How do you differentiate and treat conjunctivitis versus scleritis?

Differentiating and Treating Conjunctivitis versus Scleritis

Conjunctivitis is typically a self-limiting condition with minimal complications, while scleritis is a severe ocular inflammation requiring aggressive systemic treatment to prevent vision loss. 1, 2

Clinical Differentiation

Conjunctivitis

• Presentation: Redness, discharge, and mild discomfort
• Pain level: Mild to moderate discomfort
• Discharge:
  • Viral: Watery discharge
  • Bacterial: Mucopurulent discharge
  • Allergic: Watery discharge with itching
• Lymph nodes: Preauricular lymphadenopathy common in viral conjunctivitis 3, 4
• Visual acuity: Usually preserved
• Examination findings:
  • Diffuse conjunctival injection
  • Follicular or papillary reaction
  • Membranes/pseudomembranes in severe cases
  • Cornea typically clear

Scleritis

• Presentation: Severe, deep ocular pain (often radiating to temple/jaw)
• Pain level: Moderate to severe, often waking patient from sleep
• Discharge: Minimal to none
• Visual changes: May have decreased visual acuity (15.9% of cases) 1
• Examination findings:
  • Deep, violaceous injection that doesn't blanch with phenylephrine
  • Scleral edema and thickening
  • Nodules in nodular scleritis
  • Scleral thinning in necrotizing forms
  • May have associated anterior uveitis
  • Ocular complications in 58.8% of cases 1

Diagnostic Approach

Key Diagnostic Features

1. Pain intensity: Mild in conjunctivitis, severe in scleritis
2. Redness pattern:
   • Conjunctivitis: Diffuse, bright red, blanches with phenylephrine
   • Scleritis: Deep, violaceous, doesn't blanch with phenylephrine
3. Slit lamp examination:
   • Conjunctivitis: Surface involvement only
   • Scleritis: Deep scleral involvement, may see nodules or thinning
4. Associated findings:
   • Conjunctivitis: Discharge, follicles/papillae
   • Scleritis: Scleral edema, anterior uveitis

Diagnostic Tests

• For conjunctivitis:

  • Conjunctival swabs for culture in suspected bacterial cases
  • PCR for viral pathogens when needed
  • Allergy testing for suspected allergic conjunctivitis 3, 4

• For scleritis:

  • Laboratory tests for associated systemic diseases:
    • Rheumatoid factor, anti-CCP antibodies
    • ANCA for granulomatosis with polyangiitis
    • ANA for lupus
    • ESR/CRP for inflammation
  • Infectious workup if infectious scleritis suspected 5, 6

Treatment Approaches

Conjunctivitis Treatment

1. Viral conjunctivitis:

   • Supportive care (artificial tears, cold compresses)
   • Strict hygiene to prevent transmission
   • Self-limiting in 1-2 weeks 3, 4, 7

2. Bacterial conjunctivitis:

   • Topical antibiotics (e.g., erythromycin ointment, bacitracin) 8, 9
   • Apply approximately 1 cm of ointment directly to infected eye(s) up to six times daily 9
   • Most cases resolve in 1-2 weeks 7

3. Allergic conjunctivitis:

   • Topical antihistamines and mast cell stabilizers
   • Avoid allergens
   • Cold compresses 3, 4, 7

4. Special cases:

   • Gonococcal/chlamydial conjunctivitis: Requires systemic antibiotics plus topical therapy 3, 7
   • Neonatal conjunctivitis: Prophylaxis with erythromycin ointment 3, 9

Scleritis Treatment

1. Non-necrotizing scleritis (diffuse or nodular):

   • Oral NSAIDs as first-line therapy
   • Oral corticosteroids if NSAIDs insufficient
   • 56.4% of diffuse and 21.4% of nodular cases require systemic corticosteroids or immunosuppressants 1

2. Necrotizing scleritis:

   • Aggressive immunosuppression (90% require systemic corticosteroids or immunosuppressants)
   • Evaluate and treat underlying systemic disease
   • Highest risk of vision loss (50% of cases) 1, 2

3. Posterior scleritis:

   • Systemic immunosuppression (100% require systemic treatment)
   • High risk of complications (85.7%) 1

4. Infectious scleritis:

   • Targeted antimicrobial therapy (systemic and topical)
   • Avoid corticosteroids until infection controlled 6

Complications and Referral

Conjunctivitis Complications

• Generally minimal (13.5% in episcleritis) 1
• Usually no decrease in visual acuity
• Refer to ophthalmologist if:
  • No improvement after 7-10 days
  • Worsening pain or vision changes
  • Corneal involvement
  • Light sensitivity 3, 4

Scleritis Complications

• Much more common (58.8% of cases) 1
• Visual acuity decrease in 15.9% 1
• Scleral thinning, perforation, uveitis
• Associated with systemic disease in approximately 30% of cases 2, 5
• All cases require ophthalmology referral

Key Takeaways

1. Pain severity is a critical differentiator - mild in conjunctivitis, severe in scleritis
2. Conjunctivitis typically resolves without sequelae, while scleritis can threaten vision
3. Most conjunctivitis cases can be managed with topical therapy, while scleritis often requires systemic treatment
4. Scleritis has a strong association with systemic autoimmune diseases and requires interdisciplinary management between ophthalmologists and rheumatologists/internists 2, 5