What is the treatment for allergic conjunctivitis?

Treatment of Allergic Conjunctivitis

Dual-action topical agents (olopatadine, ketotifen, epinastine, or azelastine) are the first-line pharmacological treatment for allergic conjunctivitis, providing both immediate symptom relief and ongoing protection through combined antihistamine and mast cell stabilizer effects. 1, 2

First-Line Treatment Approach

Non-Pharmacological Measures

• Apply cold compresses and irrigate with refrigerated preservative-free artificial tears to dilute allergens and inflammatory mediators on the ocular surface 1, 2
• Implement allergen avoidance strategies including wearing sunglasses as a physical barrier against airborne allergens, using hypoallergenic bedding, washing clothes frequently, and bathing before bedtime 1
• Avoid eye rubbing, which can worsen symptoms and potentially lead to keratoconus, especially in patients with atopic disease 1

Pharmacological First-Line Treatment

• Start with dual-action topical agents (olopatadine, ketotifen, epinastine, or azelastine) as they provide rapid onset within 30 minutes and maintain efficacy for at least 8 hours 1, 2
• These agents are superior to oral antihistamines for isolated ocular symptoms and can be used for both acute relief and long-term prophylactic treatment without specified maximum duration 1, 3
• Dosing per FDA labeling: Olopatadine 0.1% one drop twice daily (or once daily for newer formulations), ketotifen one drop twice daily every 8-12 hours 4, 5
• Dual-action agents can be refrigerated for additional cooling relief upon instillation 1

Critical Pitfalls to Avoid

• Never use punctal plugs in allergic conjunctivitis as they prevent flushing of allergens and inflammatory mediators from the ocular surface 1
• Avoid oral antihistamines as primary treatment for isolated ocular symptoms, as they may worsen dry eye syndrome and impair the tear film's protective barrier 1, 2
• Avoid prolonged use of over-the-counter vasoconstrictor/antihistamine combinations (naphazoline, tetrahydrozoline products) as they can cause rebound hyperemia (conjunctivitis medicamentosa) with use beyond 10 days 6, 1
• Do not use topical antibiotics as they can induce toxicity and are not indicated for allergic conjunctivitis 1

Second-Line Treatment Options

When First-Line Treatment is Insufficient

• Mast cell stabilizers alone (cromolyn, lodoxamide, nedocromil, pemirolast) are better suited for prophylactic or longer-term treatment but require several days before optimal symptom relief is achieved 6, 2
• These agents are FDA-approved for chronic ocular allergy conditions involving corneal defects including vernal keratoconjunctivitis and atopic keratoconjunctivitis 6, 7
• Topical NSAIDs (ketorolac) can provide temporary relief of ocular itching but have been found inferior to dual-action agents like olopatadine and emedastine 6, 3

Third-Line Treatment for Severe Cases

Short-Term Topical Corticosteroids

• For inadequately controlled symptoms or acute exacerbations, add a brief 1-2 week course of loteprednol etabonate (low side-effect profile corticosteroid) 1, 2
• Strictly limit corticosteroid use to 1-2 weeks maximum due to risks of increased intraocular pressure, cataract formation, and secondary infections 1, 2
• Mandatory monitoring: Obtain baseline and periodic intraocular pressure measurements plus pupillary dilation to evaluate for glaucoma and cataract formation when using any corticosteroid 1
• Topical corticosteroids should only be used as a brief adjunct to antihistamine therapy, not as monotherapy 1

Escalation Strategy for Refractory Cases

If Symptoms Do Not Improve Within 48 Hours on Dual-Action Drops

• Add loteprednol etabonate for 1-2 weeks with appropriate IOP monitoring 1
• Reassess diagnosis and consider consultation with ophthalmology or allergy specialist 1

Severe or Refractory Cases Unresponsive to Above Treatments

• Consider topical cyclosporine 0.05% or tacrolimus for severe cases, particularly vernal or atopic keratoconjunctivitis 1, 8
• Cyclosporine 0.1% is FDA-approved for vernal keratoconjunctivitis in children and adults 1
• Topical cyclosporine may allow for reduced use of topical steroids and is effective as a disease-modifying treatment 1, 8
• For eyelid involvement in patients 2 years or older, use pimecrolimus cream 1% or topical tacrolimus ointment (0.03% for ages 2-15 years; 0.03% or 0.1% for ages 16+) 1
• Warning: Tacrolimus or pimecrolimus may increase susceptibility to herpes simplex keratitis 1

Special Considerations for Vernal/Atopic Keratoconjunctivitis

• Topical corticosteroids are usually necessary to control severe symptoms and signs in these conditions 1
• Inform patients about potential complications of corticosteroid therapy and employ strategies to minimize corticosteroid use 1
• For severe atopic keratoconjunctivitis unresponsive to topical therapy, consider supratarsal injection of corticosteroid 1
• Systemic immunosuppression is rarely warranted but options include montelukast, interferons, and oral T-cell inhibitors such as cyclosporine and tacrolimus 1

Duration of Treatment

Seasonal Allergic Conjunctivitis

• Use dual-action agents throughout the allergen exposure season with no specified maximum duration 1, 2
• Unlike vasoconstrictors or corticosteroids, dual-action agents have no specified maximum treatment duration in guidelines, supporting extended use without risks 2

Perennial Allergic Conjunctivitis

• Use dual-action agents continuously as long as allergen exposure persists, with reassessment of need at regular follow-up visits based on symptom control 1

Follow-Up and Monitoring

• Frequency of follow-up visits should be based on disease severity, etiology, and treatment response 1
• Monitor for keratoconus in patients with allergic conjunctivitis and atopic disease, as adequate control of allergy and eye rubbing are important to decrease progression of ectasia 1
• If corticosteroids are used in chronic or recurrent conjunctivitis, baseline and periodic IOP measurement and pupillary dilation must be performed 1

When to Refer

• Consult an allergist or ophthalmologist for patients with disease that cannot be adequately controlled with topical medications 1
• Consider allergen-specific immunotherapy (subcutaneous or sublingual) for achieving hyposensitization, though usage may be limited by expense, long-term patient commitment, and risk of anaphylaxis 1