back into its case, and GO IMMEDIATELY to the emergency department of the nearest hospital for review by a doctor and disposal of your auto-injector.

After you give the injection, call 911 or your local emergency services if you haven’t already done so. Tell the dispatcher about the anaphylactic reaction.

While you wait for medical help to arrive, take these steps to keep yourself or the person who’s having the reaction safe:

  • Remove the source of the allergy. For example, if a bee sting caused the reaction, remove the stinger using a credit card or tweezers.
  • If the person feels like they’re about to faint or they’re fainting, lay the person flat on their back and raise their legs so that blood can get to their brain. You can cover them with a blanket to keep them warm.
  • If they’re throwing up or having trouble breathing, especially if they are pregnant, sit them up and even a little forward if possible, or lay them on their side.
  • If the person becomes unconscious, lay them down with their head tilted back so that their airway isn’t closed off and check for pulse. If there is no pulse and the person is not breathing, give two quick breaths and start CPR chest compressions.
  • Give other medications, such as an antihistamine or an inhaler, if they’re wheezing.
  • If symptoms don’t improve, give the person another injection of epinephrine. Doses should occur 5 to 15 minutes apart.

An injection of emergency epinephrine could save a person’s life after an anaphylactic reaction. However, the injection is only one part of the treatment.

Everyone who’s had an anaphylactic reaction needs to be examined and monitored in an emergency room. This is because anaphylaxis isn’t always a single reaction. The symptoms can rebound, returning hours or even days after you get an epinephrine injection.

Most cases of anaphylaxis happen quickly and fully resolve after they’re treated. However, sometimes the symptoms get better and then start again a few hours later. Sometimes they don’t improve hours or days later.

Anaphylactic reactions happen in three different patterns:

  • Uniphasic reaction. This type of reaction is the most common. Symptoms peak within 30 minutes to an hour after you’re exposed to the allergen. Symptoms get better within an hour, with or without treatment, and they don’t return.
  • Biphasic reaction. Biphasic reactions occur when symptoms go away for an hour or more, but then return without your being reexposed to the allergen.
  • Protracted anaphylaxis. This type of anaphylaxis is relatively rare. The reaction can last for hours or even days without completely resolving.

Recommendations from the Joint Task Force (JTF) on Practice Parameters advise that people who’ve had an anaphylactic reaction be monitored in an ER for 4 to 8 hours afterward.

The task force also recommends that they be sent home with a prescription for an epinephrine auto-injector — and an action plan on how and when to administer it — due to the possibility of a recurrence.

The risk of a rebound anaphylactic reaction makes proper medical evaluation and aftercare crucial, even for people who feel fine after treatment with epinephrine.

When you go to the emergency department to be treated for anaphylaxis, the doctor will do a full examination. The medical staff will check your breathing and give you oxygen if needed.

If you continue to wheeze and have trouble breathing, you may be given other medications by mouth, intravenously, or with an inhaler to help you breathe more easily.

These medications can include:

You’ll also get more epinephrine if you need it. You’ll be carefully observed and given immediate medical attention if your symptoms come back or get worse.

People with very severe reactions may need a breathing tube or surgery to open their airways. Those who don’t respond to epinephrine might need to get this drug through a vein.

Once you’ve been successfully treated for an anaphylactic reaction, your goal should be to avoid another one. The best way to do that is to stay away from your allergy trigger.

If you’re not sure what caused your reaction, see an allergist for a skin prick or blood test to identify your trigger.

If you’re allergic to a certain food, read product labels to make sure you don’t eat anything containing it. When you eat out, let the server know about your allergies.

If you’re allergic to insects, wear an insect repellant whenever you go outdoors in the summer and stay well covered with long sleeves and long pants. Consider lightweight clothing options for the outdoors that keep you covered but cool.

Never swat at bees, wasps, or hornets. This may cause them to sting you. Instead, slowly move away from them.

If you’re allergic to medication, tell every doctor that you visit about your allergy, so they don’t prescribe that drug for you. Also let your pharmacist know. Consider wearing a medical alert bracelet to let emergency responders know that you have a drug allergy.

Always carry an epinephrine auto-injector with you, in case you do encounter your allergy trigger in the future. If you haven’t used it in a while, check the date to make sure that it hasn’t expired.