What is the appropriate management of allergic conjunctivitis?

Management of Allergic Conjunctivitis

Start with dual-action topical agents (olopatadine, ketotifen, epinastine, or azelastine) as first-line therapy for allergic conjunctivitis, as these provide both immediate symptom relief and ongoing protection through combined antihistamine and mast cell stabilizer effects. 1, 2

First-Line Treatment Approach

Pharmacological therapy:

• Prescribe dual-action agents (olopatadine, ketotifen, epinastine, or azelastine) twice daily as the most effective initial treatment, providing rapid onset while preventing recurrent episodes 1, 2
• For children ≥3 years, ketotifen is dosed as 1 drop in affected eye(s) twice daily, every 8-12 hours 3
• Store drops in the refrigerator for additional cooling relief upon instillation 1

Non-pharmacological measures (implement concurrently):

• Apply cold compresses for immediate symptomatic relief 1, 2
• Use refrigerated preservative-free artificial tears 4 times daily to dilute allergens and inflammatory mediators 1, 2
• Wear sunglasses as a physical barrier against airborne allergens 1, 2
• Implement allergen avoidance: hypoallergenic bedding, eyelid cleansers to remove allergens, frequent clothes washing, and showering before bedtime 1, 2
• Counsel patients to avoid eye rubbing, which can worsen symptoms and potentially lead to keratoconus, especially in atopic patients 1, 2

Second-Line Treatment (For Prophylaxis or Chronic Cases)

If dual-action agents are insufficient or for long-term prophylaxis:

• Mast cell stabilizers alone (cromolyn, lodoxamide, nedocromil, pemirolast) require several days to achieve optimal relief and are better suited for prophylactic or longer-term treatment rather than acute symptom control 1, 2
• Topical NSAIDs (ketorolac) provide temporary relief of ocular itching 4, 2

Critical pitfall: Avoid chronic use of over-the-counter antihistamine/vasoconstrictor combinations (naphazoline/pheniramine) beyond 10 days, as prolonged vasoconstrictor use causes rebound hyperemia (conjunctivitis medicamentosa) 1, 2

Third-Line Treatment (Severe or Inadequately Controlled Cases)

If symptoms persist after 48 hours on dual-action agents:

• Add a brief 1-2 week course only of loteprednol etabonate (low side-effect profile topical corticosteroid) 1, 2
• Mandatory monitoring: Obtain baseline intraocular pressure (IOP) measurement and perform pupillary dilation to evaluate for glaucoma and cataract formation 1, 2
• Continue periodic IOP monitoring throughout corticosteroid use 1, 2
• Never extend corticosteroid use beyond 2 weeks without specialist consultation due to risks of elevated IOP, cataract formation, and secondary infections 1, 2

Critical pitfall: Avoid oral antihistamines as primary treatment—they worsen dry eye syndrome and impair the tear film's protective barrier 1, 2

Fourth-Line Treatment (Refractory or Severe Subtypes)

For vernal keratoconjunctivitis (VKC) or atopic keratoconjunctivitis (AKC) unresponsive to above treatments:

• Topical cyclosporine 0.1% is FDA-approved for VKC in children and adults 1
• Alternatively, use cyclosporine 0.05% at least 4 times daily or tacrolimus 0.03-0.1% 1, 2
• These immunomodulators allow for reduced corticosteroid dependence and demonstrate symptom reduction after 2 weeks 1, 2
• For eyelid involvement in patients ≥2 years, apply tacrolimus ointment 0.03% (ages 2-15) or 0.03-0.1% (ages 16+) 1
• Warning: Tacrolimus or pimecrolimus may increase susceptibility to herpes simplex keratitis 1

For sight-threatening atopic keratoconjunctivitis not responsive to topical therapy:

• Consider supratarsal corticosteroid injection 1, 2
• Systemic immunosuppression (montelukast, interferons, oral cyclosporine or tacrolimus) is rarely warranted but may be necessary 1, 2

Critical Pitfalls to Avoid

• Never use punctal plugs in allergic conjunctivitis—they prevent flushing of allergens and inflammatory mediators from the ocular surface 1, 2
• Avoid indiscriminate topical antibiotic use—they provide no benefit for allergic disease, induce toxicity, and contribute to antibiotic resistance 1
• Do not use vasoconstrictors chronically (>10 days) due to rebound hyperemia risk 1, 2

Follow-Up Strategy

• Reassess within 48-72 hours to confirm symptom improvement 2
• Frequency of subsequent visits depends on disease severity, etiology, and treatment response 1, 2
• Monitor patients with atopic disease for keratoconus development—adequate allergy control and preventing eye rubbing decrease ectasia progression 1, 2
• When corticosteroids are used in chronic or recurrent conjunctivitis, perform baseline and periodic IOP measurement plus pupillary dilation 1, 2

When to Refer

• Consult allergist or dermatologist for disease inadequately controlled with topical medications and oral antihistamines 1, 2
• 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
• Refer to ophthalmology for suspected VKC, AKC, or any vision-threatening complications 4, 5, 6