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Your Go-To Guide for Understanding and Treating Allergic Reactions

Keeping your family safe and healthy is important. But what happens when something as common as a snack or a pet can trigger a potentially dangerous reaction.

Allergic reactions can be scary. However, with some knowledge and planning, you can handle and even prevent these life-threatening reactions.

We talked to Tara Carr, MD, an allergist and immunologist with Banner – University Medicine, to find out more about allergic reactions, how to recognize them and most importantly, how to keep you and your family safe.

What are allergic reactions?

“When you have an allergic reaction, it’s because your body’s defense system, called the immune system, reacts strongly to something it doesn’t like,” Dr. Carr said. “This reaction involves special cells in your body, like mast cells and basophils, releasing a substance called histamine.”

Usually, the immune system stands guard and defends against intruders that can be dangerous to our health, such as viruses and bacteria. Sometimes, this system overreacts by detecting harmless substances as threatening. 

A person with no allergy may not have a reaction. An allergic person’s immune system goes into overdrive, releasing histamines that cause symptoms.

The most common food allergies include peanuts and tree nuts, soy, cow’s milk, eggs, wheat, fish and shellfish. The most common environmental allergens are pollens from trees, grasses and weeds, insect stings and bites from bees, wasps and fire ants, animal dander, dust, dust mites and mold. 

Other allergy triggers may include latex and medication allergies (or drug reactions). “The most common medication allergies are penicillin and non-steroidal anti-inflammatories (NSAIDs) like ibuprofen and aspirin,” Dr. Carr said.

What are the symptoms of an allergic reaction?

Symptoms of an allergic reaction can range from mild to moderate to severe (anaphylactic)

Mild allergic reactions do not require medical assistance. Moderate reactions need medical assistance but not urgently, while severe anaphylactic reactions are a medical emergency. 

Here are the key differences between the three:

  • Mild symptoms may include hay fever that causes sneezing, a runny nose, itchy, watery eyes and sometimes a rash. 
  • Moderate reactions cause breathing problems, like wheezing and difficulty swallowing. 
  • Symptoms of anaphylaxis or severe allergic reactions cause a sharp drop in blood pressure, cardiac arrest and shock. 

How do you treat allergic reactions?

“Each person who has an allergy is going to be a little bit different in terms of what they’re allergic to and how their symptoms bother them,” Dr. Carr said. “The decision on what kind of treatment to use for which symptoms and at what severity really needs to be part of a decision with their health care provider.”

Treating mild to moderate allergic reactions

Generally, mild allergic reactions can be treated with over-the-counter antihistamines like diphenhydramine (Benadryl) and cetirizine (Zyrtec) to relieve symptoms such as itching and hives

“Some antihistamines like Zyrtec and Benadryl need only a few minutes to provide fast relief for allergy symptoms,” Dr. Carr said.

It’s important to keep these medications on hand and follow the dosage instructions.

Treating severe allergic reactions

Prompt action is essential in the case of severe allergic reactions, known as anaphylaxis. 

“More severe reactions should be treated with epinephrine (EpiPen), which is the best and fastest way to stop and reverse an allergic reaction,” Dr. Carr said. “If someone uses an EpiPen, they should then be checked in an emergency room to ensure the reaction has completely resolved and that there are no other consequences that need to be addressed.”

[Do you need an EpiPen? Find out how and when to use a lifesaving EpiPen.]

Should I create an allergy action plan? How do I put one together?

Prevention is key when it comes to managing allergies. Work together with your allergist or health care provider to create an allergy action plan.

An allergy action plan is a written document that outlines what to do in case of an allergic reaction, including when to administer medication, which medications for which symptoms and when to seek emergency medical care (call 911).

“For example, give 25 milligrams of Benadryl by mouth for hives on the skin,” Dr. Carr noted. “Give epinephrine 0.3 intramuscularly for coughing, wheezing, vomiting or lightheadedness.”

The most important thing for allergies is avoidance, so if certain foods or medications must be avoided at school or work, everybody needs to know so they can help prevent problems. 

“Providing an action plan will allow them to treat a reaction right away, which is super important because the sooner you treat a reaction, the more likely someone recovers quickly,” Dr. Carr said.

What else can I do to help prevent reactions?

In addition to creating an allergy action plan, there are several other steps you can take to try and prevent allergic reactions:

  • For food allergies: Read all food labels and communicate your dietary needs to restaurants, family members, friends, caregivers and school staff. A medical alert bracelet can also be very helpful. Consider packing safe snacks and meals when traveling or attending events where food may be served.
  • For pet allergies: Avoid the animal or have environmental measures to reduce exposure, such as air filters.
  • For outdoor allergies: Monitor pollen levels and stay indoors on high pollen days, especially during peak allergy seasons. Wash your hands and change clothes after spending time outdoors to remove pollen and other outdoor allergens.
  • Keep a safe home: Keep your home environment as allergen-free as possible. Regularly clean surfaces, vacuum carpets and rugs, wash bedding in hot water and use allergen-proof covers on pillows. Avoid foods that contain allergens in your home. Consider keeping pets out of certain areas of the house, such as bedrooms, and regularly groom and bathe them to reduce dander.
  • Allergy testing and immunotherapy: In some cases, allergy testing and allergen immunotherapy (such as allergy shots or sublingual immunotherapy) may be recommended by your health care provider to help reduce allergic reactions over time. 


Navigating the world of allergies can feel overwhelming. But with some knowledge, preparation and a solid plan in place, you can effectively manage and even prevent allergic reactions.

Don’t hesitate to contact your health care provider or a Banner Health specialist for guidance and support in managing your allergies. Knowledge and preparedness are key to managing allergic reactions effectively and living a healthy, allergy-aware lifestyle. 

For more allergy tips, check out:

Allergy and Immunology Safety