What is the recommended treatment for a patient with bacterial conjunctivitis?

Treatment of Bacterial Conjunctivitis

For mild bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical antibiotic applied 4 times daily, choosing the most convenient or least expensive option since no evidence shows superiority of any particular agent in uncomplicated cases. 1, 2

Initial Assessment and Red Flags

Before initiating treatment, evaluate for features requiring immediate ophthalmology referral:

• Visual loss, moderate to severe pain, or severe purulent discharge 1
• Corneal involvement or conjunctival scarring 1
• Immunocompromised state or history of HSV eye disease 1
• Neonatal conjunctivitis (requires hospitalization) 1

For moderate to severe cases with copious purulent discharge, pain, and marked inflammation, obtain conjunctival cultures and Gram staining before starting antibiotics, especially if gonococcal infection is suspected. 1, 2

First-Line Antibiotic Selection

For Mild Cases (Typical Outpatient Presentation)

Select based on convenience and cost, as clinical evidence does not demonstrate superiority of any particular agent: 1, 2

• Aminoglycosides (tobramycin, gentamicin): Effective against common bacterial pathogens 3
• Polymyxin B/trimethoprim: Appropriate for uncomplicated cases 1
• Bacitracin: Apply 1-3 times daily directly into the conjunctival sac 4
• Fluoroquinolones (moxifloxacin, gatifloxacin, ofloxacin): Reserve for specific indications below 1

The World Health Organization endorses topical gentamicin, tetracycline, and ofloxacin for bacterial conjunctivitis. 1

When to Use Fluoroquinolones

Reserve fluoroquinolones for moderate to severe cases or specific risk factors: 1

• Contact lens wearers (higher risk for Pseudomonas infection) 1
• Copious purulent discharge with marked inflammation 1
• Suspected resistant organisms 1

Fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) provide superior gram-positive coverage, including some methicillin-resistant S. aureus strains, compared to earlier generations. 1

Special Clinical Scenarios Requiring Different Management

Gonococcal Conjunctivitis

Topical antibiotics alone are insufficient—systemic therapy is mandatory: 3, 1, 2

• Adults: Ceftriaxone 1 g IM single dose PLUS azithromycin 1 g orally single dose 1
• Add saline lavage for comfort and faster resolution 1
• Requires daily follow-up until resolution 2
• If corneal involvement present, treat as bacterial keratitis 2

Chlamydial Conjunctivitis

Requires systemic antibiotics, not topical therapy: 3, 1, 2

• Neonates: Erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses for 14 days (clinical cure rate 96%, microbiological cure 97%) 1
• Especially critical in infants who may have infection at other sites 1
• Follow-up evaluation essential as treatment failure occurs in up to 19% of cases 2
• Consider sexual abuse in children with gonococcal or chlamydial infections 1, 2

MRSA Conjunctivitis

Standard antibiotics are ineffective—compounded vancomycin required: 1

• MRSA isolates are resistant to fluoroquinolones and aminoglycosides but susceptible to vancomycin 1
• Compounded topical vancomycin may be necessary 1, 2
• Patients with recurrent infections may benefit from decolonization strategies, as S. aureus colonization of nasopharynx, oropharynx, and ocular surface may be the source 1

Alternative Treatment Option

Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotics and can be considered when access to antibiotics is limited. 3, 1, 2

Dosing and Duration

• Standard regimen: Apply topical antibiotic 4 times daily for 5-7 days 3, 1, 2
• This accelerates clinical and microbiological remission in days 2-5, reduces transmissibility, and allows earlier return to school/work 3, 2

Follow-Up Protocol

Instruct patients to return if no improvement after 3-4 days of treatment. 3, 1, 2

At follow-up, perform:

• Interval history 1
• Visual acuity measurement 1
• Slit-lamp biomicroscopy 1

Critical Pitfalls to Avoid

• Never use topical corticosteroids unless under close ophthalmologic supervision, as they may prolong bacterial shedding and worsen infection 3
• Avoid prescribing antibiotics for viral conjunctivitis, which causes unnecessary costs and promotes resistance 1
• Do not use fluoroquinolones indiscriminately for mild cases—save them for severe infections to prevent resistance 5
• Recognize increasing bacterial resistance, particularly with MRSA, which is a growing concern 3, 1, 2

Infection Control Measures

Counsel patients on preventing spread: 1

• Frequent hand washing 1
• Avoid sharing personal items 3
• These measures are essential for preventing transmission 1