Treatment Options for Unilateral Conjunctivitis
The appropriate treatment for unilateral conjunctivitis depends primarily on identifying the specific etiology, with viral causes typically requiring supportive care while bacterial causes often benefit from topical antibiotics. 1
Diagnostic Approach to Unilateral Conjunctivitis
Unilateral conjunctivitis can be caused by several different etiologies, each requiring specific treatment:
Viral Conjunctivitis
- Usually unilateral initially (may become bilateral)
- Watery discharge
- Follicular reaction of inferior tarsal conjunctiva
- Preauricular lymphadenopathy
- Common causes: adenovirus, herpes simplex virus (HSV)
Bacterial Conjunctivitis
- Can be unilateral or bilateral
- Mucopurulent or purulent discharge
- Eyelids may be matted shut, especially upon waking
- Papillary reaction more common than follicular
Herpes Simplex Virus (HSV)
- Almost always unilateral
- Watery discharge
- Mild follicular reaction
- May have palpable preauricular node
- May have associated vesicular skin lesions
Herpes Zoster Virus (VZV)
- Strictly unilateral
- Vesicular dermatomal rash
- Pseudodendritic epithelial keratitis
Molluscum Contagiosum
- Typically unilateral
- Associated with characteristic umbilicated eyelid lesions
- Follicular reaction
Treatment Options by Etiology
1. Viral Conjunctivitis Treatment
- Supportive care is the mainstay of treatment 2
- Artificial tears for comfort
- Cold compresses to reduce inflammation
- Strict hand hygiene to prevent transmission
- For HSV conjunctivitis: Antiviral therapy is required
- Trifluridine ophthalmic solution for HSV keratitis 3
- Oral antivirals may be needed for more severe cases
- For VZV conjunctivitis: Antiviral therapy (oral or topical)
- Duration: Usually self-limited, resolving within 5-14 days 1
2. Bacterial Conjunctivitis Treatment
- Topical antibiotics are the standard treatment 4
- Fluoroquinolones (moxifloxacin, gatifloxacin) are effective broad-spectrum options
- Moxifloxacin 0.5% ophthalmic solution 3 times daily for 4 days has shown 66-69% clinical cure rates 5
- Gatifloxacin is effective against common bacterial pathogens including S. aureus, S. epidermidis, and H. influenzae 6
- Duration: Most cases resolve within 1-3 days with appropriate antibiotic treatment 3
- Special considerations:
3. Molluscum Contagiosum-Associated Conjunctivitis
- Treatment involves removal of the eyelid lesions 1
- May require referral to ophthalmology
4. Allergic Conjunctivitis (if unilateral)
- Topical antihistamines with mast cell-stabilizing activity 2
- Cold compresses
- Allergen avoidance
When to Refer to Ophthalmology
Immediate referral is indicated for:
- Severe pain
- Decreased vision
- Corneal involvement
- Gonococcal or chlamydial conjunctivitis
- Neonatal conjunctivitis
- Herpes simplex or zoster conjunctivitis
- No improvement after 3 days of appropriate treatment
- Immunocompromised patients
Important Considerations and Pitfalls
Never use corticosteroid-containing eye drops unless the conjunctivitis is proven to be non-herpetic, as steroids can worsen herpetic infections 3
Contact lens wearers with unilateral conjunctivitis should:
- Stop wearing contacts immediately
- Be treated for bacterial conjunctivitis
- Be evaluated for corneal ulcers 8
Delayed vs. immediate antibiotics: For mild bacterial conjunctivitis, delayed antibiotic prescribing has shown similar outcomes to immediate prescribing 2
Bacterial resistance: Newer fluoroquinolones like besifloxacin have been developed to address concerns about bacterial resistance 9
Persistence of symptoms beyond the expected timeframe warrants reassessment and possible referral to an ophthalmologist 3
By following this treatment algorithm based on the specific etiology of unilateral conjunctivitis, clinicians can provide effective care while minimizing complications and unnecessary antibiotic use.