Recommended Ointment for Bacterial Conjunctivitis
For uncomplicated bacterial conjunctivitis in adults and children over 12 months, erythromycin ophthalmic ointment 0.5% applied directly to the conjunctival sac up to 6 times daily (depending on severity) is the standard first-line treatment, though polymyxin B-bacitracin or polymyxin B-trimethoprim ointments are equally effective alternatives. 1, 2, 3
Treatment Algorithm by Age and Clinical Presentation
Neonates (Birth to 1 Month)
- Erythromycin 0.5% ophthalmic ointment is the standard prophylactic and treatment agent for ophthalmia neonatorum, applied as a 1 cm ribbon into each lower conjunctival sac 1, 3
- For chlamydial conjunctivitis: Systemic erythromycin 50 mg/kg/day orally divided into 4 doses for 14 days is mandatory (topical therapy alone is insufficient due to risk of concurrent nasopharyngeal, genital, or pulmonary infection) 4
- For gonococcal conjunctivitis: Immediate hospitalization with ceftriaxone 25-50 mg/kg IV/IM single dose plus saline lavage; this is a vision-threatening emergency requiring immediate ophthalmology consultation 4
Children (1 Month to 18 Years)
- First-line: Topical fluoroquinolone ointment or drops 4 times daily for 5-7 days 2
- Alternative: Polymyxin B-trimethoprim or polymyxin B-bacitracin ointment 4 times daily for 5-7 days 2, 5, 6
- Erythromycin ointment remains an acceptable option, applied up to 6 times daily depending on severity 3
Adults
- No single antibiotic has demonstrated superiority over others for uncomplicated bacterial conjunctivitis 1
- Acceptable options include erythromycin, polymyxin B-bacitracin, polymyxin B-trimethoprim, or fluoroquinolone ointments 1, 3
- WHO guidelines endorse topical gentamicin, tetracycline, or ofloxacin for bacterial conjunctivitis 1
Key Clinical Considerations
When Antibiotics Provide Benefit
- Topical antibiotics accelerate clinical remission: 62% cured by days 3-5 with treatment versus 28% with placebo 5
- By days 6-10,91% treated patients cured versus 72% placebo (though 41% of untreated cases resolve spontaneously by this time) 7
- Bacterial eradication occurs in 71% by days 3-5 and 79% by days 8-10 with antibiotics, versus only 19% and 31% with placebo 5
Important Caveats and Pitfalls
- Avoid indiscriminate use: Mild bacterial conjunctivitis is often self-limited, and viral conjunctivitis will not respond to antibacterial agents 1
- Never use combination antibiotic-steroid preparations unless viral (especially herpetic) etiology is definitively excluded 8
- Sulfacetamide has significant limitations: A substantial percentage of staphylococcal isolates are completely resistant, and it provides inadequate coverage against Neisseria, Serratia, and Pseudomonas 9
- Contact lens wearers require ophthalmology referral due to higher risk of Pseudomonas keratitis and other serious complications 2
Red Flags Requiring Immediate Ophthalmology Referral
- Visual loss, severe pain, or corneal involvement 2, 4
- Severe purulent discharge (obtain cultures before treatment) 2
- Lack of improvement after 3-4 days of appropriate antibiotic therapy 2, 4
- Suspected gonococcal conjunctivitis (hyperacute presentation with copious purulent discharge) 1
Infection Control Measures
- Patients should wash hands frequently with soap and water (not sanitizer alone), use separate towels/pillows, and avoid close contact for 10-14 days from symptom onset 1
- Children may return to school 24 hours after initiating treatment once symptoms begin improving 2
- Healthcare workers and childcare providers should avoid work during the contagious period 1
Resistance Patterns
- Streptococcus pneumoniae shows the greatest antibiotic resistance among common conjunctival pathogens 10
- Ciprofloxacin, chloramphenicol, and rifampin demonstrate activity against the most prevalent pathogens (H. influenzae and S. pneumoniae) 10
- Methicillin-resistant S. aureus (MRSA) is an increasing concern 2