Eye allergies, also known as allergic conjunctivitis, are a common condition, especially at this time of year, that can significantly impact a patient's quality of life. Understanding the symptoms, treatment options, and the importance of comprehensive management are crucial to providing optimal care for patients.

SYMPTOMS OF ALLERGIC CONJUNCTIVITIS

Allergic conjunctivitis generally presents with four primary symptoms:

1. Redness: Caused by the dilation of blood vessels in the conjunctiva.^1,2,4,5
2. Tearing: Increased tear production as a response to allergens.^1,2,4,5
3. Itching: A hallmark symptom due to the release of histamines.^1,2,4,5
4. Swelling: Inflammation of the conjunctiva and surrounding tissues.^1,4,5

Effective treatment requires addressing all these symptoms to provide comprehensive relief and improve patient outcomes.

TOPICAL TREATMENT OPTIONS

1. Antihistamine eyedrops: Antihistamine eye drops work by blocking histamine receptors, thereby reducing itching, redness, and swelling. They provide quick relief.^1,2,3,4,5 Newer generation antihistamines like olopatadine have the benefit of mast cell stabiliser properties too.⁶
2. Mast cell stabiliser eyedrops: Mast cell stabilisers prevent the release of histamine and other inflammatory mediators from mast cells. They are effective for long-term management and prevention of symptoms but need to be used before an allergic response has occurred.^1,2,3,4,5
3. Combination eyedrops: Combination drops that include both antihistamines and decongestants offer the benefits of immediate relief and long-term prevention.^1,2,3,5
4. Corticosteroid eyedrops: Ophthalmic steroids can be used for severe cases of allergic conjunctivitis to reduce inflammation. However, they should be used under medical supervision for short-term treatment due to potential side effects such as increased intraocular pressure and cataracts.^1,4
5. Decongestant eyedrops: While decongestant eye drops work by constricting blood vessels to reduce redness, they do not address itching, tearing, or swelling and are not suitable for long-term use. Prolonged use (beyond five days) can lead to rebound hyperaemia, where redness worsens once the drops are discontinued. Therefore, decongestants should be used with caution and only for short-term relief of redness.^3,5

IMPORTANCE OF COMPREHENSIVE TREATMENT

Dual-activity agents are considered the appropriate first-line therapy.¹ Pharmacists should emphasise the importance of using antihistamines and mast cell stabilisers over decongestants for the following reasons:

• Comprehensive symptom relief: Antihistamines and mast cell stabilisers address all four symptoms of allergic conjunctivitis, providing more effective and holistic relief.^1,5
• Prevention: Mast cell stabilisers help prevent the release of histamines, reducing the likelihood of future allergic reactions.^1,5
• Safety: Decongestants can cause side effects such as rebound hyperaemia and increased intraocular pressure, making them less suitable for long-term management.^3,5

Effective management of allergic conjunctivitis requires a comprehensive approach that addresses all symptoms – redness, tearing, itching, and swelling. Pharmacists play a crucial role in educating patients about the benefits of antihistamines and mast cell stabilisers for both treatment and prevention. By guiding patients towards appropriate and safe treatment options, you can help improve patient outcomes and quality of life.

REFERENCES 

1. Dupuis P, Prokopich C, Hynes A. et al. A contemporary look at allergic conjunctivitis. Allergy Asthma Clin Immunol 16, 5 (2020). Available from: https://doi.org/10.1186/s13223-020-0403-9. 
2. Eye Allergy. American College of Allergy, Asthma & Immunology. Available from: https://acaai.org/allergies/allergic-conditions/eye-allergy/. 
3. Choosing the Right Allergy Eye Drops for Allergic Conjunctivitis. Penn Medicine Becker ENT & Allergy. Available from: https://www.beckerentandallergy.com/blog/choosing-right-eye-drops-for-allergic-conjunctivitis. 
4. Allergic Conjunctivitis Frequently Asked Questions. Australasian Society of Clinical Immunology and Allergy. Available from: https://www.allergy.org.au/patients/allergic-rhinitis-hay-fever-and-sinusitis/allergic-conjunctivitis. 
5. Stop the Irritation: Get Instant Relief with Eye Drops for Allergic Conjunctivitis. Penn Medicine Becker ENT & Allergy. Available from: https://www.beckerentandallergy.com/blog/get-instant-relief-with-eye-drops-allergic-conjunctivitis. 
6. Olopatadine. Drugbank Online. 25 September 2024. Available from: https://go.drugbank.com/drugs/DB00768. 
7. Bielory L, Delgado L, Katelaris CH, et al. ICON: Diagnosis and management of allergic conjunctivitis. Annals of Allergy, Asthma & Immunology. 2020. 124 (2):118-134. ISSN 1081-1206. Available from: https://doi.org/10.1016/j.anai.2019.11.014.