Can episcleritis be caused by a viral infection?

Is Episcleritis Sometimes Viral?

No, episcleritis is not typically caused by viral infections—most cases are idiopathic, and when associated with systemic disease, the primary causes are autoimmune conditions like inflammatory bowel disease and rheumatoid arthritis, not viral pathogens. 1, 2, 3

Etiology of Episcleritis

Primary Causes

• Most cases (majority) are idiopathic with no identifiable underlying cause 2, 3, 4
• When systemic disease is present (less than one-third of cases), the most common associations are:
  • Inflammatory bowel disease (4-12% of IBD patients develop episcleritis) 1, 3, 5
  • Rheumatoid arthritis and other inflammatory rheumatisms 3, 6
  • Systemic vasculitides 6

Pathophysiology

• Episcleritis represents immune-mediated inflammation involving activation and infiltration of both innate and adaptive immune cells into the episcleral tissue 1, 5
• The condition is not an infectious process but rather an inflammatory response, often correlating with bowel disease activity in IBD patients 3, 5

Important Clinical Distinction

Viral Infections Cause Different Ocular Conditions

While the provided evidence discusses viral causes of encephalitis (VZV, HSV, enteroviruses) 1, these are neurological conditions, not episcleritis. Infectious scleritis (the deeper, more severe condition) can rarely be of herpetic origin (VZV and HSV), but this represents only 8% of scleritis cases—not episcleritis 6

Key Differentiating Features

• Episcleritis presents with mild or no pain, superficial vessel hyperemia, preserved vision, itching, and burning 2, 3, 5
• It is self-limited, resolving within 1-3 months in most cases 4, 7
• The benign nature and typical presentation pattern are inconsistent with active viral infection 4, 7, 8

Clinical Pitfalls to Avoid

• Do not confuse episcleritis with infectious scleritis, which can have viral (herpetic) causes but is a much more severe condition with deep vessel involvement and severe pain 6
• Do not assume all red eyes with systemic symptoms are infectious—the association with IBD flares and autoimmune conditions is far more common than viral causes 1, 3, 5
• Always rule out scleritis if severe pain, photophobia, or visual disturbance are present, as this requires urgent ophthalmologic evaluation and aggressive treatment 2, 5, 8