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. 1, 2

Initial Assessment and Diagnosis

• Bacterial conjunctivitis typically presents with marked inflammation, purulent discharge, and sometimes pain, often with morning crusting and difficulty opening eyelids 3, 4
• Examine for swollen preauricular or submandibular lymph nodes, which may indicate bacterial infection 3
• For uncomplicated mild cases, cultures are NOT routinely needed and diagnosis can be made clinically 1
• Obtain conjunctival cultures and Gram staining before treatment in moderate to severe cases (copious purulent discharge, pain, marked inflammation), especially if gonococcal infection is suspected 3, 1, 2

Treatment Algorithm by Severity

Mild Bacterial Conjunctivitis

• Apply broad-spectrum 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, 1
• Choose the most convenient or least expensive option as no clinical evidence suggests superiority of any particular antibiotic 1, 2

Recommended first-line options:

• Aminoglycosides (tobramycin, gentamicin) - effective against common bacterial pathogens 3, 1
• Polymyxin B/trimethoprim - broad-spectrum coverage 1, 5
• Bacitracin ointment - apply 1-3 times daily directly into conjunctival sac 6
• Erythromycin - remains a viable option per WHO endorsement 1

Moderate to Severe Bacterial Conjunctivitis

• Reserve fluoroquinolones (moxifloxacin, gatifloxacin, ofloxacin, ciprofloxacin) for moderate to severe cases with copious purulent discharge, pain, and marked inflammation 1
• Fluoroquinolones are particularly important for contact lens wearers at higher risk for Pseudomonas infection 1
• Fourth-generation fluoroquinolones (moxifloxacin, gatifloxacin) have better gram-positive coverage, including some MRSA strains 1
• Guide antibiotic choice by culture and Gram stain results 2

Special Cases Requiring Systemic Therapy

Gonococcal Conjunctivitis

• Requires systemic antibiotic therapy, NOT topical treatment alone 3, 1, 2
• Add saline lavage to promote comfort and faster resolution 1
• Daily follow-up until resolution is mandatory 2
• Hospitalization may be necessary for severe cases and is mandatory for neonatal conjunctivitis 1

Chlamydial Conjunctivitis

• Requires systemic antibiotic therapy, especially in infants who may have infection at other sites 3, 1, 2
• For neonates: erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses for 14 days (96% clinical cure rate, 97% microbiological cure rate) 1
• No evidence supports additional topical therapy beyond systemic treatment 1
• Follow-up evaluation is important as treatment failure occurs in up to 19% of cases 2

MRSA Conjunctivitis

• May require compounded topical vancomycin, as MRSA is resistant to many commercially available topical antibiotics including aminoglycosides and fluoroquinolones 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

Critical Pitfalls to Avoid

• Never use topical corticosteroids unless under close supervision, as they may prolong bacterial shedding and worsen infection 3
• Avoid prescribing antibiotics for viral conjunctivitis, which promotes unnecessary costs and resistance 1
• Do not use fluoroquinolones as first-line therapy for mild cases - save them for severe infections due to broad spectrum activity and resistance concerns 7
• Increasing bacterial resistance is a concern, particularly with MRSA 3, 1, 2
• Poor adherence to frequent administration regimens contributes to treatment failure 1, 8

Follow-up Protocol

• Advise patients to return if no improvement after 3-4 days of treatment 3, 1, 2
• At follow-up, perform interval history, visual acuity measurement, and slit-lamp biomicroscopy 3, 1

When to Refer to Ophthalmology

Immediate referral indicated for: 3, 1

• Visual loss
• Moderate or severe pain
• Severe purulent discharge
• Corneal involvement
• Conjunctival scarring
• Lack of response to therapy
• Recurrent episodes
• Neonates with HSV infection (life-threatening)

Infection Control Measures

• Counsel patients on frequent hand washing to prevent spread 1
• Avoid sharing personal items 3
• For children with gonococcal or chlamydial infections, consider the possibility of sexual abuse 1, 2