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 such as polymyxin B/trimethoprim, erythromycin, or gentamicin. 1, 2
Treatment Algorithm Based on Severity
Mild Bacterial Conjunctivitis
- Prescribe any broad-spectrum topical antibiotic for 5-7 days, as no clinical evidence demonstrates superiority of one agent over another in uncomplicated cases. 1
- Recommended options include:
- This accelerates clinical and microbiological remission by days 2-5, reduces transmissibility, and allows earlier return to school/work. 1
- Alternative: Povidone-iodine 1.25% ophthalmic solution may be equally effective when antibiotic access is limited. 1, 2
Moderate to Severe Bacterial Conjunctivitis
- Reserve fluoroquinolones (moxifloxacin 0.5%, gatifloxacin 0.5%, ofloxacin 0.3%, or ciprofloxacin) for cases with copious purulent discharge, pain, and marked inflammation. 1, 3
- Obtain conjunctival cultures and Gram staining before initiating treatment to guide therapy. 1, 2, 3
- Fluoroquinolones provide broad-spectrum coverage against Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas. 3
- Gatifloxacin dosing: Instill one drop every 2 hours while awake (up to 8 times) on Day 1, then one drop 2-4 times daily on Days 2-7. 4
Contact Lens Wearers
- Always prescribe fluoroquinolones for contact lens wearers due to higher risk of Pseudomonas infection. 1, 3
- Advise patients not to wear contact lenses during treatment. 4
Special Pathogen Considerations
Gonococcal Conjunctivitis
- Systemic antibiotic therapy is mandatory; topical antibiotics alone are insufficient. 1, 2, 3
- Add saline lavage to promote comfort and faster resolution of inflammation. 1
- Hospitalization may be necessary for severe cases and is mandatory for neonatal infections. 1
- Requires daily follow-up until complete resolution. 3
Chlamydial Conjunctivitis
- Systemic antibiotic therapy is required (oral azithromycin single dose or tetracycline for 7 days in adults); topical therapy alone is inadequate. 1, 2, 3
- For neonates: Erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses for 14 days. 1
- In children with chlamydial or gonococcal conjunctivitis, consider the possibility of sexual abuse. 1, 2
MRSA Conjunctivitis
- MRSA has been isolated with increasing frequency and may require compounded topical vancomycin based on culture results. 1, 3
- Approximately 42% of staphylococcal isolates show methicillin resistance with high concurrent fluoroquinolone resistance. 3
Follow-Up Protocol
- Advise patients to return if no improvement occurs after 3-4 days of treatment. 1, 2, 3
- Follow-up should include visual acuity measurement and slit-lamp biomicroscopy. 1, 2
- If severe inflammation persists, a brief course of topical corticosteroids may be indicated with baseline and periodic intraocular pressure monitoring. 1
Critical Pitfalls to Avoid
- Do not prescribe antibiotics for viral conjunctivitis, which accounts for unnecessary costs and promotes resistance. 1
- Avoid topical corticosteroids unless under close ophthalmologic supervision, as they may prolong bacterial shedding and worsen infection. 2, 3
- Poor adherence to frequent administration regimens contributes to treatment failure. 1
- Bacterial resistance is a growing concern, particularly with MRSA and fluoroquinolone-resistant organisms. 1, 2, 3
When to Refer to Ophthalmology Immediately
- Visual loss or decreased visual acuity 1, 2, 3
- Moderate or severe pain 1, 2
- Severe purulent discharge 1, 2
- Corneal involvement (infiltrate, ulceration, opacity, or scarring) 1, 2, 3
- Lack of response to therapy after 3-4 days 1, 2
- Recurrent episodes 1, 2
- Neonatal conjunctivitis (requires prompt consultation and possible hospitalization) 1, 2