Allergies occur when your immune system overreacts to common substances that are normally harmless such as food, dust, pet dander and seasonal pollen, called allergens. Depending on your age, general health and severity of your allergy symptoms, your primary care provider might refer to you an immunologist who specializes in treating allergies.

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Common types and symptoms of allergies

In the United States, the most common allergens are:

  • Animal dander, urine or oil from skin.
  • Bee stings.
  • Chemicals used for manufacturing.
  • Cockroaches and their waste.
  • Feathers.
  • Food.
  • Household dust, dust mites and their waste.
  • Latex.
  • Medicine.
  • Mold.
  • Pollen.

Allergic reactions can happen anywhere in the body. They most commonly occur in the skin, eyes, stomach lining, nose, sinuses, throat and lungs, where immune system cells are found to fight off germs that are breathed in, swallowed or that come in contact with the skin.


Allergic reactions can cause these symptoms:

  • Asthma symptoms, such as shortness of breath, coughing, wheezing.
  • Hives or itchy welts.
  • Itchy rash.
  • Red, itchy, dry skin.
  • Red, itchy, watery eyes.
  • Stuffy nose, sneezing, itching or runny nose, and itching in ears or roof of mouth.

You should see your UCHealth provider if you are experiencing any of these, especially if you suspect the symptom is being caused by a known allergen.

What is anaphylaxis?

Anaphylaxis is a potentially life-threatening allergic reaction, so it requires emergency treatment.

Symptoms usually occur within seconds or minutes of exposure to an allergen like peanuts or bee stings, but sometimes they can occur 30 minutes or more after exposure. It causes your immune system to flood your body with chemicals that can cause you to go into shock. Your blood pressure suddenly drops and your airways constrict, blocking breathing.

Other signs and symptoms include:

  • Dizziness or fainting.
  • Nausea, vomiting or diarrhea.
  • Skin reactions, including hives and itching, and flushed or pale skin.
  • Weak and rapid pulse.

Anaphylaxis requires an injection of epinephrine and a follow-up trip to an emergency room. If you or someone near you is experiencing anaphylaxis, call 911 or go to an emergency room immediately.

Risk factors and preventing allergies

Allergies can affect anyone at any age, but allergies are more common in children. A first-time reaction can happen at any age, or come back after many years of remission. If you have any of these factors, you may be at a higher risk for developing an allergy:

  • Asthma.
  • Environmental irritants.
  • Family history.
  • Stress.

Managing these risk factors can help prevent allergies.

Preventative steps

In addition to risk management, you can try these preventative steps:

  • Avoid known triggers. If you’re allergic to pollen—commonly called hay fever—stay inside and shut all windows and doors closed when pollen is high. Consider wearing a face mask when working in the yard. If you’re allergic to dust mites, wash your bedding, curtains and clothing in hot water often. Consider using dust mite covers over your mattress and pillow.
  • Track your symptoms. Record symptoms and when they occur, what you eat and anything that seems to help. Share this information with your provider.
  • Wear a medical alert bracelet. If you’ve had a severe allergic reaction like anaphylaxis, a medical alert bracelet or necklace lets others know that you have a serious allergy in case you have a reaction and you’re unable to communicate.

Your health care provider will also have suggestions for staying away from the allergens that cause reactions.

Treating allergies

Your UCHealth provider will work with you on a personalized treatment plan to treat your symptoms, which may include a referral to an immunologist who specializes in allergies. This plan will depend on your symptoms, age, general health and on the severity of the condition.

In addition to avoiding allergens, your treatment plan can include:

  • Medicine. Nasal sprays work to decrease nasal congestion, stuffiness and postnasal drip. Antihistamines are helpful for itchiness and hives. Decongestants are used to treat stuffiness in the nose and other symptoms linked to colds and allergies. If you need medicine for asthma or difficulty breathing due to allergies, we will determine treatment based on the severity of your symptoms. If you have a severe allergy, you need to carry an emergency epinephrine shot at all times to reduce symptoms until you get emergency treatment.
  • Allergy shots (immunotherapy). Used to treat people who have hay fever (allergic rhinitis), conjunctivitis, asthma and for people with a stinging insect allergy (bee venom allergy). A mixture of the many allergens to which you are allergic is made and injected into your arm on a weekly basis until a maximum dose is reached. Then the number of injections is decreased over time. Most of our patients get better with allergy shots, usually taking 12 to 18 months to achieve a clear reduction in symptoms. Some people see improvement in just 6–8 months.
  • Sublingual immunotherapy (SLIT). A newer type of immunotherapy, which can be taken by mouth daily at home. It is an effective alternative to allergy shots, but it is currently only available for a few allergens.

Living with allergies

Fortunately, most of our patients enjoy a high quality of life by staying away from allergens, getting immunotherapy and taking medicine as needed. Your primary care provider is ready to help.


American Academy of Allergy Asthma & Immunology (AAAAI). Allergies (

MedlinePlus: National Library of Medicine. Allergy (

Center for Disease Control and Prevention (CDC). Allergies and Hay Fever (

National Center for Biotechnology Information (NCBI): National Library of Medicine. Allergies: Overview (