Treatment of Bacterial Conjunctivitis
First-Line Treatment Recommendation
For uncomplicated bacterial conjunctivitis, prescribe a topical fluoroquinolone (moxifloxacin 0.5% or ofloxacin 0.3%) four times daily for 5-7 days. 1
Treatment Algorithm by Clinical Presentation
Mild to Moderate Bacterial Conjunctivitis (Immunocompetent Patients)
- Topical fluoroquinolones are the preferred first-line agents, with moxifloxacin 0.5% offering superior gram-positive coverage including some MRSA strains. 1
- No single antibiotic has demonstrated superiority for uncomplicated cases, so selection can be based on dosing convenience, cost, and local resistance patterns. 1, 2
- Standard dosing is four times daily for 5-7 days, which provides earlier clinical and microbiological remission (68% cure rate versus 55% with placebo by days 4-9) and allows faster return to work or school. 1, 2
- Alternative agents include topical gentamicin, tetracycline, or ofloxacin 0.3% if fluoroquinolones are unavailable. 1
Severe Bacterial Conjunctivitis (Copious Purulent Discharge, Pain, Marked Inflammation)
- Obtain conjunctival cultures and Gram staining before initiating treatment, especially if gonococcal infection is suspected. 1, 2
- Consider MRSA in patients from nursing homes or with community-acquired infections; these cases may require compounded topical vancomycin if unresponsive to fluoroquinolones within 48-72 hours. 1
- Immediate ophthalmology referral is mandatory for corneal involvement, visual loss, moderate to severe pain, or lack of response after 3-4 days. 1
Special Pathogens Requiring Systemic Antibiotics
Gonococcal Conjunctivitis
- Systemic antibiotics are mandatory; topical therapy alone is insufficient. 1, 2
- Adult treatment: Ceftriaxone 250 mg IM single dose plus azithromycin 1 g oral single dose. 1
- Neonatal treatment: Ceftriaxone 25-50 mg/kg IV or IM single dose (maximum 125 mg). 1, 3
- Daily monitoring until resolution is required to prevent corneal perforation. 1
- Consider sexual abuse in children presenting with gonococcal conjunctivitis. 1, 3
Chlamydial Conjunctivitis
- Systemic therapy is required because more than 50% of infants have concurrent infection at other sites (nasopharynx, genital tract, lungs). 1, 2
- Adult treatment: Azithromycin 1 g oral single dose or doxycycline 100 mg oral twice daily for 7 days. 1
- Neonatal treatment: Erythromycin base or ethylsuccinate 50 mg/kg/day oral divided into 4 doses for 14 days. 1, 3
- Topical antibiotics provide no additional benefit beyond systemic treatment. 1, 2
- Consider sexual abuse in children presenting with chlamydial conjunctivitis. 1, 3
Pediatric Considerations
- Fluoroquinolones are FDA-approved for children older than 12 months, including besifloxacin, levofloxacin, gatifloxacin, ciprofloxacin, moxifloxacin, and ofloxacin. 1, 3
- Neonatal conjunctivitis (birth to 28 days) always requires immediate evaluation due to risk of corneal perforation, septicemia, and meningitis. 3
- Children can return to school 24 hours after initiating treatment once symptoms begin to improve. 3
When Topical Antibiotics Are NOT Indicated
- Viral conjunctivitis should be managed with supportive care alone (refrigerated preservative-free artificial tears four times daily and cold compresses); topical antibiotics provide no benefit and promote resistance. 1
- Allergic conjunctivitis requires topical antihistamines with mast cell-stabilizing properties, not antibiotics. 1
Follow-Up and Monitoring
- Instruct patients to return in 3-4 days if no improvement is noted. 1, 3, 2
- At follow-up, perform interval history, visual acuity measurement, and slit-lamp biomicroscopy to assess response and rule out complications. 1
- Signs of positive response include reduced pain and discharge, decreased eyelid edema or conjunctival injection, and initial re-epithelialization. 1
Critical Red Flags Requiring Immediate Ophthalmology Referral
- Visual loss or significant change in vision 1
- Moderate to severe eye pain (beyond mild irritation) 1
- Severe purulent discharge suggestive of gonococcal infection 1
- Corneal involvement (opacity, infiltrate, or ulcer) 1
- Conjunctival scarring 1
- Lack of response to therapy after 3-4 days 1
- Recurrent episodes 1
- History of HSV eye disease 1
- Immunocompromised state 1
Common Pitfalls and How to Avoid Them
- Never use topical corticosteroids without definitively ruling out HSV conjunctivitis, as steroids potentiate viral replication and worsen infection. 1
- Do not prescribe oral antibiotics for routine bacterial conjunctivitis; they are reserved exclusively for gonococcal and chlamydial infections. 1
- Avoid combination antibiotic-steroid drops (e.g., Tobradex) unless viral etiology has been definitively excluded, as steroids can prolong adenoviral infections and exacerbate HSV. 1
- Counsel patients on strict hand hygiene, avoiding eye rubbing, using separate towels, and avoiding close contact during the contagious period to prevent transmission. 1
- Be aware of geographic resistance patterns: In some regions, Pseudomonas aeruginosa resistance to moxifloxacin has increased from 19% to 52%, and 42% of MRSA isolates show concurrent fluoroquinolone resistance. 1
Alternative When Antibiotics Are Unavailable
- Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotics and is a viable option in settings with limited antibiotic access. 1, 2
- Mild bacterial conjunctivitis is self-limited and resolves spontaneously in approximately 64% of cases by days 6-10 without treatment. 1