BASICS

DESCRIPTION

• Uncommon, usually unilateral, affects conjunctiva and/or cornea

• Seen more commonly in children and young adults

• Due to type IV hypersensitivity reaction to microbial agents

• Pinkish-white nodule at limbus involving conjunctiva and/or cornea

EPIDEMIOLOGY

Incidence

60–70% female

Prevalence

Unknown

RISK FACTORS

Blepharitis

Genetics

None

GENERAL PREVENTION

Treat blepharitis: lid scrubs

PATHOPHYSIOLOGY

Delayed type hypersensitivity to bacterial antigen

ETIOLOGY

• Staphylococcal infection

• Tuberculosis

• Chlamydia, Candida, Coccidioides

COMMONLY ASSOCIATED CONDITIONS

Blepharitis

DIAGNOSIS

HISTORY

• Pain, photophobia, tearing, foreign body sensation, redness

– If cornea involved, symptoms more severe

PHYSICAL EXAM

• Conjunctival phlycten: small, round, elevated, yellow to white nodule near limbus

• Corneal phlycten: starts at limbus, can extend onto cornea, may have associated epithelial defect

DIAGNOSTIC TESTS & INTERPRETATION

Lab

Chest X-ray (CXR), purified protein derivative (PPD) if suspicious of tuberculosis (1)[C]

Imaging

CXR, PPD in suspicious cases

Diagnostic Procedures/Other

Corneal cultures if infectious keratitis suspected (1)[C]

Pathological Findings

Histopathology shows that nodules are composed of lymphocytes, histiocytes, and plasma cells.

DIFFERENTIAL DIAGNOSIS

• Rosacea keratitis

• Inflamed pinguecula

• Limbal herpes keratitis

• Microbial keratitis

• Nodular episcleritis

TREATMENT

MEDICATION

First Line

Treat underlying blepharitis: lid scrubs, artificial tears, antibiotic ointment (erythromycin or bacitracin) 4 times a day

Second Line

• Short course of topical steroid–antibiotic combination 4–6 times a day

• Systemic tetracycline 250 mg q.i.d. for 2–4 weeks (2)[C]

• Topical metronidazole

• Topical antibiotics if bacterial keratitis suspected

Geriatric Considerations

Side effects of long-term topical steroid use include cataract formation and glaucoma.

Pediatric Considerations

Tetracycline contraindicated in children. Substitute erythromycin 250 mg q.i.d.

Pregnancy Considerations

• Tetracycline contraindicated in pregnant or nursing women. Substitute erythromycin 250 mg q.i.d.

• Steroids are class C and of unknown safety in lactation.

ADDITIONAL TREATMENT

General Measures

Treat tuberculosis

Issues for Referral

Recurrent or causing corneal scarring

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

• Mild cases will resolve in 2–4 weeks.

• Follow patient weekly.

PATIENT MONITORING

If cornea involved, monitor for scarring or epithelial defect leading to melting.

PATIENT EDUCATION

Long-term treatment of blepharitis with lid scrubs, artificial tears, and ointment to prevent recurrence

PROGNOSIS

Overall good; if severe, may have residual corneal scarring leading to decreased vision.

COMPLICATIONS

Corneal scarring, decreased vision

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