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How to Recognize and Treat Allergic Reactions

Sneezing, watery eyes and itchy skin. While some symptoms of allergies are mildly annoying, others can be extremely uncomfortable and even life-threatening. The causes for allergic reactions can vary person to person, so it’s important to understand and recognize the symptoms and know how to treat them.

To better understand allergic reactions, we spoke with William Culver, MD, who specializes in allergy and immunology at the Banner Health Clinic in Loveland, Colorado.

What Causes Allergic Reactions to Occur?

Normally, the immune system stands guard and defends our bodies against intruders that can be dangerous to our health, such as viruses and bacteria. When it detects foreign bodies, our immune system attacks the invaders by creating millions of antibodies—proteins that neutralize the threat.

“In some people, however, they make allergic antibodies to various, usually harmless, substances, such as airborne pollen, animals, foods and medications,” Dr. Culver said. “Upon re-exposure to these allergens, the allergic antibody interacts with cells throughout the body to cause a spectrum of reactions, ranging from mild to severe.”

What are the Most Common Allergens?

According to the American Academy of Allergy, Asthma and Immunology (AAAAI), approximately 50 million Americans suffer from some type of allergy each year. Allergies often occur along with other diseases as well, such as asthma, ear infections and sinusitis.

Some of the most common types of allergies include:

  • Environmental allergies often caused by pollens from trees, grasses or weeds
  • Food allergies, which are more common in children than adults
  • Insect sting or bite allergies from bugs like bees, wasps, hornets and fire ants
  • Drug allergies to prescription and over-the-counter medications

Other allergies include latex (found in balloons, rubber bands and gloves), pet dander, dust, mold and cockroaches. Nearly anywhere you go, you could potentially encounter allergy triggers, so it’s important to recognize the symptoms and how to best treat them.

What Are the Symptoms of an Allergic Reaction?

Mild symptoms may include hives or itching, but more severe symptoms may include swelling of the face or tongue, respiratory difficulty, wheezing, lethargy, dizziness, a drop in blood pressure or severe GI symptoms (typically signs of anaphylaxis).

Check out the table below to see which symptoms are associated with each common allergen.

Symptoms of Common Allergens Infographic

How Do You Treat Mild to Moderate Allergic Reactions?

Many mild to moderate allergic reactions can be treated at home or with over-the-counter medications. Dr. Culver helped explain how some of the most common allergens are treated.

Environmental Allergies

  • Avoid the allergens altogether
  • Take an antihistamine or antihistamine decongestant
  • Use topical nasal and skin medications
  • Take a leukotriene blocker (such as Singulair/Montelukast)
  • Wash hands, shower and wash all clothing after being exposed to an allergen
  • Use allergy immunotherapy (e.g., allergy shots)

If you suffer from environmental allergens, the AAAAI keeps an updated report of pollen and spore levels in your area so you can take precautions.

Food Allergies

  • Avoid the offending agent
  • Take an over-the-counter drug to temper the reaction
  • Treat severe food allergies with epinephrine

Insect Stings or Bites

  • If it’s a sting, carefully remove the stinger with a straight-edged object; do not pull or squeeze the stinger using tweezers or your fingers
  • Wash the area with soap and water
  • Apply a cold ice pack to the site to reduce swelling and pain
  • Take an over-the-counter pain reliever for pain and antihistamine to reduce any itching, swelling or hives
  • Treat severe reactions with epinephrine
  • Follow up with a doctor to determine allergic sensitization

Drug Allergies

  • Discontinue the medication and let your doctor know
  • Take an antihistamine to relieve mild symptoms such as a rash or hives
  • In severe cases, a bronchodilator or epinephrine may be needed

How Do You Treat Severe Reactions (Anaphylactic Shock)?

The most serious allergic reaction can cause anaphylaxis or anaphylactic shock. Anaphylactic shock can occur quickly after exposure, and if left untreated, it can lead to loss of consciousness, respiratory distress and cardiac arrest.

If someone is experiencing anaphylaxis, follow these steps:

  • Call 911 immediately for medical help
  • See if they have an epinephrine injector (EpiPen) and help them use it, if needed
  • Have them lie down and to their side, in case they need to throw up
  • Loosen any clothing that may be constricting blood flow
  • Do not give them anything to drink or eat
  • If they are not breathing, practice CPR until emergency services arrive

“Some people carry their personal epinephrine injector if it may be needed for severe reactions,” Dr. Culver said. “If there is any question about the severity of someone’s reaction, seek immediate medical attention—even if symptoms start to improve.”

What You Should Know If You Have Children

If you have allergies and related conditions, such as eczema and asthma, you may be concerned of passing these on to your kids. While there is no method currently to detect if your offspring will develop the same allergies, many parents can pass along their general allergy tendencies.

“It’s important to be on the lookout for triggers and similar reactions that you have had, but there is no reason, particularly in the case of food allergies, to avoid the early introduction of potentially allergic foods to infants if there is not a personal history of eczema or severe food allergy in a sibling,” Dr. Culver said. “If there are questions, a medical provider should be able to provide accurate answers.”

Get Help

Many people experience allergic reactions. If you are experiencing chronic and mild allergic symptoms, schedule an appointment to be evaluated by your primary care physician. They may recommend allergy testing to pinpoint the cause of your reaction and help you avoid triggers and future reactions.

If you are experiencing severe allergic symptoms, especially those involving a swelling of the tongue and throat or changes in heart rate, seek immediate medical attention as you may be suffering from anaphylactic shock.

To find a Banner Health medical provider near you, visit

Allergy and Immunology Safety