An allergist (allergist/immunologist) is a doctor who diagnoses and treats allergies, asthma and immunologic conditions. In addition to medical school and residency, allergists have two to three years of special training in allergy and immunology. Allergists can help you manage your allergies or asthma and avoid serious reactions.

Photo of allergist performing allergy skin testing.
An allergist can use a small amount of allergen to see if you have a reaction to grasses, trees, foods, pet dander and more.

What is an allergist?

An allergist (allergist/immunologist) is a doctor who specializes in certain conditions that affect your immune system. Your immune system is made up of special cells, organs and tissues that fight off disease. Types of immune system disorders an allergist treats include:

  • Allergies and allergic disorders. You get allergies when your immune system overreacts to something you eat, breathe in (inhale) or touch.
  • Asthma. Asthma is an inflammation of the airways in your lungs. Asthma attacks are usually brought on by triggers in the environment around you.
  • Primary immunodeficiency disorders. These are genetic disorders that keep your immune system from working properly. There are over 200 primary immunodeficiency disorders.

What is a pediatric allergist?

A pediatric allergist diagnoses and treats allergies, asthma and immune disorders in infants, children and teens.


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What is the difference between allergist and immunologist?

“Allergist” is usually short for an allergist/immunologist who focuses on treating allergies and asthma and who may also treat immune disorders. An immunologist is also an allergist/immunologist, but usually one who specializes in treating immune disorders or medical research on the immune system.

What does an allergist do?

An allergist diagnoses and treats problems with your immune system. An allergist can:

  • Test for allergies to foods, pollens (grass, trees, weeds), pet dander, mold and other triggers.
  • Test your lung function and diagnose asthma.
  • Prescribe medications or devices to prevent, treat or reduce the severity of allergic reactions and asthma attacks.
  • Recommend lifestyle changes to help avoid asthma or allergy triggers.
  • Give allergy shots or other forms of immunotherapy to help reduce allergic reactions.
  • Diagnose immunodeficiency disorders.
  • Recommend ways to avoid infection while living with an immune disorder.
  • Administer intravenous immunoglobulin (IVIG) to treat certain immune disorders.
  • Perform drug desensitization so you can safely take important medications.


What conditions does an allergist treat?

Some conditions allergists commonly treat include:

Why do people see an allergist?

You might see an allergist to:

  • Get tested for allergies or asthma.
  • Receive treatment for allergies or asthma.
  • Manage an immune system disorder.


When should you see an allergist?

You should see an allergist, or ask your primary care physician if they recommend seeing an allergist, if:

  • You have severe allergic reactions that include hives, face or tongue swelling or trouble breathing.
  • You have allergies but need to find out what’s triggering them.
  • You have allergies or asthma that you don’t feel are well controlled, even with medication or lifestyle changes.
  • Allergies or asthma affect your quality of life or keep you from work or activities you enjoy.
  • You wheeze, cough or feel short of breath frequently, especially after exercise or at night.
  • You’re often sick or it takes you a long time to get over colds or other routine illnesses.

How does an allergist test for allergies?

Depending on what kind of allergy they’re looking for, an allergist might use one or more types of tests, including:

  • Skin prick/scratch tests. Skin prick tests use a small amount of allergen on an applicator. Your allergist scratches your skin lightly with the applicator and waits to see if it causes a reaction.
  • Blood tests. A lab tests a sample of your blood to see if you have signs of allergies to specific substances.
  • Food challenge tests. During a food challenge test, your allergist gives you increasing amounts of a food that you might be allergic to. They monitor you for an allergic reaction.

In addition to allergy testing, your allergist appointment may also include:

  • Lung function testing (spirometry, pulmonary function testing). This is a test to measure your lung function. It helps in the diagnosis and management of asthma.
  • Instructions on how to use medical devices. Your provider might prescribe and demonstrate the use of epinephrine injectors for severe allergic reactions or inhalers and nebulizers for asthma.

How do you become an allergist?

To become an allergist in the U.S., you must first complete medical school and a three-year residency in either internal medicine or pediatrics. This includes passing the exam for either the American Board of Internal Medicine or the American Board of Pediatrics. You then have to complete two to three more years of study in allergy and immunology. Finally, you have to pass an exam to become certified by the American Board of Allergy and Immunology.

A note from Cleveland Clinic

Allergies, asthma and immune conditions can affect your daily life and cause serious reactions. An allergist can help you identify allergy or asthma triggers, prescribe treatments to help your symptoms and suggest lifestyle changes to avoid triggers. They can help you understand and manage your condition so it doesn’t disrupt your life.

Medically Reviewed

Last reviewed on 08/18/2022.

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