Causes and Clinical Characteristics of Unilateral Episcleritis

Introduction to Unilateral Episcleritis

Most cases of unilateral episcleritis are idiopathic, but when associated with systemic disease, inflammatory bowel disease and rheumatoid arthritis are the most common underlying conditions 1, 2

Episcleritis is one of the most common ocular manifestations of IBD, with reported incidence ranging from 4-12% of IBD patients 2
Episcleritis in IBD typically correlates with bowel disease activity, unlike uveitis which can occur independently of intestinal symptoms 2
The condition affects both ulcerative colitis and Crohn's disease patients, presenting with hyperemic sclera and conjunctiva, itching, and burning sensation 1, 2

The key distinguishing feature is that episcleritis presents with mild or no pain, hyperemia of superficial vessels, and no visual changes, whereas scleritis causes severe pain, deep vessel involvement, and potential vision loss 2, 3, 4
Episcleritis is relatively painless with simple redness, itching, and burning 2
The absence of moderate-to-severe eye pain, photophobia, blurred vision, and diminished visual acuity differentiates episcleritis from the more serious conditions of scleritis and uveitis 2, 4