What is the recommended treatment for a patient with conjunctivitis and corneal abrasion, considering their medical history and potential allergies?

Treatment of Conjunctivitis with Corneal Abrasion

For a patient with both conjunctivitis and corneal abrasion, initiate topical fluoroquinolone monotherapy (moxifloxacin 0.5% or gatifloxacin 0.5%) four times daily until complete epithelial healing is confirmed, avoiding any corticosteroid-containing drops initially. 1

Initial Management Algorithm

Step 1: Determine the Etiology of Conjunctivitis

The presence of corneal abrasion changes your treatment approach fundamentally—you must prioritize infection prevention over treating the conjunctivitis etiology 1:

• If bacterial conjunctivitis is suspected (mucopurulent discharge, matted eyelids): The fluoroquinolone covers both the abrasion and the conjunctivitis 1, 2
• If viral conjunctivitis is suspected (watery discharge, preauricular lymphadenopathy): Still use fluoroquinolone for the abrasion; add supportive care (refrigerated preservative-free artificial tears four times daily, cold compresses) for viral symptoms 2, 1
• If allergic conjunctivitis is suspected (itching predominates): Use fluoroquinolone for the abrasion; add topical antihistamine/mast cell stabilizer for allergic symptoms after 24-48 hours if needed 2, 1

Step 2: Select the Appropriate Antibiotic

Preferred regimen: Moxifloxacin 0.5% or gatifloxacin 0.5% one drop four times daily 1

• Fourth-generation fluoroquinolones achieve high corneal tissue levels and provide broad-spectrum coverage against both gram-positive and gram-negative organisms 1, 2
• Moxifloxacin has superior gram-positive coverage, including activity against some MRSA strains 2
• Initiate within 24 hours of injury to maximize effectiveness in preventing bacterial ulceration 1

Alternative if fluoroquinolones unavailable: Polymyxin-bacitracin ointment applied to conjunctival sac 1-3 times daily 3, 4

Step 3: Critical Special Populations

Contact lens wearers require escalated management 1:

• Fluoroquinolones with antipseudomonal coverage are mandatory due to dramatically increased risk of Pseudomonas keratitis 1
• Never patch the eye as this increases bacterial keratitis risk 1
• Advise complete avoidance of contact lens wear until healing is confirmed 1

What to Absolutely Avoid

Never use combination steroid-antibiotic drops (like Tobradex) as initial therapy 1:

• Topical corticosteroids delay epithelial healing and increase infection risk in corneal abrasions 1
• Steroids should only be added after 2-3 days of antibiotic-only therapy if bacterial infection is controlled 1
• You must definitively rule out viral conjunctivitis (especially HSV) before considering any steroid, as corticosteroids potentiate HSV infection and prolong adenoviral infections 2, 1

Never patch the eye 1:

• Eye patching does not improve pain and may delay healing 1
• Particularly dangerous in contact lens wearers 1

Adjunctive Pain Management

• Prescribe oral acetaminophen or NSAIDs for pain control 1
• Consider topical cycloplegics if significant photophobia or ciliary spasm is present 5

Follow-Up Protocol

All patients require re-evaluation within 24 hours to assess healing and detect early infection 1:

• Monitor for warning signs requiring immediate ophthalmology referral: increasing pain, purulent discharge, corneal infiltrate, or vision loss 1, 2
• Continue antibiotics until complete epithelial healing is confirmed by examination 1
• Limit antibiotic duration to the healing period only, as chronic prophylactic use promotes resistant organisms 1

When to Refer to Ophthalmology Immediately

Refer urgently if any of the following are present 2, 1:

• Visual loss or moderate to severe pain 2
• Severe purulent discharge suggesting gonococcal infection 2
• Corneal infiltrate, ulcer, or opacity developing 2
• History of HSV eye disease 2
• Immunocompromised state 2
• No improvement or worsening after 24-48 hours of treatment 1

Common Pitfalls to Avoid

• Using antibiotics for viral conjunctivitis alone promotes resistant organisms without benefit, but the presence of corneal abrasion changes this calculation—prophylactic antibiotics are indicated for the abrasion regardless of conjunctivitis etiology 1, 2
• Confusing the need for steroids: While steroids may eventually be appropriate for severe adenoviral conjunctivitis complications or post-viral subepithelial infiltrates, they are contraindicated initially when a corneal abrasion is present 2, 6, 1
• Failing to consider gonococcal or chlamydial conjunctivitis: These require systemic antibiotics (ceftriaxone 250 mg IM plus azithromycin 1 g orally) in addition to topical therapy, with daily monitoring until resolution 2