A 22-year-old presents with intense bilateral itching, ropy mucoid discharge, and giant papillae (> 1 mm, cobblestone appearance) on the upper tarsal conjunctiva. He has atopic dermatitis. Which type of conjunctivitis is this and what is the hallmark immunological mediator?

• A Viral conjunctivitis mediated by CD8+ T cells
• B Bacterial conjunctivitis mediated by neutrophil activation
• C Vernal keratoconjunctivitis (VKC) mediated by IgE and Th2 cytokines (IL-4, IL-5) ✓
• D Chlamydial (trachoma) conjunctivitis mediated by CD4+ Th1 cells

Explanation

Vernal keratoconjunctivitis (VKC) is a bilateral, recurrent, allergic conjunctivitis affecting young atopic males, characterised by intense pruritus, ropy mucus, and giant tarsal papillae ('cobblestones'). The pathogenesis is predominantly IgE-mediated (Type I hypersensitivity) driven by Th2 cytokines (IL-4, IL-5, IL-13) which promote mast cell degranulation (histamine, tryptase), eosinophil recruitment, and mucus hypersecretion. Treatment includes topical mast cell stabilisers (sodium cromoglicate, olopatadine) and short-course steroids.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.