Scleritis and Episcleritis: How to Tell Them Apart
Last updated: November 2026
Both cause a red eye, but episcleritis is a nuisance and scleritis can destroy the eye and signal a serious systemic disease. Pain, the depth of the injected vessels and the response to phenylephrine separate them in most cases.
Side by side
| Feature | Episcleritis | Scleritis |
|---|---|---|
| Pain | Mild discomfort | Severe, boring pain, worse at night, radiating to the face; wakes the patient |
| Colour | Bright red, salmon pink | Deep violaceous (bluish-red) |
| Vessels | Superficial, move over the sclera | Deep, do not move; scleral oedema |
| Phenylephrine 2.5–10% | Vessels blanch | Deep vessels do not blanch |
| Tenderness | Mild | Marked |
| Vision | Normal | May fall (keratitis, uveitis, posterior involvement) |
| Systemic disease | Uncommon | In about half: rheumatoid arthritis, GPA, relapsing polychondritis, IBD, SLE, infection |
Types of scleritis (Watson)
- Anterior diffuse: the commonest and most benign.
- Anterior nodular: an immobile, tender nodule.
- Necrotising with inflammation: the most destructive; avascular white patches; strongly associated with systemic vasculitis.
- Necrotising without inflammation (scleromalacia perforans): painless thinning in long-standing rheumatoid arthritis.
- Posterior: pain, proptosis, choroidal folds, exudative detachment; B-scan shows fluid in Tenon space (the T-sign).
Work-up for scleritis
- Full blood count, ESR, CRP, kidney function and urinalysis (vasculitis).
- Rheumatoid factor, anti-CCP, ANA, ANCA (PR3 and MPO).
- Syphilis serology, TB testing, chest X-ray; consider infectious scleritis after surgery or trauma.
- B-scan for posterior scleritis.
Treatment
| Condition | Treatment |
|---|---|
| Episcleritis | Reassurance, cold compresses, lubricants; short course of topical steroid or oral NSAID if troublesome |
| Non-necrotising scleritis | Oral NSAIDs first (for example flurbiprofen or indomethacin), with gastric protection |
| Unresponsive, necrotising or posterior scleritis | Oral or IV steroids with an immunosuppressant (methotrexate, mycophenolate) or biologics (rituximab for ANCA vasculitis, anti-TNF), shared with rheumatology |
| Infectious scleritis | Culture and targeted antimicrobials; avoid steroids until infection is controlled |
Periocular steroid injections are avoided in necrotising scleritis because of the risk of perforation.
Where residents slip
- Treating scleritis with topical steroids alone.
- Missing GPA: always test urine and ANCA.
- Injecting periocular steroid in necrotising disease.
- Forgetting posterior scleritis in a painful eye with choroidal folds.
Test yourself: flip cards
Related: Uveitis Made Easy: SUN Terms, Patterns and Work-up, Red Eye, Uveitis Work-up: A Targeted Approach for Residents.
Key sources
- Watson PG, Hayreh SS. Scleritis and episcleritis. Br J Ophthalmol. 1976;60:163-191
- Sainz de la Maza M, et al. Clinical characteristics of a large cohort of patients with scleritis and episcleritis. Ophthalmology. 2012;119:43-50
📘 Want more exam-ready material? See Most Commons in Ophthalmology on Kindle, or browse all my books.
Looking for an eye specialist in Ahmedabad? Learn about our Eye Department or book a consultation with Dr. Dhaval Patel.