Editing Allergen (section)

== Seasonal ==
Seasonal allergy symptoms are commonly experienced during specific parts of the year, usually during spring, summer or fall when certain trees or grasses pollinate. This depends on the kind of tree or grass. For instance, some trees such as [[oak]], [[elm]], and [[maple]] pollinate in the spring, while grasses such as [[Cynodon dactylon|Bermuda]], [[Timothy (grass)|timothy]] and [[Orchard grass|orchard]] pollinate in the summer.

Grass allergy is generally linked to [[hay fever]] because their symptoms and causes are somehow similar to each other. Symptoms include [[rhinitis]], which causes [[sneezing]] and a [[runny nose]], as well as [[allergic conjunctivitis]], which includes watering and itchy eyes.<ref name="Seasonal Allergy">{{cite web |url=http://seasonalallergies.us/ |title=Seasonal Allergy — What to Know | work = Seasonal Allergy |access-date=9 April 2010 |archive-url=https://web.archive.org/web/20100414063236/http://seasonalallergies.us/ |archive-date=14 April 2010 |url-status=dead }}</ref> Also an initial tickle on the roof of the mouth or in the back of the throat may be experienced.

Also, depending on the season, the symptoms may be more severe and people may experience [[coughing]], [[wheezing]], and irritability. A few people even become depressed, lose their [[appetite]], or have problems sleeping.<ref>{{cite journal | pmc=9618478 | date=2022 | title=Efficacy of Proactive Topical Antihistamine Use in Patients with Seasonal Allergic Conjunctivitis | journal=Advances in Therapy | volume=39 | issue=12 | pages=5568–5581 | doi=10.1007/s12325-022-02324-w | pmid=36244054 | vauthors = Fukushima A, Miyazaki D, Kishimoto H, Ebihara N }}</ref> Moreover, since the [[sinuses]] may also become congested, some people experience [[headaches]].<ref name="Merck">{{cite web | vauthors = Fernandez J | work =The Merck Manual | publisher = Merck & Co., Inc. | location = Rahway, NJ, USA |url=http://www.merck.com/mmhe/sec16/ch185/ch185b.html |title=Seasonal Allergies
|access-date=9 April 2010| archive-url= https://web.archive.org/web/20100412052011/http://www.merck.com/mmhe/sec16/ch185/ch185b.html| archive-date= 12 April 2010 | url-status= live}}</ref>

If both parents have had allergies in the past, there is a 66% chance for the individual to experience seasonal allergies, and the risk lowers to 60% if just one parent has had allergies.<ref>{{Cite journal |last1=Ober |first1=Carole |last2=Yao |first2=Tsung-Chieh |date=2011 |title=The genetics of asthma and allergic disease: a 21st century perspective |journal=Immunological Reviews |language=en |volume=242 |issue=1 |pages=10–30 |doi=10.1111/j.1600-065X.2011.01029.x |issn=1600-065X |pmc=3151648 |pmid=21682736}}</ref> The immune system also has strong influence on seasonal allergies, because it reacts differently to diverse allergens like pollen. When an allergen enters the body of an individual that is predisposed to allergies, it triggers an immune reaction and the production of antibodies. These allergen antibodies migrate to mast cells lining the nose, eyes, and lungs. When an allergen drifts into the nose more than once, mast cells release a slew of chemicals or histamines that irritate and inflame the moist membranes lining the nose and produce the symptoms of an allergic reaction: scratchy throat, itching, sneezing and watery eyes. Some symptoms that differentiate allergies from a cold include:<ref>{{cite web | url = https://www.cbc.ca/news/health/seasonal-allergies-something-to-sneeze-at-1.930532 | title = Seasonal allergies: Something to sneeze at | archive-url = https://web.archive.org/web/20100902081131/http://www.cbc.ca/health/story/2010/03/19/f-seasonal-allergies-symptoms.html | archive-date = 2 September 2010 | work = CBS News | url-status = live | access-date = 31 August 2010 }}</ref>
* No fever.
* Mucous secretions are runny and clear.
* Sneezes occurring in rapid and several sequences.
* Itchy throat, ears and nose.
* These symptoms usually last longer than 7–10 days.

