Allergic Conjunctivitis

Background

• Allergic conjunctivitis is an allergic reaction in the ocular and periocular tissues manifesting as eye redness with itching and swelling due to exposure to allergens.
• Seasonal and perennial allergic conjunctivitis have no corneal involvement and result from IgE-mediated hypersensitivity reactions.
• It is usually associated with other manifestations of atopic disease, such as allergic rhinitis, asthma, urticaria, and/or atopic dermatitis.
• It usually presents with mild-to-moderate eye redness, tearing, and itching and moderate-to-severe conjunctival swelling (chemosis) in a seasonal or perennial pattern. The initial diagnosis is usually made in late childhood or young adulthood.

Evaluation

• The diagnosis is clinical and may be considered in patients with ocular redness (including conjunctival injection), ocular itching, and/or conjunctival swelling, and exposure to a known or suspected allergen.
• Laboratory testing is rarely necessary, but an evaluation of conjunctival samples may be considered for patients with severe purulent discharge, refractory disease, or a suspicion of other conditions.
• Consider a referral to an allergist if the symptoms are not well-controlled for specific allergen testing, such as in vitro tests for specific IgE antibodies, or skin prick and intradermal tests, to support the diagnosis and to guide further therapy.

Management

• Consider conservative management for mild disease, including counseling the patient to avoid allergens, irritants, and rubbing eyes, as well as the benefits of cold compresses, artificial tears, and air filtration systems.
• Medications may be used for moderate-to-severe disease or for additional symptom relief.
  • Ocular administration of mast cell stabilizers, antihistamines, or dual-action medications is the first-line therapy.
    • Consider dual-action mast cell stabilizer/antihistamine as initial therapy, such as:
      • ketotifen 0.01%-0.035% 1 drop in affected eye(s) twice daily (approximately 8-12 hours apart)
      • alcaftadine 0.25% 1 drop in affected eye(s) once daily
      • bepotastine 1.5% 1 drop in affected eye(s) twice daily
      • olopatadine 0.1% 1 drop in affected eye(s) twice daily, allowing 6 to 8 hours between doses, (or olopatadine 0.2% 1 drop in affected eye(s) once daily)
      • azelastine 0.15% 1 drop in affected eye(s) twice daily
    • Consider single-action medications if the patient is sensitive to the components of dual-action mast cell stabilizer/antihistamine, such as:
      • antihistamines - contraindicated in patients at risk for angle-closure glaucoma and options may include:
        • pheniramine maleate 0.315% / naphazoline 0.02675% (combination antihistamine and decongestant) 1-2 drops in affected eye(s) ≤ 4 times daily
        • epinastine 0.05% 1 drop in each eye twice daily, approved for use in patients ≥ 3 years old
        • emedastine difumarate 0.05% 1 drop in affected eye(s) ≤ 4 times daily, approved for use in patients ≥ 3 years old
        • levocabastine 0.1% 1 drop ≤ 4 times daily approved for use in patients ≥ 12 years old (not available in the United States)
      • mast cell stabilizer - options may include:
        • nedocromil 2% 1-2 drops in each eye twice daily, approved for use in patients ≥ 3 years old
        • cromolyn 4% 1-2 drops in each eye 4-6 times daily, approved for use in patients ≥ 2 years old
        • lodoxamide tromethamine 0.1% 1-2 drops in affected eye(s) ≤ 4 times daily, approved for use in patients ≥ 2 years old
    • Other ocular medications may be considered if the initial therapy is not effective, including topical nonsteroidal anti-inflammatory drugs (NSAIDs) alone or as an adjunct medication, ocular decongestants as an adjunct treatment, or ocular steroids for unusually severe or resistant cases or if there is a prolonged/repeated exposure to the allergens.
  • Second-generation oral antihistamines may be considered in patients with or without allergic rhinitis.
  • Allergen immunotherapy may be considered for moderate-to-severe disease if a specific allergen is identified and additional treatment is desired.
• If prominent allergic rhinitis symptoms are present, consider intranasal steroids, oral antihistamines, and/or oral montelukast (see Allergic Rhinitis for additional information).
• Consider a referral to an ophthalmologist if there are significant comorbidities, corticosteroids are needed, or new ocular symptoms develop.