Editing Allergic conjunctivitis (section)

==Management==
A detailed history allows doctors to determine whether the presenting symptoms are due to an allergen or another source. Diagnostic tests such as conjunctival scrapings to look for eosinophils are helpful in determining the cause of the allergic response.<ref name="Ono"/> Antihistamines, mast cell stabilizers or dual activity drugs are safe and usually effective.<ref name="Ono"/> Corticosteroids are reserved for more severe cases of inflammation, and their use should be monitored by an optometrist due to possible side-effects.<ref name="Ono"/> When an allergen is identified, the person should avoid the allergen as much as possible.<ref name="Buckley"/>

===Non-pharmacological methods===
If the allergen is encountered and the symptoms are mild, a [[cold compress]] or artificial tears can be used to provide relief.{{cn|date=July 2022}}

===Mast cell stabilizers===
[[Mast cell]] stabilizers can help people with allergic conjunctivitis. They tend to have delayed results, but they have fewer side-effects than the other treatments and last much longer than those of [[antihistamines]]. Some people are given an antihistamine at the same time so that there is some relief of symptoms before the mast cell stabilizers becomes effective. Doctors commonly prescribe [[lodoxamide]] and [[nedocromil]] as mast cell stabilizers, which come as eye drops.{{cn|date=July 2022}}

A mast cell stabilizer is a class of non-steroid controller medicine that reduces the release of inflammation-causing chemicals from mast cells. They block a calcium channel essential for mast cell degranulation, stabilizing the cell, thus preventing the release of [[histamine]]. Decongestants may also be prescribed. Another common mast cell stabilizer that is used for treating allergic conjunctivitis is [[sodium cromoglicate]].

===Antihistamines===
Antihistamines such as [[diphenhydramine]] and [[chlorpheniramine]] are commonly used as treatment. People treated with H1 antihistamines exhibit reduced production of histamine and leukotrienes as well as downregulation of adhesion molecule expression on the vasculature which in turn attenuates allergic symptoms by 40–50%.<ref name="sphingo">{{Cite journal | last1 = Sun | first1 = W. Y. | last2 = Bonder | first2 = C. S. | doi = 10.1155/2012/154174 | title = Sphingolipids: A Potential Molecular Approach to Treat Allergic Inflammation | journal = Journal of Allergy | volume = 2012 | pages = 1–14 | year = 2012 | pmid = 23316248 | pmc =3536436 | doi-access = free }}</ref>

===Dual Activity Agents===
Dual-action medications are both mast cell stabilizers and antihistamines. They are the most common prescribed class of topical anti allergy agent. [[Olopatadine]] (Patanol, Pazeo)<ref>{{cite journal |vauthors=Rosenwasser LJ, O'Brien T, Weyne J |title=Mast cell stabilization and anti-histamine effects of olopatadine ophthalmic solution: a review of pre-clinical and clinical research |journal=Curr Med Res Opin |volume=21 |issue=9 |pages=1377–87 |date=September 2005 |pmid=16197656 |doi=10.1185/030079905X56547 |s2cid=8954933 }}</ref> and [[ketotifen fumarate]] (Alaway or Zaditor)<ref>{{cite journal |vauthors=Avunduk AM, Tekelioglu Y, Turk A, Akyol N |title=Comparison of the effects of ketotifen fumarate 0.025% and olopatadine HCl 0.1% ophthalmic solutions in seasonal allergic conjunctivities: a 30-day, randomized, double-masked, artificial tear substitute-controlled trial |journal=Clin Ther |volume=27 |issue=9 |pages=1392–402 |date=September 2005 |pmid=16291412 |doi=10.1016/j.clinthera.2005.09.013 }}</ref> are both commonly prescribed. Ketotifen is available without a prescription in some countries.{{citation needed|date=October 2022|reason=where?}} However, studies demonstrates that olopatadine is more effective than ketotifen in reducing the itching associated with allergic conjunctivitis in the antigen challenge model.<ref>{{cite journal |last1=Berdy |first1=Gregg J. |last2=Spangler |first2=Dennis L. |last3=Bensch |first3=George |last4=Berdy |first4=Susan S. |last5=Brusatti |first5=Robert C. |title=Comparison of the analgesic efficacy of concurrent ibuprofen and paracetamol with ibuprofen or paracetamol alone in the management of moderate to severe acute postoperative dental pain in adolescents and adults: A randomized, double-blind, placebo-controlled, parallel-group, single-dose, two-center, modified factorial study |journal=Clinical Therapeutics |date=May 17, 2000 |volume=22 |issue=7 |pages=826–833 |doi=10.1016/S0149-2918(00)80055-7 |url=https://www.clinicaltherapeutics.com/article/S0149-2918(00)80055-7/ |pmid=10945509|url-access=subscription }}</ref>

===Corticosteroids===
Ester based "soft" steroids such as [[loteprednol]] (Alrex) are typically sufficient to calm inflammation due to allergies, and carry a much lower risk of adverse reactions than amide based steroids.

A systematic review of 30 trials, with 17 different treatment comparisons found that all topical antihistamines and mast cell stabilizers included for comparison were effective in reducing symptoms of seasonal allergic conjunctivitis.<ref name="Castillo">{{cite journal |vauthors=Castillo M, Scott NW, Mustafa MZ, Mustafa MS, Azuara-Blanco A |title= Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis |journal=Cochrane Database Syst Rev|volume=2015 |issue= 6 |pages= CD009566 |date=2015 |pmid= 26028608 |doi= 10.1002/14651858.CD009566.pub2|pmc= 10616535 |hdl= 2164/6048 |hdl-access= free }}</ref> There was not enough evidence to determine differences in long-term efficacy among the treatments.<ref name="Castillo"/>

Many of the eye drops can cause burning and stinging, and have [[side-effects]]. Proper eye [[hygiene]] can improve symptoms, especially with contact lenses. Avoiding precipitants, such as pollen or mold can be preventative.{{citation needed|date=January 2013}}

===Immunotherapy===
[[Allergy immunotherapy|Allergen immunotherapy]] (AIT) treatment involves administering doses of allergens to accustom the body to substances that are generally harmless (pollen, house dust mites), thereby inducing specific long-term tolerance.<ref>Van Overtvelt L. et al. Immune mechanisms of allergen-specific sublingual immunotherapy. Revue française d'allergologie et d'immunologie clinique. 2006; 46: 713–720.</ref> Allergy immunotherapy can be administered orally (as sublingual tablets or sublingual drops), or by injections under the skin (subcutaneous). Discovered by Leonard Noon and John Freeman in 1911, allergy immunotherapy represents the only causative treatment for respiratory allergies.

Experimental research has targeted adhesion molecules known as [[selectins]] on epithelial cells. These molecules initiate the early capturing and margination of leukocytes from circulation. Selectin antagonists have been examined in preclinical studies, including cutaneous inflammation, allergy and ischemia-reperfusion injury. There are four classes of selectin blocking agents: (i) carbohydrate based inhibitors targeting all P-, E-, and L-selectins, (ii) antihuman selectin antibodies, (iii) a recombinant truncated form of PSGL-1 immunoglobulin fusion protein, and (iv) small-molecule inhibitors of selectins. Most selectin blockers have failed phase II/III clinical trials, or the studies were ceased due to their unfavorable pharmacokinetics or prohibitive cost.<ref name="sphingo"/> Sphingolipids, present in yeast like ''[[Saccharomyces cerevisiae]]'' and plants, have also shown mitigative effects in animal models of gene knockout mice.<ref name="sphingo"/>