Among seasonal allergies, there are some allergens that fuse together and produce a new type of allergy. For instance, grass pollen allergens cross-react with food allergy proteins in vegetables such as onion, lettuce, carrots, celery, and corn. Besides, the cousins of [[birch]] pollen allergens, like apples, grapes, peaches, celery, and apricots, produce severe itching in the ears and throat. The cypress pollen allergy brings a cross reactivity between diverse species like [[olive]], [[privet]], [[Fraxinus|ash]] and Russian olive tree pollen allergens. In some rural areas, there is another form of seasonal grass allergy, combining airborne particles of pollen mixed with [[mold]].<ref>{{cite web | url = http://www.seasonalallergies.us/ | title = Seasonal Allergies: What to know | archive-url = https://web.archive.org/web/20100414063236/http://seasonalallergies.us/ | archive-date=14 April 2010 | work = Seasonal Allergy | access-date = 31 August 2010 }}</ref>
Recent research has suggested that humans might develop allergies as a defense to fight off parasites. According to Yale University Immunologist [[Ruslan Medzhitov]], protease allergens cleave the same sensor proteins that evolved to detect proteases produced by the parasitic worms.<ref>{{cite web | url = http://www.abc.net.au/science/articles/2010/04/12/2870397.htm/ | title = Parasites behind seasonal allergies | archive-url = https://web.archive.org/web/20100908113331/http://www.abc.net.au/science/articles/2010/04/12/2870397.htm | archive-date=8 September 2010 | work = ABC Science | date = 12 April 2010 | access-date = 31 August 2010 }}</ref> Additionally, a new report on seasonal allergies called "Extreme allergies and Global Warming", have found that many allergy triggers are worsening due to climate change. 16 states in the United States were named as "Allergen Hotspots" for large increases in allergenic tree pollen if global warming pollution keeps increasing. Therefore, researchers on this report claimed that global warming is bad news for millions of asthmatics in the United States whose asthma attacks are triggered by seasonal allergies.<ref>{{cite web | vauthors = Weinmann A | date = 14 April 2010 | url = http://www.nwf.org/News-and-Magazines/Media-Center/News-by-Topic/Global-Warming/2010/04-14-10-Seasonal-Allergies-Getting-Worse-From-Climate-Change.aspx/ | title = Seasonal allergies getting worse from Climate Change | archive-url = https://web.archive.org/web/20100806132853/http://www.nwf.org/News-and-Magazines/Media-Center/News-by-Topic/Global-Warming/2010/04-14-10-Seasonal-Allergies-Getting-Worse-From-Climate-Change.aspx | archive-date=6 August 2010 | work = National Wildlife Federation. Media Center.| access-date = 31 August 2010 }}</ref> Seasonal allergies are one of the main triggers for asthma, along with colds or flu, cigarette smoke and exercise. In Canada, for example, up to 75% of asthmatics also have seasonal allergies.<ref>{{cite web | url = http://www.asthma.ca/allergies/asthmaandallergiessymptoms.html/ | title = Asthma and Allergies: The Symptoms | archive-url = https://web.archive.org/web/20100917191419/http://asthma.ca/allergies/asthmaandallergiessymptoms.html | archive-date=17 September 2010 | work = Asthma Society of Canada | access-date = 31 August 2010 }}</ref>

=== Diagnosis ===

Based on the symptoms seen on the patient, the answers given in terms of symptom evaluation and a physical exam, doctors can make a diagnosis to identify if the patient has a seasonal allergy. After performing the diagnosis, the doctor is able to tell the main cause of the allergic reaction and recommend the treatment to follow. Two tests have to be done in order to determine the cause: a blood test and a skin test. Allergists do skin tests in one of two ways: either dropping some purified liquid of the allergen onto the skin and pricking the area with a small needle; or injecting a small amount of allergen under the skin.<ref>{{cite web | url = http://kidshealth.org/parent/medical/allergies/seasonal_allergies.html/ | title = Seasonal Allergies | archive-url = https://web.archive.org/web/20100516031605/http://kidshealth.org/parent/medical/allergies/seasonal_allergies.html | archive-date=16 May 2010 | work = Kids Health | access-date = 31 August 2010 }}</ref>

Alternative tools are available to identify seasonal allergies, such as laboratory tests, imaging tests, and nasal endoscopy. In the laboratory tests, the doctor will take a nasal smear and it will be examined microscopically for factors that may indicate a cause: increased numbers of eosinophils (white blood cells), which indicates an allergic condition. If there is a high count of eosinophils, an allergic condition might be present.<ref>{{Cite web | vauthors = Liesveld J |title=Eosinophilia - Hematology and Oncology |url=https://www.merckmanuals.com/professional/hematology-and-oncology/eosinophilic-disorders/eosinophilia |access-date=2022-06-01 |website=Merck Manuals Professional Edition |language=en-US}}</ref>

Another laboratory test is the blood test for IgE (immunoglobulin production), such as the [[radioallergosorbent test]] (RAST) or the more recent enzyme allergosorbent tests (EAST), implemented to detect high levels of allergen-specific IgE in response to particular allergens. Although blood tests are less accurate than the skin tests, they can be performed on patients unable to undergo skin testing. Imaging tests can be useful to detect sinusitis in people who have chronic rhinitis, and they can work when other test results are ambiguous. There is also nasal endoscopy, wherein a tube is inserted through the nose with a small camera to view the passageways and examine any irregularities in the nose structure. Endoscopy can be used for some cases of chronic or unresponsive seasonal rhinitis.<ref>{{cite news | url = http://health.nytimes.com/health/guides/disease/allergic-rhinitis/diagnosis.html | title = Allergic Rhinitis | archive-url = https://web.archive.org/web/20100904064016/http://health.nytimes.com/health/guides/disease/allergic-rhinitis/diagnosis.html | archive-date=4 September 2010 | work = New York Times Health Guide | access-date = 31 August 2010 }}</ref>