allergic conjunctivitis

Last reviewed 01/2018

The patient with allergic conjunctivitis presents with:

• intense itching
• conjunctival oedema
• apparent enophthalmos - the eyes sink into the surrounding oedematous tissue
• hyperaemia may be relatively mild
• allergic eye disease is generally seasonal

Major types of allergic conjunctivitis include:

• atopic
• vernal
• pseudo-vernal
• phlyctenular

Management principles:

• avoidance of allergen if known
• pharmaceutical management options include:
  • topical mast cell stabilisers
    • for example sodium cromoglycate
      • use throughout a period of allergen exposure
      • newer agents (e.g. lodoxamide and nedocromil) may be effective in those with an inadequate response to sodium cromoglicate
        
        
  • topical antihistamines may be useful
    • azelastine may also have additional mast cell stabilising properties
    • not a therapeutic option that is appropriate for prolonged use (no longer than six weeks)
    • not an appropriate treatment option in contact dermatoconjunctivitis
      
      
  • oral antihistamines such as loratadine or chlorphenamine may be used
    • especially useful when there is associated allergic rhinitis
    • can cause drowsiness, especially the older compounds such as chlorphenamine - patients need to be cautioned regarding this
      
      
  • in general, corticosteroid containing ointments or drops should be avoided unless the prescriber is able to monitor accurately for adverse effects (1) e.g. glaucoma, cataract - and also should only be used if certain of the diagnosis of allergic conjunctivitis
    
    
  • diclofenac eye drops - these are licensed for seasonal allergic conjunctivitis
    
    
  • oral corticosteroid therapy
    • a short (five-day) course may be used in severe cases where there is no doubt about the diagnosis
    • ophthalmologists may use oral steroids in severe cases of allergic conjunctivitis

Reference:

• (1) Prescribers' Journal (2000), 40 (2), 130-137.
• (2) Azari AA, Barney NP; Conjunctivitis: a systematic review of diagnosis and treatment. JAMA. 2013 Oct 23;310(16):1721-9.