An allergy is the overreaction of the immune system to something that’s harmless. Allergic rhinitis is irritation and swelling in the nose. A chain of events starts when allergens are breathed in from the air. The most common are from grasses, trees, weeds, or animals.

Once in the nose, mast cells release histamine. This causes swelling in the blood vessels and mucous membranes in the lining of the nose. A reaction can happen quickly and involves:

  • Runny or itchy nose
  • Watery, itchy, or red eyes
  • Sneezing
  • Coughing

This is a very common problem for millions of people in the US. But, they don’t happen to all people.

Allergic Rhinitis With Severe Swelling of the Nasal Tissues

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Types of Allergic Rhinitis

There are 2 types:

  • Seasonal—Happens mainly in the spring, summer, or early fall. Causes are from grasses, trees, weeds, or mold spores in the air.
  • Perennial—Happens year-round. Causes are from dust mites, cockroaches, animal dander, or mold spores. For some, food allergies may cause this type.

Problems Linked to Allergic Rhinitis

In most cases, allergies are mild and only cause discomfort. But for many people, they can be tied to:


Allergic rhinitis. American College of Allergy, Asthma & Immunology website. Available at: Accessed October 15, 2018.

Allergic rhinitis. EBSCO DynaMed Plus website. Available at: Updated July 9, 2018. Accessed October 15, 2018.

Allergic rhinitis. Merck Manual Professional Version website. Available at:,-autoimmune,-and-other-hypersensitivity-disorders/allergic-rhinitis. Updated January 2018. Accessed October 15, 2018.

Last reviewed September 2018 by EBSCO Medical Review Board Marcin Chwistek, MD  Last Updated: 10/15/2018