OP5.1 | Episcleritis — Summary & Reflection

KEY TAKEAWAYS

Episcleritis and scleritis both present as red eye but occupy opposite ends of the severity spectrum. Episcleritis is a superficial inflammation of the episcleral tissue characterised by sectoral bright-red injection, mild discomfort, preserved vision, and complete blanching with phenylephrine 2.5%. It is almost always self-limiting, managed conservatively with lubricants and topical NSAIDs, and rarely associated with systemic disease. Scleritis is a deep scleral inflammation characterised by severe boring nocturnal pain, violaceous non-blanching injection, tenderness on palpation, and frequent systemic associations (RA, GPA, relapsing polychondritis). The Watson & Hayreh classification identifies five anterior subtypes — diffuse, nodular, necrotising with inflammation, and necrotising without inflammation (scleromalacia perforans) — plus posterior scleritis. Scleromalacia perforans is paradoxically painless (occurring in severe long-standing RA) and represents a diagnostic trap. The phenylephrine 2.5% blanching test is the pivotal bedside differentiator. Management of scleritis requires systemic NSAIDs, corticosteroids, or immunosuppression depending on severity, and joint rheumatology management for all patients with confirmed systemic disease. Untreated scleritis risks scleral thinning, corneal melt, globe perforation, and permanent vision loss.

REFLECT

Consider a patient you might see in your future practice: a 50-year-old woman with known rheumatoid arthritis presents to the eye OPD with a three-day history of a red eye and what she describes as 'mild soreness.' You notice the eye is not dramatically red, and she seems tolerant of the discomfort. Outline the clinical features you would specifically look for on examination to determine whether this is episcleritis, a scleritis flare, or something unrelated to her RA. What single examination finding would most definitively guide your management decision? What would prompt you to initiate a systemic work-up, and what would reassure you that no further investigation is needed? Reflect on how the presence of rheumatoid arthritis changes your index of suspicion compared to a healthy 28-year-old presenting with the same complaint.