What is the treatment for allergic conjunctivitis?

Treatment of Allergic Conjunctivitis

Dual-action antihistamine/mast cell stabilizers (e.g., olopatadine, epinastine, ketotifen, azelastine) are the preferred first-line therapy for allergic conjunctivitis, providing both immediate symptom relief and prevention of symptoms. 1

First-Line Treatment Options

Non-Pharmacological Approaches

• Cold compresses and irrigation with preservative-free artificial tears or saline solution for mild symptoms 1
• Allergen avoidance strategies:
  • Identify and minimize exposure to potential allergens
  • Humidify ambient air to prevent tear evaporation
  • Avoid direct air drafts (fans, air conditioning, heaters)
  • For computer users: follow the 20-20-20 rule (every 20 minutes, look at something 20 feet away for 20 seconds)

Pharmacological Treatment

1. Dual-action antihistamine/mast cell stabilizers:

   • Examples: olopatadine, epinastine, ketotifen, azelastine
   • Mechanism: Provide both immediate symptom relief and prevention
   • Evidence shows olopatadine 0.77% has longer duration of action and better efficacy on ocular itch compared to lower concentrations 2

2. Pure mast cell stabilizers:

   • Examples: lodoxamide, nedocromil, pemirolast, cromolyn
   • Best for prevention rather than acute relief
   • Most effective when used before allergen exposure 1

3. Oral antihistamines:

   • Second-generation antihistamines (loratadine, cetirizine, fexofenadine) are effective for allergic conjunctivitis symptoms with less sedation than first-generation options 1
   • Note: Research shows that adding topical antihistamines (like Patanol/olopatadine) to oral antihistamines (like Claritin/loratadine) provides significantly better control of ocular itching than oral antihistamines alone 3

Second-Line Treatment Options

For moderate-to-severe or refractory symptoms:

1. Short-term topical corticosteroids:

   • Use limited to 1-2 weeks for severe symptoms unresponsive to other treatments
   • Loteprednol etabonate is preferred due to reduced risk of intraocular pressure elevation 1
   • FDA-approved for temporary relief of signs and symptoms of seasonal allergic conjunctivitis 4
   • Mechanism: Inhibits inflammatory response by inducing phospholipase A2 inhibitory proteins (lipocortins) 4

2. Topical immunomodulators:

   • Cyclosporine for long-term management of severe or refractory cases 1, 5
   • Tacrolimus may be effective for severe cases 1

Treatment Algorithm

1. For mild symptoms:

   • Start with non-pharmacological approaches (cold compresses, artificial tears)
   • If insufficient, add dual-action antihistamine/mast cell stabilizer eye drops

2. For moderate symptoms:

   • Dual-action antihistamine/mast cell stabilizer eye drops
   • Consider adding second-generation oral antihistamine if symptoms affect multiple systems (e.g., concurrent allergic rhinitis)

3. For severe or refractory symptoms:

   • Short-term topical corticosteroid (preferably loteprednol) for 1-2 weeks
   • Consider referral to ophthalmologist for specialized follow-up
   • For chronic severe cases, consider topical cyclosporine

Special Considerations

• Contact lens wearers: Remove lenses before instilling drops and wait at least 5 minutes before reinsertion 1
• Patients with comorbid asthma: Consider leukotriene receptor antagonists as part of treatment 1
• Vernal keratoconjunctivitis or atopic keratoconjunctivitis: Refer to an ophthalmologist 1, 5

Common Pitfalls to Avoid

• Avoid first-generation antihistamines due to sedation and anticholinergic effects 1
• Avoid prolonged use of topical ocular vasoconstrictors as they can cause rebound hyperemia ("conjunctivitis medicamentosa") 1
• Never use steroid eye drops without ophthalmologist supervision due to risks of increased intraocular pressure, cataract formation, and masking infection 1
• Avoid tap water for irrigation if corneal abrasion is suspected 1
• Avoid punctal plugs as they prevent flushing of allergens from the ocular surface 1

Monitoring

• Schedule follow-up within 1-2 weeks when initiating corticosteroid therapy to monitor for intraocular pressure elevation 1
• Regular monitoring to evaluate treatment effectiveness and adjust the plan as needed 1