What are the clinical differences and treatment approaches for scleritis vs episcleritis?

Clinical Differences and Treatment of Scleritis vs Episcleritis

Scleritis requires urgent ophthalmology referral and systemic treatment with corticosteroids and immunosuppressants, while episcleritis is a benign, self-limited condition that responds to topical NSAIDs or corticosteroids alone. 1

Key Clinical Distinctions

Pain Severity

• Episcleritis presents with mild or no pain, often described as itching and burning, whereas scleritis causes moderate to severe, deep ocular pain that is the hallmark distinguishing feature 1, 2
• The presence of severe pain should immediately raise concern for scleritis rather than episcleritis 3, 4

Visual Changes

• Episcleritis does not cause visual disturbances or vision loss 1, 5
• Scleritis frequently causes photophobia, blurred vision, and can progress to permanent visual deficits if untreated 1, 5
• Visual acuity decreased in 15.9% of scleritis patients but in zero episcleritis patients in one large series 5

Appearance and Depth of Inflammation

• Episcleritis shows superficial hyperemia of the conjunctiva and episclera with a bright red appearance 1
• Scleritis demonstrates deep vessel involvement with a "turky" or bluish-red discoloration of the sclera 4, 6
• Slit-lamp examination is essential to differentiate the depth of inflammatory cell infiltration 1

Ocular Complications

• Episcleritis has minimal complications (13.5% complication rate) and is self-limited 5
• Scleritis carries high complication risk (58.8% complication rate) including uveitis, glaucoma, cataract, retinal detachment, and vision loss 7, 5
• Necrotizing scleritis has the worst prognosis with 91.7% complication rate 5

Treatment Approach for Episcleritis

First-Line Management

• Topical NSAIDs or topical corticosteroids are the mainstay of treatment 1, 3
• The condition may self-resolve without treatment in many cases 1
• Treatment of underlying systemic disease (if present) often leads to resolution 1, 3

When to Escalate

• Oral NSAIDs should be added for persistent or recurrent symptoms not responding to topical therapy 3
• Use the minimum effective dose for the shortest duration due to cardiovascular and gastrointestinal risks 3
• Only 16.7% of episcleritis patients require more than topical therapy 5

Important Caveats

• Do not use systemic immunosuppression for simple episcleritis—topical therapy is sufficient 3
• Ophthalmology referral is not required if diagnosis is clear and symptoms are mild 3
• Reassess diagnosis if no improvement after 2-4 weeks of topical therapy 3

Treatment Approach for Scleritis

Immediate Actions

• Urgent ophthalmology referral is mandatory for slit-lamp examination and classification of scleritis subtype 1, 4
• Scleritis is a vision-threatening emergency requiring immediate systemic treatment 4, 6

Non-Necrotizing Anterior Scleritis

• Start with oral NSAIDs as initial therapy 4, 8
• Add oral corticosteroids (prednisone) if NSAIDs fail after 1-2 weeks or if disease is moderate to severe at presentation 4, 8
• Taper prednisone over 6-8 weeks based on clinical response 4
• 30.4% of scleritis patients require NSAIDs, 31.9% require oral prednisone, and 26.1% require systemic immunosuppressants 5

Necrotizing or Refractory Scleritis

• Immediate high-dose systemic corticosteroids (oral prednisone or IV methylprednisolone for severe cases) plus concurrent disease-modifying antirheumatic drugs (DMARDs) 4, 8
• Anti-TNF biologics (infliximab or adalimumab) are recommended when conventional DMARDs fail or for severe necrotizing disease 1, 4, 8
• Rituximab may be effective in refractory cases 8
• 90% of necrotizing scleritis patients require oral corticosteroids or immunosuppressants 5

Monitoring Requirements

• Close coordination between ophthalmology and rheumatology/internal medicine is essential 4, 8
• Follow-up every 1-2 weeks during acute phase, then monthly during maintenance therapy 4
• Scleritis may be the first indicator of underlying rheumatoid vasculitis 8

Critical Pitfalls to Avoid

• Never mistake scleritis for episcleritis—severe pain mandates urgent ophthalmology evaluation 3, 4
• Never delay ophthalmology referral when scleritis is suspected—rapid progression to vision loss can occur 4
• Never treat scleritis with topical therapy alone—systemic treatment is obligatory to prevent irreversible visual loss and reduce mortality risk 6
• Never ignore underlying systemic disease—up to 50% of scleritis cases are associated with conditions like rheumatoid arthritis or granulomatosis with polyangiitis 6