Episcleritis

Episcleritis is inflammation of the episclera - the thin layer of tissue that sits between the surface conjunctiva and the deeper sclera. It is one of the most common causes of a sudden, sectoral red eye in adults, and despite the dramatic appearance it is usually mild, often self-limited, and rarely associated with significant vision loss. The most important task in evaluating episcleritis is to distinguish it from the deeper, far more serious scleritis and from other causes of red eye.

Episcleritis vs. Scleritis vs. Conjunctivitis

The three conditions are often confused on first inspection but feel and look different on closer examination:

The phenylephrine test is one useful bedside maneuver. A drop of 2.5% phenylephrine (or 10% in some practices) constricts the more superficial episcleral vessels - making the redness fade - but has less effect on deeper scleral vessels. Blanching supports episcleritis; persistent deep redness raises concern for scleritis and must be interpreted with pain, tenderness, slit-lamp findings, and clinical judgment.

Types

Simple Episcleritis (Most Common)

Diffuse or sectoral redness of the episclera with mild discomfort. Comes on over hours, peaks within a day or two, and resolves spontaneously over 1-2 weeks. Often unilateral, but recurrences may alternate sides.

Nodular Episcleritis

A small, raised, tender nodule on the episclera, typically with surrounding redness. The nodule can be moved with a cotton-tipped applicator over the underlying sclera, distinguishing it from a fixed scleritis nodule. Tends to take longer to resolve than simple episcleritis (3-6 weeks).

Symptoms

• Sudden onset of localized red eye, often described as a "patch of redness"
• Mild discomfort - a hot, gritty, or "achy" feeling rather than severe pain
• Tearing
• Mild photophobia in some cases
• Vision is typically unaffected
• Often unilateral, with recurrences that may alternate between eyes
• Patients usually feel well systemically

Causes

Idiopathic (most common)

The majority of episcleritis cases have no identifiable cause and are presumed to be a transient inflammatory response to non-specific triggers.

Autoimmune and Connective Tissue Diseases

A minority of cases - particularly recurrent or bilateral - are associated with:

• Rheumatoid arthritis
• Inflammatory bowel disease (ulcerative colitis, Crohn's)
• Spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis)
• Systemic lupus erythematosus
• Granulomatosis with polyangiitis and other vasculitides (less common in episcleritis than in scleritis)
• Relapsing polychondritis

Infectious

Less common as a cause of episcleritis than of scleritis, but possible:

• Herpes simplex and herpes zoster (especially after herpes zoster ophthalmicus)
• Lyme disease in endemic regions
• Syphilis, tuberculosis in selected populations

Other Triggers

• Recent viral upper respiratory infection
• Allergic exposure
• Following ocular surgery or trauma in the area

Diagnosis

Clinical Examination

The diagnosis is clinical, based on a slit lamp examination:

• Vessel level - superficial episcleral, lifted slightly off the sclera by the inflammation
• Color - bright red, often sectoral
• Mobility - episcleral tissue can usually be moved over the underlying sclera with a cotton-tipped applicator
• Phenylephrine test (2.5% or 10%) - episcleritis blanches; scleritis does not
• Tenderness - minimal in episcleritis, marked in scleritis
• Anterior chamber - clear in episcleritis (no cells, no keratic precipitates)

When to Order a Systemic Workup

Most first episodes of typical simple episcleritis do not require workup beyond the eye examination. A workup is appropriate when:

• The patient has recurrent episcleritis (more than 2-3 episodes)
• Both eyes are involved
• Episodes alternate between eyes
• There are systemic symptoms (joint pain, rash, weight loss, fevers)
• The pain or appearance is unusually severe and scleritis is in the differential

The workup, when ordered, is similar to scleritis though usually less extensive: blood tests including CBC, ESR, CRP, ANA, rheumatoid factor, and selected ANCA testing; serology for syphilis and Lyme as indicated; HLA-B27 in suspected spondyloarthropathy.

Treatment

Conservative Measures (often sufficient)

• Cool compresses for symptom relief
• Preservative-free artificial tears four to six times daily
• Avoidance of irritants (smoke, dust, allergens)
• Reassurance - most cases resolve without medication

Topical Therapy

• Topical NSAID drops are sometimes prescribed but have not shown benefit over artificial tears in the available randomized data and are not first-line
• Mild topical corticosteroids (fluorometholone, loteprednol) - reserved for more bothersome cases or nodular episcleritis. Use the lowest effective dose for the shortest time to avoid steroid-induced glaucoma and cataract.

Systemic Therapy

Rarely needed for episcleritis itself, but considered for:

• Severe, frequent recurrences unresponsive to topical therapy
• Systemic disease that requires its own treatment

Oral NSAIDs (ibuprofen, naproxen, indomethacin) are the most common systemic agents used for episcleritis. Oral steroids and immunosuppressants are usually reserved for cases that are difficult to distinguish from mild scleritis or that have a clear underlying systemic disease driving the eye involvement.

What Not to Do

• Avoid prolonged use of decongestant ("redness-reducing") drops - they cause rebound redness and mask the underlying problem
• Avoid casual use of stronger topical steroids without monitoring intraocular pressure

Prognosis

The visual prognosis is excellent. Most episodes resolve fully without sequelae, even without treatment. Recurrences are common - especially in the first year - and tend to become less frequent over time. Patients with recurrent episcleritis associated with a systemic disease tend to have better control of their eye flares when the systemic disease is well-treated.

Complications are uncommon but include:

• Mild dry eye symptoms during a flare
• Steroid-related glaucoma or cataract from prolonged topical steroid use (an iatrogenic complication)
• Progression to scleritis is possible but unusual; patients with this transition typically have a systemic vasculitis driving both

Frequently Asked Questions

How can I tell if it is episcleritis or scleritis?

Episcleritis is uncomfortable but rarely severely painful, the redness is bright and superficial, and the eye blanches when a doctor uses a phenylephrine drop. Scleritis is deeply painful (often waking patients from sleep), the redness has a violaceous tint, and the eye does not blanch with phenylephrine. The distinction is made at a slit lamp examination.

Can episcleritis come back?

Yes. Recurrences are common in the first year, particularly with simple episcleritis. Recurrences alone do not necessarily mean an underlying disease, but a pattern of repeated or alternating episodes is a reason to look for one.

Do I need to see a specialist for episcleritis?

A first episode of mild episcleritis can often be managed in primary eye care or general practice. Recurrent or severe episodes, or any uncertainty about whether it is scleritis, should be evaluated by an ophthalmologist.

Will my vision be affected?

Vision is typically unaffected. Episcleritis is a surface inflammation that does not involve the cornea or the inside of the eye. Vision changes during a flare-up suggest the diagnosis may be something else, such as scleritis with associated keratitis or uveitis.

Is episcleritis contagious?

No. Unlike infectious conjunctivitis, episcleritis is not transmitted from person to person.

References