What is episcleritis?

What is Episcleritis?

Episcleritis is a benign, self-limited inflammation of the episclera—the thin, vascular connective tissue layer between the conjunctiva and sclera—that presents with eye redness, mild discomfort, and typically resolves without vision-threatening complications. 1, 2, 3

Clinical Characteristics

Presentation

• Episcleritis presents with acute onset of eye redness (hyperemia of superficial vessels), lacrimation, and mild photophobia 4
• The condition causes itching, burning sensation, and simple redness, but is relatively painless or causes only mild discomfort 1, 2
• The absence of moderate-to-severe eye pain, significant photophobia, blurred vision, and diminished visual acuity are key distinguishing features that differentiate episcleritis from more serious conditions like scleritis and uveitis 1, 2

Classification

• Episcleritis is classified into two types: simple and nodular 4
• Nodular episcleritis (occurring in approximately 16% of cases) tends to be more recurrent and slightly more painful than the simple form 5, 4

Epidemiology

• The incidence is less than 1 per 1,000 people 4
• It is more common in women (69% female in one cohort) and typically affects those between 40-50 years of age, though the age range at presentation spans 18-76 years 5, 4
• Bilateral involvement occurs in approximately 32% of patients 5

Associated Conditions

Systemic Disease Associations

• Most cases of episcleritis are idiopathic, but when associated with systemic disease, inflammatory bowel disease (IBD) and rheumatoid arthritis are the most common underlying conditions 2
• Associated systemic disease is found in approximately 36% of patients 5
• Episcleritis in IBD typically correlates with bowel disease activity and often occurs during IBD flares, unlike uveitis which presents independently of intestinal disease activity 1, 2
• In rare cases (2 patients in one series), episcleritis preceded the diagnosis of systemic vasculitic diseases including Wegener granulomatosis and Cogan syndrome 5

Ocular Complications

• While generally benign, episcleritis should not be trivialized as it may be associated with ocular complications including uveitis (11.4%), corneal involvement (15%), and glaucoma (7.8%) 5
• Half of patients with episcleritis have concurrent eye disease 5

Clinical Course and Prognosis

• Most attacks resolve spontaneously within 1-3 months 4
• Approximately 28% of patients experience recurrence during follow-up 5
• Episcleritis is a self-limited disease that infrequently requires therapeutic intervention and does not typically threaten vision 3

Diagnostic Approach

Clinical Evaluation

• The diagnosis is essentially clinical 4
• Any eye pain or tenderness should raise concern for scleritis, which is a more serious condition requiring different management 4
• A careful review of systems should be performed in all patients presenting with episcleritis to identify potential systemic associations, and this should be repeated at least annually during follow-up 5
• Slit-lamp examination by an ophthalmologist is essential to confirm diagnosis and differentiate episcleritis from scleritis and uveitis 1

Referral Criteria

• Ophthalmological referral is recommended to rule out scleritis 4
• Immediate ophthalmologic referral is required if the patient has visual disturbance, blurred vision, photophobia, or moderate-to-severe eye pain, as these symptoms suggest scleritis or uveitis rather than episcleritis 1

Laboratory Workup

• Bloodwork to diagnose associated systemic rheumatological disease may be helpful 4
• A systemic work-up with blood sampling and imaging is necessary when systemic disease is suspected 6

Treatment Approach

First-Line Management

• Cold compresses and artificial tears provide symptomatic relief 4
• Topical or systemic NSAIDs or topical corticosteroids can be used for symptomatic treatment of episcleritis 1
• Approximately half of patients require treatment with oral NSAIDs 5
• Topical NSAIDs and steroids are used for persistent symptoms 4

Primary Treatment Strategy

• Treatment of the underlying bowel disease is the primary approach for episcleritis associated with IBD, as it often resolves with IBD control 1
• For episcleritis associated with other systemic conditions, immunosuppressive treatment to control the underlying autoimmune disorder may be necessary for resistant cases 4

Escalation

• Rarely, systemic steroids may be necessary for refractory cases 4

Key Clinical Pitfalls

The most critical pitfall is failing to distinguish episcleritis from scleritis, as scleritis is a painful inflammatory process that requires systemic anti-inflammatory therapy and can be sight-threatening if untreated 3, 6. The key distinguishing features are:

• Episcleritis: mild or no pain, superficial vessel hyperemia, no visual changes 2
• Scleritis: severe pain, deep vessel involvement, potential vision loss 2

Prompt initiation of therapy for scleritis can be sight-saving, making accurate differentiation essential 3.