What is the appropriate management for unilateral conjunctival injection?

Management of Unilateral Conjunctival Injection

The appropriate management of unilateral conjunctival injection requires first identifying the specific etiology, with viral causes typically requiring supportive care while bacterial causes often benefit from topical antibiotics. 1

Diagnostic Approach

Key Clinical Features to Assess

• Discharge characteristics:
  • Watery discharge suggests viral etiology
  • Mucopurulent discharge suggests bacterial infection 2
• Associated symptoms:
  • Preauricular lymphadenopathy (suggests viral, especially adenovirus)
  • Follicular reaction of conjunctiva (suggests viral)
  • Papillary reaction (suggests bacterial or allergic)
  • Pain severity (severe pain may indicate corneal involvement)
• Pattern of redness:
  • Diffuse bulbar conjunctival injection vs. ciliary injection (more concerning)
• Unilateral vs. bilateral presentation:
  • Viral causes often start unilaterally but become sequentially bilateral
  • Bacterial causes can be unilateral or bilateral 2

Common Etiologies of Unilateral Conjunctival Injection

Viral Causes

• Adenovirus: Most common, characterized by watery discharge, follicular reaction, possible preauricular lymphadenopathy 2
• Herpes simplex virus (HSV): Usually unilateral, may have vesicular eyelid lesions or dendritic keratitis 2
• Varicella zoster virus (VZV): Unilateral, associated with dermatomal rash, severe pain 2

Bacterial Causes

• Non-gonococcal: Mucopurulent discharge, no preauricular lymphadenopathy 2
• Gonococcal: Marked purulent discharge, severe lid edema, preauricular lymphadenopathy (requires urgent treatment) 2
• Chlamydial: Follicular conjunctivitis, can be chronic 2

Other Causes

• Allergic: Usually bilateral but can be asymmetric
• Foreign body: Unilateral with localized injection
• Angle closure glaucoma: Can present with unilateral conjunctival injection and severe pain 3
• Neoplastic: Chronic unilateral injection resistant to treatment 2

Management Algorithm

1. Viral Conjunctivitis

• Treatment: Primarily supportive care
  • Cold compresses
  • Artificial tears for comfort
  • Avoid contact lens wear
• Duration: Self-limited, typically resolves within 5-14 days 1
• Special considerations:
  • HSV conjunctivitis may require antiviral therapy if corneal involvement is present
  • Highly contagious; advise strict hand hygiene and avoid sharing personal items

2. Bacterial Conjunctivitis

• Treatment: Topical antibiotics
  • First-line: Fluoroquinolones like moxifloxacin 0.5% ophthalmic solution 3 times daily for 7 days 4
  • Alternative: Aminoglycosides or macrolides
• Duration: Usually resolves within 5-7 days with treatment
• Special considerations:
  • Gonococcal conjunctivitis requires both systemic and topical antibiotics 1
  • Chlamydial conjunctivitis requires systemic treatment (azithromycin or doxycycline) 1

3. Other Causes

• Foreign body: Removal and antibiotic prophylaxis
• Allergic: Topical antihistamines/mast cell stabilizers
• Angle closure glaucoma: Urgent ophthalmology referral 3
• Neoplastic: Ophthalmology referral for biopsy and management 2

Referral Criteria

Immediate ophthalmology referral is indicated for:

• Severe pain
• Decreased vision
• Corneal involvement
• Suspected gonococcal or chlamydial conjunctivitis
• Neonatal conjunctivitis
• Suspected HSV or VZV conjunctivitis
• No improvement after 3 days of appropriate treatment
• Immunocompromised patients 1

Common Pitfalls and Caveats

1. Misdiagnosing HSV conjunctivitis: Can lead to corneal scarring if not properly treated. Look for characteristic dendritic lesions on the cornea.

2. Overlooking angle-closure glaucoma: Can present with unilateral conjunctival injection and requires immediate intervention. Always check intraocular pressure when available 3.

3. Treating viral conjunctivitis with antibiotics: Unnecessary and contributes to antibiotic resistance.

4. Failing to recognize neoplastic causes: Chronic unilateral conjunctival injection resistant to treatment should raise suspicion for ocular surface neoplasia 2.

5. Missing SUNCT syndrome: A rare cause of unilateral conjunctival injection associated with neuralgiform headaches that requires neurological evaluation 5, 6.

6. Inadequate patient education: Patients should be instructed on the contagious nature of infectious conjunctivitis and appropriate hygiene measures.