Allergic Conjunctivitis

Acute Atopic Conjunctivitis

• A type 1 IgE-mediated allergic reaction, often seen in individuals with a family history of atopy.
• Triggers: Dust, mold, pollen.
• Symptoms: Sudden onset of itching, burning, conjunctival redness, swelling, and watery discharge.
• The reaction may be limited to the eyes or also affect the nose, skin, and lungs.
• Treatment:
  • Avoiding allergens when possible.
  • Medications may be required when avoidance is not feasible.
  • Some medications take at least two weeks to show effects.
  • Chronic allergic conjunctivitis is diagnosed when symptoms persist for more than four weeks.
  • Patients should be monitored for weakened immune response and potential infections.

Allergic Dermato-Conjunctivitis

• A type 4 allergic reaction caused by contact allergy affecting the eyelids and conjunctiva.
• Triggers:
  • Previous exposure to allergens such as clothing, jewelry, plastics.
  • Certain medications, including idoxuridine, atropine, and thimerosal.
• Symptoms:
  • Severe itching with mucopurulent discharge.
  • Development of papillary structures on the conjunctiva.
  • Eczematous dermatitis on the lower eyelids and outer parts of the eyelids.
  • In chronic cases, blockage of tear ducts, leading to excessive tearing.
  • The eyelid skin may appear thin and parchment-like.
  • Corneal damage with small punctate lesions.

Vernal Conjunctivitis

• Chronic, recurrent conjunctivitis primarily affecting children.
• Seasonal, occurring mostly in spring and summer, with reduced incidence in cooler months.
• More common in males (2:1 ratio), typically between the ages of 5 and 20.
• Family history of atopy is common.
• Symptoms:
  • Severe itching, light sensitivity, burning sensation, tearing, mild eyelid drooping, and mucus-like discharge.
• Three clinical forms:
  1. Palpebral form – Large, cobblestone-like papillary structures on the upper eyelid conjunctiva.
  2. Limbal form – Small, gelatinous nodules at the junction of the cornea and conjunctiva (Horner-Trantas dots).
  3. Mixed form – A combination of both.
• Corneal involvement occurs in 50% of cases:
  • Early stage: Small punctate epithelial defects.
  • Later stage: Formation of pannus (vascular and fibrous tissue growth).
  • Chronic cases may develop corneal ulcers and deep corneal opacities.
• Treatment:
  • Long-term management with 4% cromolyn sodium to control chronic symptoms.
  • Corticosteroid eye drops may be used in acute cases, considering potential side effects.