OP3.4 | Allergic Conjunctivitis and Vernal Catarrh — Summary & Reflection

KEY TAKEAWAYS

Allergic conjunctivitis is a spectrum: SAC/PAC (seasonal/perennial, IgE-mediated Type I, not sight-threatening), VKC (vernal keratoconjunctivitis — young males, hot climates, mixed Type I+IV hypersensitivity, potentially sight-threatening), AKC (adults with atopic dermatitis), GPC (contact-lens mechanical irritation). VKC palpebral form: giant cobblestone papillae >1 mm on upper tarsal conjunctiva; limbal form: Trantas dots (eosinophils at upper limbus). Pathognomonic signs: giant papillae >1 mm, Trantas dots, Herbert's pits (from prior trachoma — distinguish). Shield ulcer = superficial oval corneal ulcer, upper-central cornea; caused by eosinophil MBP from giant papillae; NOT infectious; treated with topical steroids + lubricants (not antibiotics alone). Cytological hallmark: eosinophils on conjunctival scraping. Management: allergen avoidance → topical mast-cell stabilisers (sodium cromoglicate/lodoxamide) → dual-action antihistamines (olopatadine) → short-course topical steroids (fluorometholone/prednisolone, monitor IOP) → cyclosporine for steroid-dependent disease. Steroid trap: IOP monitoring mandatory during topical steroid use; prolonged use → steroid glaucoma + posterior subcapsular cataract.

REFLECT

Allergic conjunctivitis significantly impairs quality of life — students, particularly in hot climates, may miss school or examinations during VKC flares. Reflect on how you would counsel the parents of a 10-year-old boy newly diagnosed with VKC. What are the three most important messages to convey about prognosis, trigger avoidance, and the risk of eye rubbing? How would you explain the need for IOP monitoring when prescribing a steroid eye drop to a parent who is worried about giving a 'steroid' to their child? Write a two-minute counselling script in your reflective journal.