Episcleritis
BASICS
DESCRIPTION
- Inflammation and irritation of the episclera, thin vascular connective tissue between conjunctiva and sclera.
- Typically benign and self-limited, resolves within 3 weeks without treatment.
- Symptoms may be relieved with topical lubricants and/or corticosteroids.
TYPES
- Simple episcleritis: diffuse scleral involvement, more common.
- Nodular episcleritis: focal area(s) of involvement, less common.
EPIDEMIOLOGY
- Slight female predominance (~60-65%).
- Can occur at any age; peak incidence 40s-50s.
- Incidence ~20-50 cases per 100,000 person-years.
- Prevalence ~53 cases per 100,000 person-years in recent study.
ETIOLOGY AND PATHOPHYSIOLOGY
- Usually idiopathic; ~1/3 have systemic autoimmune disease.
- Pathophysiology:
- Nonimmune: dry eye syndrome, vasodilation, edema, lymphocytic infiltration.
- Immune: systemic vasculitis, rheumatologic disease.
COMMONLY ASSOCIATED CONDITIONS
- Usually isolated, but can be early sign of systemic disease such as:
- Rheumatoid arthritis
- Vasculitis
- Inflammatory bowel disease
- Ankylosing spondylitis
- Psoriatic arthritis
- Systemic lupus erythematosus
- Gout
- Herpes zoster
- Hypersensitivity disorders
- Rosacea
- Contact dermatitis
- Penicillin sensitivity
- Erythema multiforme
- Can be ocular manifestation of infectious conditions.
DIAGNOSIS
CLINICAL DIAGNOSIS
- Episcleritis diagnosed clinically.
PHENYLEPHRINE TEST
- 10% phenylephrine eye drops used to distinguish from scleritis.
- Blanching = episcleritis (superficial vessels).
- No blanching = scleritis (deeper vessels).
HISTORY
- Assess for causative factors, recurrence, systemic disease.
- Pain: usually absent or mild, localized.
- Mild tearing possible.
PHYSICAL EXAM
- Visual acuity usually normal; decreased vision suggests other diagnosis (e.g., scleritis).
- Pink or purplish sclera due to superficial episcleral vascular dilation.
- Focal hyperemia and episcleral edema (diffuse in simple, focal in nodular).
- Pupils equal, reactive.
- Tenderness over involved area may be present but usually absent.
- Episcleral hyperemia blanches with phenylephrine.
Alert: Recurrent, diagnostic uncertainty, or worsening symptoms require ophthalmology referral.
DIFFERENTIAL DIAGNOSIS
- Scleritis
- Bacterial/viral conjunctivitis
- Uveitis
- Herpes (ulcerative) keratitis
- Superficial keratitis
- Ocular hypertension
DIAGNOSTIC TESTS
- Extensive labs usually unnecessary unless suspicion for scleritis or refractory disease.
- Possible labs: CBC, CMP, ESR, CRP, RF, ANA, ANCA, complements, RPR, HLA B27, ACE, urinalysis.
- TB screening (PPD or T-SPOT).
- Imaging: chest X-ray, chest CT if systemic disease suspected.
TREATMENT
GENERAL
- Simple episcleritis self-limited (up to 21 days).
- Nodular form may be prolonged, painful.
MEDICATION
First Line
- Topical lubricants/artificial tears.
Second Line
- Topical NSAIDs (Diclofenac 0.1%, Ketorolac 0.5%).
- Topical corticosteroids (Fluorometholone, Prednisolone 0.5-1%).
- Oral NSAIDs or COX inhibitors for refractory cases.
ISSUES FOR REFERRAL
- Ophthalmology referral if:
- Corticosteroid eye drops needed
- Recurrent episodes
- Diagnostic uncertainty
- Worsening symptoms
- Suspected progression to scleritis
ADDITIONAL THERAPIES
- Topical NSAIDs not superior to artificial tears.
- Antiviral therapy if viral cause identified.
ONGOING CARE
FOLLOW-UP
- Usually none needed; self-limited condition.
PROGNOSIS
- Full recovery typical without complications.
COMPLICATIONS
- Rare.
- Anterior uveitis (4-16%).
- Decreased vision (0-4%).
- Ocular hypertension (0-3.5%).
REFERENCES
- Diaz JD, Sobol EK, Gritz DC. Treatment and management of scleral disorders. Surv Ophthalmol. 2016;61(6):702-717.
- Miller JR, Hanumunthadu D. Inflammatory eye disease: clinical overview. Clin Med (Lond). 2022;22(2):100-103.
CODES
- ICD10 H15.109 Unspecified episcleritis, unspecified eye
- ICD10 H15.129 Nodular episcleritis, unspecified eye
- ICD10 H15.102 Unspecified episcleritis, left eye
CLINICAL PEARLS
- Episcleritis is inflammation of the thin vascular layer between conjunctiva and sclera.
- Usually benign, self-limited, resolving within 3 weeks.
- Mild or no pain; vision usually unaffected.
- Treatment aims at symptom relief pending spontaneous resolution.
- Differentiate from scleritis using phenylephrine test.
- Referral required if recurrent, worsening, or uncertain diagnosis.
- Complications uncommon but include anterior uveitis and ocular hypertension.