Allergic Conjunctivitis

Introduction

Allergic conjunctivitis is inflammation of the lining of the eye (conjunctiva) due to allergy. It could occur on its own or in association with generalized atopy (asthma, eczema, spring catarrh)

Clinical features

  • Itching of the eyes with grittiness
  • May be associated with itchy ears throat, or sinusitis and
  • Brownish discolouration of the conjunctiva
  • Eyelid oedema
  • Red eyes occasionally, with watering when acute
  • Follicles on the bulbar conjunctiva especially at the limbus
  • Papillae on the tarsal conjunctiva (seen on eversion of the eyelid)
  • Phlycten in tuberculosis- appears as a yellow nodule with surrounding leash of engorged vessels

Aetiology

Exogenous allergens

  • Topical drugs: atropine, penicillin
  • Cosmetics
  • Pollen from plants and flowers (hay fever or spring catarrh)
  • House dust mite and animals

Endogenous allergens

  • Phlyctenular conjunctivitis caused by tuberculo-protein

Differential diagnoses

  • Trachoma
  • Other forms of conjunctivitis

Complications

  • Pannus formation
  • Keratoconus
  • Corneal plaques

Investigation

  • Skin sensitivity test to detect allergen

Drug treatment

Antihistaminics preparations
Antazoline sulfate 0.5%, xylometazoline
hydrochloride 0.05%

  • Adult and child over 5 years: apply 2-3 times daily

Ketotifen eye drops

  • Adult & Child 3 – 18 years: apply twice daily

Or
Olopatadine eye drops

  • Adult and Child 3 – 18 years: apply twice daily; max. duration of treatment 4 months

Corticosteroids/NSAIDS
Low dose, topical, if severe
Diclofenac sodium 0.1% eye drops

  • Adult and child: apply once daily

Phlyctenular Conjunctivitis:

  • Treat for tuberculosis using standard regimen

Caution and Contraindication to treatment

  • Avoid overuse/misuse of steroids.
  • Use only in severe cases
  • Xylometazoline is a sympathomimetic; use
    with caution in patients susceptible to angle closure glaucoma
  • Systemic absorption of antazoline and  xylometazoline may result in interactions with other drugs

Prevention

  • Avoid allergen(s) as much as possible in cases where it/they have been identified