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Scleritis and episcleritis
Episcleritis is a superficial, mild, self-limiting inflammation, whereas scleritis is a deep, very painful inflammation linked in about half of cases to systemic disease that can destroy the sclera; the distinction is made by pain, colour and the response to phenylephrine, and scleritis is treated systemically.
Why it matters in the exam
Episcleritis: a young woman with sectoral or nodular redness, mild discomfort, normal vision; the superficial vessels constrict after a phenylephrine drop and move over the sclera. It resolves on its own within weeks, sometimes recurring; treatment is lubrication and an oral NSAID if needed. Only a few patients have systemic disease. Scleritis: deep "boring" pain that wakes the patient and radiates to the temple and jaw, an eye tender to touch, a violaceous-bluish hue, and deep vessels that do not constrict with phenylephrine.
The types: diffuse anterior scleritis — the commonest; nodular; necrotising with inflammation — the most destructive, with the sclera becoming transparent and thin; and scleromalacia perforans — necrotising without inflammation and without pain, in long-standing rheumatoid arthritis. Posterior scleritis — pain, proptosis, choroidal folds and fluid, and a "T sign" on ultrasound. Associations: rheumatoid arthritis (the commonest), granulomatosis with polyangiitis (the most aggressive, ANCA), relapsing polychondritis, IBD, SLE; and infectious ones — herpes zoster and after surgery (Pseudomonas).
Work-up in scleritis: RF and anti-CCP, ANCA, ANA, syphilis serology, chest X-ray, urinalysis and kidney function (renal involvement in GPA). Treatment: an oral NSAID in non-necrotising scleritis; systemic steroids when there is no response; and in necrotising scleritis or with systemic disease — immunosuppressants (methotrexate, mycophenolate), and rituximab or cyclophosphamide in GPA. Steroid drops alone are not enough, and steroid must not be injected near the eye in necrotising scleritis. Necrotising scleritis signals active systemic disease and higher mortality. Sometimes scleritis is the first manifestation of the vasculitis, so it is the ophthalmologist who recognises it and refers to a rheumatologist. Close follow-up is needed even after the pain settles, because scleral thinning can continue silently.
Key points
- Episcleritis: superficial, mild, blanches with phenylephrine.
- Scleritis: deep pain, violaceous, does not blanch.
- About half have systemic disease — RA the commonest, GPA the most aggressive.
- Systemic treatment: NSAID, steroids, immunosuppressants.
- Necrotising = active and dangerous disease.
Summary table
| Feature | Episcleritis | Scleritis |
|---|---|---|
| Pain | Mild, discomfort | Deep, wakes from sleep, radiates |
| Colour | Bright red | Violaceous-bluish |
| Phenylephrine | Vessels constrict | No change |
| Systemic disease | Rarely | In about half; RA, GPA |
| Treatment | Lubrication, NSAID as needed | Oral NSAID, steroids, immunosuppressants |
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Sources
- AAO Basic and Clinical Science Course, Section 8: External Disease and Cornea, 2024-2025 — Episcleritis and scleritis
- AAO Basic and Clinical Science Course, Section 9: Uveitis and Ocular Inflammation, 2024-2025 — Scleritis associated with systemic disease
- Kanski's Clinical Ophthalmology, 9th edition (2020) — Episclera and sclera
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.