How to Use an EpiPen: Anaphylaxis Emergency Instructions

Whether you’re managing a known allergy or trying to keep a loved one safe, facing a severe allergic reaction can bring up a lot of questions. Adrian G. Letz, MD, UnityPoint Clinic Allergist Immunologist, breaks down the signs of anaphylaxis, how to use an epinephrine auto-injector (EpiPen) and what to do in an emergency.

What Exactly is Anaphylaxis?

Anaphylaxis is the medical term for the most severe, systemic kind of allergic reaction. Because it's systemic, multiple body systems are involved at the same time, making it potentially life-threatening.

While a mild allergy might cause a little discomfort, severe anaphylaxis symptoms come on quickly and need immediate medical attention. Common signs of anaphylaxis include:

• Itching, flushing, hives and swelling of the skin
• Low blood pressure, which can cause dizziness or even passing out
• Throat tightness, trouble breathing, coughing or wheezing
• Metallic taste in the mouth
• Impending sense of doom

“A lot of people don’t know they can have GI symptoms with anaphylaxis,” Dr. Letz says.f “You could have vomiting, acute diarrhea, abdominal pain and women can even have uterine cramps.”

You don’t have to experience every single one of these symptoms to be in danger. If you have a known allergy and start experiencing a reaction, you need to use your emergency medication right away.

Are There Different Types of Anaphylaxis?

Yes. While most reactions are triggered by an exposure you can pinpoint, there are a few specific variations of anaphylaxis:

• Idiopathic anaphylaxis: This is a clinical diagnosis given when a severe reaction occurs for completely unknown reasons, pointing to a genetic cause that’s not fully understood yet.
• Exercise-induced anaphylaxis: A rare form of severe reaction triggered directly by physical exertion.
• Food-induced exercise-induced anaphylaxis: This is where, on separate occasions, you can eat food and exercise and feel fine. “But if you eat that food about an hour before exercise, then you get anaphylaxis,” Dr. Letz says. Common culprits include wheat, peanuts, tree nuts, shellfish, milk, eggs or even celery. If you’re diagnosed with this type of anaphylaxis, exercise with a buddy, carry a cell phone and always have your medication on hand.

What Kind of Allergies Require an EpiPen?

An EpiPen is prescribed for individuals with a high risk of systemic reactions. The most common triggers include:

• Bee sting allergy & wasp sting allergy: Dr. Letz says the "stinging insect” aspect of the allergy is important, because common pests like mosquitoes don’t cause anaphylaxis.
• Drug allergy: A severe medication allergy, most commonly to antibiotics (like a penicillin allergy) or NSAIDs (like ibuprofen).
• Latex allergy: Severe reactions to natural rubber latex products.
• Peanut allergy & tree nut allergy: Along with a shellfish allergy, milk allergy or egg allergy, these are the most common food triggers.

What is an EpiPen and What Does It Do? 

An EpiPen is simply a well-known brand name for an epinephrine auto-injector. Other options include brand names like Auvi-Q as well as generic epinephrine auto-injectors.

What Does an EpiPen Do?

An EpiPen delivers a calculated dose of epinephrine, which is another word for adrenaline — a hormone naturally produced by your body's adrenal glands. During a severe reaction, it works within minutes to turn the reaction around by:

• Constricting blood vessels to pull your blood pressure back up
• Increasing your heart rate to improve cardiac output
• Opening up your airways in the lungs, which is incredibly vital if you also manage asthma
• Stabilizing your mast cells to halt the ongoing flood of allergic chemicals into your body

EpiPen Dose Guidelines 

The standard epinephrine dose for anaphylaxis is based on weight:

• Epinephrine dose for anaphylaxis in adults: 0.3 milligrams of epinephrine, used for anyone weighing over 67 pounds (30 kilograms)
• Pediatric Dose (EpiPen Jr): 0.15 milligrams of epinephrine, designed for children weighing under 67 pounds

When and How to Use an EpiPen

Knowing when to use an EpiPen can save a life. If you accidentally ingest a food allergen or get stung by a bee but feel completely fine with no symptoms, you don't need to inject right away. There’s only a 50% chance of a severe reaction happening with any given sting. However, the moment systemic anaphylaxis symptoms show up, use the device immediately.

“Early use of epinephrine has been shown to be life-saving,” Dr. Letz says. “A risk factor for death from anaphylaxis is the late use of epinephrine.”

Can You Use an EpiPen for Hives? 

No. While diffuse hives can look alarming and feel bothersome, everyday hives alone don’t progress to anaphylaxis. Hives should be treated with antihistamines rather than epinephrine.

What Happens if I Use an EpiPen and Don't Need It? 

If you administer it out of caution and it turns out you didn't need it, you’ll likely just feel jittery, amped up or notice your heart racing.

“Intramuscular epinephrine is very well-tolerated,” Dr. Letz says. “Serious adverse reactions from it are very rare.”

These minor side effects typically wear off safely within about half an hour.

How to Administer an EpiPen

When an emergency strikes, follow these simple steps for anaphylaxis treatment:

1. Prepare: Remove the auto-injector from its carrier tube and pull off the safety release cap.
2. Placement: Swing and push the orange tip firmly against the outer thigh (lateral thigh). The EpiPen needle is contained inside the auto-injector and will deploy into the muscle upon contact. The thigh is chosen because it’s a large, highly vascular muscle area that absorbs the medicine rapidly.
3. Hold: Hold it firmly in place for the duration recommended on your specific device package to ensure the full epi dose for anaphylaxis is delivered.
   Always carry two EpiPens with you. While one dose successfully resolves the reaction about 80% of the time, you may need to administer the second dose if your symptoms are still ongoing 10 minutes later.

An oral antihistamine can be used as a secondary support tool, but they take up to an hour to absorb and don’t replace the immediate, life-saving effects of epinephrine.

What to Do After Using an EpiPen 

Go straight to the nearest emergency room. Epinephrine buys you critical time, but you must be evaluated by medical professionals to ensure the EpiPen allergic reaction is completely resolving, and your blood pressure remains stable and safe.

What About Expired EpiPens or Alternative Options? 

Keep your EpiPen fully up-to-date. However, if your EpiPen has expired, Dr. Letz says, “As long as the fluid is clear, it’s probably going to be more useful than doing nothing.”

If you're looking for an EpiPen alternative — such as a different brand like Auvi-Q or a generic epinephrine auto-injector — or if you've experienced a severe reaction in the past, schedule an allergy consultation.

“Any patients who've experienced anaphylaxis should have an allergy consultation,” Dr. Letz says.

An allergist or primary care provider can evaluate your history, review your current prescriptions and make sure you have a treatment plan in place.

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