Understanding which food allergy symptoms may signal an emergency is crucial. In some situations, an over-the-counter (OTC) antihistamine can help ease mild symptoms. However, some symptoms of an allergic reaction are more serious and need emergency care, including an epinephrine auto-injector (Auvi-Q, EpiPen, EpiPen Jr) or epinephrine nasal spray (Neffy).

Here’s what you need to know about how food allergies are treated, how epinephrine auto-injectors and antihistamines like diphenhydramine (sold as Benadryl and other brands) fit into treatment, and how to make a treatment plan that works for you or your child.

Preparing for Food Allergy Reactions

Talk with your healthcare provider about how to prepare for unexpected allergic reactions. They can help you create an emergency care plan for yourself or your child. This plan usually lists:

• The foods you or your child is allergic to
• Symptoms to watch for
• Medicines to take
• Steps to follow in an emergency

The plan may also include contact information for doctors and emergency contacts. This ensures everyone knows what to do during an allergic reaction and can help you feel more prepared.

Allergic reactions can vary, even to the same food. A food that causes a mild reaction once can cause a serious reaction another time. That’s why allergists tend to avoid labeling a person’s food allergy as “mild” or “severe.” Each reaction is different. This makes it important to pay close attention to food allergy symptoms and know when they may indicate a serious reaction.

Allergic reactions can vary, even to the same food. A food that causes a mild reaction once can cause a serious reaction another time.

Using Epinephrine for Food Allergies

If you or your child has a food allergy, your doctor has likely advised you to carry a set of epinephrine auto-injectors — or have them accessible — at all times. It’s important to have two with you because some reactions may need a second dose.

You should use an EpiPen or another epinephrine auto-injector when you need very fast relief from serious symptoms. An epinephrine auto-injector can provide quick emergency relief from symptoms of anaphylaxis. In some cases, a second dose may be needed if severe symptoms continue for more than five minutes after the first dose.

An epinephrine auto-injector can provide quick emergency relief from anaphylaxis symptoms.

Signs of Anaphylaxis

Anaphylaxis — also known as an anaphylactic reaction — is a life-threatening allergic reaction that can cause severe symptoms and may lead to anaphylactic shock. Trouble breathing is one of the most common signs.

Other symptoms include:

• Difficulty breathing
• Sudden drop in blood pressure
• Dizziness
• Fainting
• Weak and rapid pulse
• Rash or hives
• Swollen tongue or lips
• Nausea, vomiting, or diarrhea

Anaphylaxis can start within minutes of being exposed to a food allergen. Most reactions occur within two hours.

After using epinephrine, you need to go to the emergency room because a second wave of symptoms — called a biphasic reaction — can occur. You’ll need to be monitored by staff in the emergency department so you can get medical help if you need it.

Don’t hesitate to use an epinephrine auto-injector if you have symptoms of anaphylaxis. Use it right away, and seek emergency care. Talk with your healthcare team if you need training on how to use an epinephrine injector.

Using Antihistamines for Food Allergies

Some mild symptoms of food allergies can be treated with oral OTC antihistamines such as diphenhydramine or cetirizine. Researchers and doctors often recommend using cetirizine or another second-generation antihistamine instead of diphenhydramine, which can cause significant drowsiness.

Some mild symptoms of food allergies can be treated with oral OTC antihistamines.

Your doctor may suggest a specific OTC antihistamine to use for mild allergic reactions. Antihistamines can generally help with mild symptoms such as:

• Itchy or runny nose or sneezing
• Itchy mouth with no swelling
• Mildly itchy skin or other skin symptoms, like a few hives
• Mild stomach discomfort or nausea

Mild symptoms don’t affect breathing or heart rate. Antihistamines also take longer to work than epinephrine because they must move through the digestive system. If you notice any signs of anaphylaxis, don’t wait for an antihistamine to work — use epinephrine right away.

These symptoms are considered mild only when they appear in one area of the body. Mild symptoms in more than one area may be an early sign of a serious allergic reaction and can progress to anaphylaxis. When symptoms occur in more than one part of your body, you need emergency treatment with an epinephrine injection.

Understanding Risk Factors for Anaphylaxis

People with food allergies who’ve had anaphylaxis before have a higher risk of another anaphylactic reaction. Other factors that may raise the risk of anaphylaxis include:

• Other types of allergies
• Heart disease
• Mastocytosis (a condition that causes high levels of certain white blood cells)
• Asthma
• Current or recent illness
• Recent strenuous exercise
• Stress
• Lack of sleep
• Certain hormonal situations
• Some recreational drugs and medications

Talk with your doctor about your risk factors for a serious allergic reaction. Understanding your risks can help you plan how to respond. In some cases, you may need an epinephrine injection right after being exposed to a food allergen, even before symptoms appear.

Discussing Your Food Allergy Plan With Your Doctor

The best way to prepare for an allergic reaction is to create an allergy plan with your doctor. An allergy plan gives clear instructions on how to respond to an allergic reaction and which medicines to use.

Your doctor can explain how your medical history and current health may affect the safest way to treat an allergic reaction for you or your child. Once you have an allergy plan, make sure it’s easy to access or carry with you.

By following your treatment plan and avoiding known triggers, you can help prevent allergic reactions. An allergic reaction can be confusing and stressful. A clear allergy plan can help you feel more confident about what to do if you or your child has a reaction. If you don’t have an allergy plan, talk with your doctor about making one.

Join the Conversation

On MyFoodAllergyTeam, people share their experiences with food allergies, get advice, and find support from others who understand.

What did your doctor tell you about when to use epinephrine versus diphenhydramine for food allergies? Let others know in the comments below.