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, with the most convenient or least expensive option being appropriate as no clinical evidence suggests superiority of any particular agent. 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 mandatory hospitalization) 1

Obtain conjunctival cultures and Gram staining before treatment if moderate to severe disease or gonococcal infection is suspected. 3, 1

Treatment Algorithm by Clinical Presentation

Mild Bacterial Conjunctivitis (Typical Outpatient Cases)

Choose the most convenient or least expensive broad-spectrum topical antibiotic for 5-7 days, applied 4 times daily. 1, 2

Effective first-line options include:

• Aminoglycosides (tobramycin, gentamicin) - effective against common pathogens 3, 1
• Fluoroquinolones (moxifloxacin, gatifloxacin, ofloxacin) - superior coverage including S. aureus, S. pneumoniae, and H. influenzae 1
• Polymyxin B/trimethoprim - acceptable alternative 1
• Bacitracin - applied 1-3 times daily directly into conjunctival sac 4

The American Academy of Ophthalmology emphasizes that no clinical evidence suggests superiority of any particular antibiotic for mild cases, so cost and convenience should guide selection. 1

Topical antibiotics accelerate clinical and microbiological remission by days 2-5, reduce transmissibility, and allow earlier return to school/work. 1, 2

Moderate to Severe Bacterial Conjunctivitis

Characterized by copious purulent discharge, pain, and marked inflammation. 2

Reserve fluoroquinolones for moderate to severe cases, particularly in contact lens wearers at higher risk for Pseudomonas infection. 1

• Fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) have superior gram-positive coverage, including some methicillin-resistant S. aureus strains 1
• Obtain cultures and Gram staining before initiating treatment 1, 2

Special Pathogen Considerations

MRSA Conjunctivitis

MRSA isolates are generally resistant to fluoroquinolones and aminoglycosides but susceptible to vancomycin. 1

• May require compounded topical vancomycin 1, 2
• Increasing bacterial resistance is a growing concern 3, 2

Gonococcal Conjunctivitis

Requires systemic antibiotic therapy, not topical treatment alone. 3, 1

• Adults: Ceftriaxone 1 g IM single dose PLUS azithromycin 1 g orally single dose 1
• Add saline lavage to promote comfort and faster resolution 1
• Daily follow-up until resolution required 2
• Topical treatment as for bacterial keratitis if corneal involvement present 2

Chlamydial Conjunctivitis

Requires systemic antibiotic therapy, especially in infants who may have infection at other sites. 3, 1

• No evidence supports additional topical therapy beyond systemic treatment 1
• Neonates: Erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses for 14 days 1
• Follow-up evaluation important as treatment failure occurs in up to 19% of cases 2
• Consider sexual abuse in children with gonococcal or chlamydial infections 1, 2

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

Follow-Up Protocol

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

Follow-up should include:

• Interval history 3, 1
• Visual acuity measurement 3, 1
• Slit-lamp biomicroscopy 3, 1

Critical Pitfalls to Avoid

• Avoid topical corticosteroids unless under close supervision, as they may prolong bacterial shedding and worsen infection 3
• Do not prescribe antibiotics for viral conjunctivitis - this accounts for unnecessary costs and promotes resistance 1
• Poor adherence to frequent administration regimens contributes to treatment failure 1
• Bacterial resistance is increasing, particularly with MRSA 3, 1, 2

Infection Control Measures

Counsel patients on preventing spread through frequent hand washing and avoiding sharing personal items. 3, 1