Episcleritis is self-limiting, recurring, usually idiopathic inflammation of the episcleral tissue that does not threaten vision. Symptoms are a localized area of hyperemia of the globe, irritation, and lacrimation. Diagnosis is clinical. Treatment is symptomatic.
The episclera is a thin vascular membrane between the conjunctiva and the sclera.
Episcleritis occurs in young adults, more commonly among women. It is usually idiopathic; it can be associated with connective tissue diseases and rarely with serious systemic diseases (present in about 15% of patients). (See also Overview of Conjunctival and Scleral Disorders.)
Mild irritation occurs. Additionally, a bright red patch is present just under the bulbar conjunctiva (simple episcleritis). A hyperemic, edematous, raised nodule (nodular episcleritis) may also be present. The palpebral conjunctiva is normal.
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
Episcleritis is distinguished from conjunctivitis by hyperemia localized to a limited area of the globe, much less lacrimation and no discharge. It is distinguished from scleritis by lack of photophobia and lack of severe pain.
The condition is self-limited. If the review of systems does not suggest an underlying cause, unless the episode recurs, then a diagnostic assessment for systemic disorders is not routinely warranted.