Allergic rhinitis

"Hay fever" redirects here. For other uses, see Hay fever (disambiguation).

Allergic rhinitis
Other namesHay fever, pollenosis
SEM Microscope image of Pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), prairie hollyhock (Sidalcea malviflora), oriental lily (Lilium auratum), evening primrose (Oenothera fruticosa), and castor bean (Ricinus communis).
SpecialtyAllergy and immunology
SymptomsStuffy itchy nose, sneezing, red, itchy, and watery eyes, swelling around the eyes, itchy ears[1]
Usual onset20 to 40 years old[2]
CausesGenetic and environmental factors[3]
Risk factorsAsthma, allergic conjunctivitis, atopic dermatitis[2]
Diagnostic methodBased on symptoms, skin prick test, blood tests for specific antibodies[4]
Differential diagnosisCommon cold[3]
PreventionExposure to animals early in life[3]
MedicationNasal steroids, antihistamines such as loratadine, cromolyn sodium, leukotriene receptor antagonists such as montelukast, allergen immunotherapy[5][6]
Frequency~20% (Western countries)[2][7]

Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air.[6] It is classified as a type I hypersensitivity reaction.[8] Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes.[1] The fluid from the nose is usually clear.[2] Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study.[2][9] Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure.[3] Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis.[2]

Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust, or mold.[3] Inherited genetics and environmental exposures contribute to the development of allergies.[3] Growing up on a farm and having multiple siblings decreases this risk.[2] The underlying mechanism involves IgE antibodies that attach to an allergen, and subsequently result in the release of inflammatory chemicals such as histamine from mast cells.[2] It causes mucous membranes in the nose, eyes and throat to become inflamed and itchy as they work to eject the allergen.[10] Diagnosis is typically based on a combination of symptoms and a skin prick test or blood tests for allergen-specific IgE antibodies.[4] These tests, however, can give false positives.[4] The symptoms of allergies resemble those of the common cold; however, they often last for more than two weeks and, despite the common name, typically do not include a fever.[3]

Exposure to animals early in life might reduce the risk of developing these specific allergies.[3] Several different types of medications reduce allergic symptoms, including nasal steroids, intranasal antihistamines such as olopatadine or azelastine, 2nd generation oral antihistamines such as loratadine, desloratadine, cetirizine, or fexofenadine; the mast cell stabilizer cromolyn sodium, and leukotriene receptor antagonists such as montelukast.[11][5] Oftentimes, medications do not completely control symptoms, and they may also have side effects.[2] Exposing people to larger and larger amounts of allergen, known as allergen immunotherapy, is often effective and is used when first line treatments fail to control symptoms.[6] The allergen can be given as an injection under the skin or as a tablet under the tongue.[6] Treatment typically lasts three to five years, after which benefits may be prolonged.[6]

Allergic rhinitis is the type of allergy that affects the greatest number of people.[12] In Western countries, between 10 and 30% of people are affected in a given year.[2][7] It is most common between the ages of twenty and forty.[2] The first accurate description is from the 10th-century physician Abu Bakr al-Razi.[13] In 1859, Charles Blackley identified pollen as the cause.[14] In 1906, the mechanism was determined by Clemens von Pirquet.[12] The link with hay came about due to an early (and incorrect) theory that the symptoms were brought about by the smell of new hay.[15][16]

  1. ^ a b "Environmental Allergies: Symptoms". NIAID. April 22, 2015. Archived from the original on June 18, 2015. Retrieved June 19, 2015.
  2. ^ a b c d e f g h i j k Wheatley LM, Togias A (January 2015). "Clinical practice. Allergic rhinitis". The New England Journal of Medicine. 372 (5): 456–63. doi:10.1056/NEJMcp1412282. PMC 4324099. PMID 25629743.
  3. ^ a b c d e f g h "Cause of Environmental Allergies". NIAID. April 22, 2015. Archived from the original on June 17, 2015. Retrieved June 17, 2015.
  4. ^ a b c "Environmental Allergies: Diagnosis". NIAID. May 12, 2015. Archived from the original on June 17, 2015. Retrieved June 19, 2015.
  5. ^ a b "Environmental Allergies: Treatments". NIAID. April 22, 2015. Archived from the original on June 17, 2015. Retrieved June 17, 2015.
  6. ^ a b c d e "Immunotherapy for Environmental Allergies". NIAID. May 12, 2015. Archived from the original on June 17, 2015. Retrieved June 19, 2015.
  7. ^ a b Dykewicz MS, Hamilos DL (February 2010). "Rhinitis and sinusitis". The Journal of Allergy and Clinical Immunology. 125 (2 Suppl 2): S103-15. doi:10.1016/j.jaci.2009.12.989. PMID 20176255.
  8. ^ "Types of Allergic Diseases". web.archive.org. June 17, 2015. Retrieved November 9, 2024.
  9. ^ Cite error: The named reference Cov2018 was invoked but never defined (see the help page).
  10. ^ "Allergic Rhinitis (Hay Fever): Symptoms, Diagnosis & Treatment". Cleveland Clinic. Archived from the original on March 23, 2022. Retrieved March 23, 2022.
  11. ^ Bernstein, Jonathan A.; Bernstein, Joshua S.; Makol, Richika; Ward, Stephanie (March 12, 2024). "Allergic Rhinitis: A Review". JAMA. 331 (10): 866. doi:10.1001/jama.2024.0530.
  12. ^ a b Fireman P (2002). Pediatric otolaryngology vol 2 (4th ed.). Philadelphia, Pa.: W. B. Saunders. p. 1065. ISBN 9789997619846. Archived from the original on July 25, 2020. Retrieved September 23, 2016.
  13. ^ Colgan R (2009). Advice to the young physician on the art of medicine. New York: Springer. p. 31. ISBN 9781441910349. Archived from the original on September 8, 2017.
  14. ^ Justin Parkinson (July 1, 2014). "John Bostock: The man who 'discovered' hay fever". BBC News Magazine. Archived from the original on July 31, 2015. Retrieved June 19, 2015.
  15. ^ Hall M (May 19, 1838). "Dr. Marshall Hall on Diseases of the Respiratory System; III. Hay Asthma". The Lancet. 30 (768): 245. doi:10.1016/S0140-6736(02)95895-2. Archived from the original on July 25, 2020. Retrieved September 23, 2016. With respect to what is termed the exciting cause of the disease, since the attention of the public has been turned to the subject an idea has very generally prevailed, that it is produced by the effluvium from new hay, and it has hence obtained the popular name of hay fever. [...] the effluvium from hay has no connection with the disease.
  16. ^ History of Allergy. Karger Medical and Scientific Publishers. 2014. p. 62. ISBN 9783318021950. Archived from the original on June 10, 2016.