Allergic Conjunctivitis

Introduction

Allergic conjunctivitis is an inflammatory condition of the conjunctiva caused by exposure to allergens such as pollen, dust mites, animal dander, or mold. It is characterized by ocular itching, redness, tearing, and eyelid swelling. The disorder may be seasonal (associated with pollen exposure) or perennial (present throughout the year due to indoor allergens). Management focuses on allergen avoidance, symptomatic relief, and control of ocular inflammation.

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Treatment Options and Doses

1. Allergen Avoidance and Supportive Measures

• Avoid exposure to known allergens.

• Use cold compresses to reduce itching and swelling.

• Artificial tears or lubricating eye drops: one to two drops in each eye as needed to wash away allergens and dilute inflammatory mediators.

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2. Antihistamine Eye Drops

• Olopatadine 0.1%: one drop in each eye twice daily.

• Ketotifen 0.025%: one drop in each eye twice daily.

• Azelastine 0.05%: one drop in each eye twice daily.
  These reduce itching and redness by blocking histamine receptors.

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3. Mast Cell Stabilizers

• Nedocromil 2%: one to two drops in each eye four times daily.

• Cromolyn sodium 4%: one drop in each eye four to six times daily.
  These are more effective for long-term prevention rather than immediate relief.

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4. Dual-Action Agents (Antihistamine plus Mast Cell Stabilizer)

• Olopatadine 0.2%: one drop in each eye once daily.

• Ketotifen fumarate: one drop in each eye twice daily.
  These are commonly used first-line agents due to rapid symptom relief and preventive benefits.

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5. Oral Antihistamines (for systemic allergy symptoms)

• Cetirizine: 10 mg orally once daily (adults).

• Loratadine: 10 mg orally once daily (adults).

• Fexofenadine: 180 mg orally once daily (adults).
  Useful if allergic conjunctivitis occurs with rhinitis or other systemic symptoms.

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6. Corticosteroid Eye Drops (short-term use in severe cases only)

• Loteprednol 0.2%: one drop in each eye four times daily.

• Fluorometholone 0.1%: one drop in each eye two to four times daily.
  Reserved for severe, refractory cases due to risk of side effects such as glaucoma and cataracts.

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7. Immunotherapy (for recurrent or severe cases)

• Allergen-specific subcutaneous or sublingual immunotherapy may be considered in patients with persistent symptoms despite optimal therapy.

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Key Considerations

• Most patients respond well to topical antihistamines or dual-action agents.

• Corticosteroids should be prescribed only under ophthalmologic supervision.

• Supportive care, including allergen avoidance and lubricating eye drops, remains an important part of treatment.

• Severe forms such as vernal keratoconjunctivitis or atopic keratoconjunctivitis require specialist management.