What is the recommended management for allergic conjunctivitis?

Management of Allergic Conjunctivitis

Start with dual-action topical antihistamine/mast cell stabilizer eye drops (olopatadine, ketotifen, azelastine, or epinastine) as first-line therapy, combined with refrigerated preservative-free artificial tears and allergen avoidance measures. 1, 2, 3

First-Line Treatment Approach

Topical Pharmacotherapy

• Prescribe dual-action agents as the cornerstone of treatment because they provide both immediate symptom relief through antihistamine action and prevent future episodes through mast cell stabilization 1, 3
• Olopatadine 0.1% offers rapid onset within 30 minutes with 8-hour duration of action 1
• These agents can be refrigerated for additional cooling relief upon instillation 3

Essential Adjunctive Measures

• Use refrigerated preservative-free artificial tears four times daily to dilute allergens and inflammatory mediators on the ocular surface 1, 2, 3
• Implement allergen avoidance: wear sunglasses as a physical barrier against airborne allergens, use hypoallergenic bedding, wash clothes frequently, and shower before bedtime 1, 2, 3
• Apply cold compresses to reduce inflammation and provide symptomatic relief 2
• Counsel patients to avoid eye rubbing, which can worsen symptoms and increase risk of keratoconus, especially in atopic patients 2, 3

Role of Oral Antihistamines

• Add second-generation oral antihistamines only for systemic allergic symptoms (such as urticaria or rhinitis) 1
• Do not rely on oral antihistamines as primary treatment because they may worsen dry eye syndrome and impair the tear film's protective barrier 1, 3

Critical Pitfalls to Avoid

• Never use punctal plugs in allergic conjunctivitis because they prevent flushing of allergens and inflammatory mediators from the ocular surface 4, 2, 3
• Avoid prolonged vasoconstrictor use (beyond 10 days) as this causes rebound hyperemia (conjunctivitis medicamentosa) 1, 3
• Do not prescribe topical antibiotics as they can induce toxicity and are not indicated for allergic conjunctivitis 3

Escalation for Inadequate Response

When to Add Corticosteroids

• If symptoms do not improve within 48 hours on dual-action drops, add a brief 1-2 week course of loteprednol etabonate 1, 3
• Loteprednol etabonate is the preferred topical corticosteroid due to its low side-effect profile, with only 1% incidence of clinically significant IOP elevation (≥10 mmHg) compared to 6% with prednisolone acetate 1% 5
• Perform baseline and periodic IOP measurement plus pupillary dilation to evaluate for glaucoma and cataract when using any corticosteroid 4, 2, 3

Severe or Refractory Cases

• Consider topical cyclosporine 0.05% or tacrolimus for severe cases unresponsive to the above treatments 4, 2, 3
• Topical cyclosporine 2% has demonstrated reduction in signs and symptoms after two weeks in vernal keratoconjunctivitis (VKC), and the commercially available 0.05% formulation is effective with more frequent dosing 4
• Cyclosporine may allow for reduced use of topical steroids 4

Special Considerations for Vernal/Atopic Keratoconjunctivitis

Acute Exacerbations

• Topical corticosteroids are usually necessary to control severe symptoms and signs in VKC/atopic keratoconjunctivitis 4
• Inform patients about potential complications of corticosteroid therapy and employ strategies to minimize corticosteroid use 4

Severe Sight-Threatening Disease

• For severe atopic keratoconjunctivitis unresponsive to topical therapy, consider supratarsal injection of corticosteroid 4, 2
• Systemic immunosuppression is rarely warranted but options include montelukast, interferons, and oral T-cell inhibitors such as cyclosporine and tacrolimus 4
• 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+) 4
• Be aware that tacrolimus or pimecrolimus may increase susceptibility to herpes simplex keratitis 4

Follow-Up Strategy

• Reassess in 48-72 hours to confirm symptom improvement 1
• Arrange face-to-face ophthalmology evaluation if no improvement is seen to rule out vernal or atopic keratoconjunctivitis 1
• Frequency of follow-up visits is based on disease severity, etiology, and treatment 4
• 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 4

When to Refer

• Consult an allergist or dermatologist for patients with disease that cannot be adequately controlled with topical medications and oral antihistamines 4, 2
• Allergen-specific immunotherapy (subcutaneous or sublingual) is useful for achieving hyposensitization, though usage may be limited by expense, long-term patient commitment, and risk of anaphylaxis 4