Editing Allergic conjunctivitis (section)

==Causes==
The cause of allergic conjunctivitis is an [[allergic]] reaction of the body's immune system to an [[allergen]]. Allergic conjunctivitis is common in people who have other signs of allergic disease such as hay fever, asthma and eczema. {{citation needed|date=April 2014}}

Among the most common allergens that cause conjunctivitis are:<ref>{{cite web |last=Karakus |first=S |url=https://www.hopkinsmedicine.org/health/conditions-and-diseases/allergic-conjunctivitis| title=Allergic Conjunctivitis
|website=Johns Hopkins Medicine |access-date= 10 July 2021}}</ref>
* [[Pollen]] from trees, grass and ragweed
* Animal skin and secretions such as [[saliva]]
* [[Perfumes]]
* [[Cosmetics]]
* Skin medicines
* [[Air pollution]]
* [[Smoke]]
* [[Dust mites]]
* [[Balsam of Peru]] (used in food and drink for flavoring, in perfumes and toiletries for fragrance, and in medicine and pharmaceutical items for healing properties)
* Eye drops (A reaction to preservatives in eye drops can cause toxic conjunctivitis)
* Contact lens solution (some preservatives can irritate the eye over time resulting in conjunctivitis)
* [[Contact lens]] (conjunctivitis is also caused by repeated mechanical irritation of the conjunctiva by contact lens wearers)

Most cases of seasonal conjunctivitis are due to [[pollen]] and occur in the hay fever season, grass pollens in early summer and various other pollens and [[Mold (fungus)|moulds]] may cause symptoms later in the summer.<ref name="PatUK">{{cite web|url = http://patient.info/health/allergic-conjunctivitis-leaflet|title = What is conjunctivitis?|publisher = patient.info|access-date = 2010-04-06|archive-url = https://web.archive.org/web/20100430232351/http://www.patient.co.uk/health/Allergic-Conjunctivitis.htm|archive-date = 30 April 2010 |url-status = live}}</ref>