What is the treatment for bacterial conjunctivitis?

Treatment for 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 Treatment Approach

Mild Cases (Most Common)

• Prescribe any broad-spectrum topical antibiotic for 5-7 days, 4 times daily 1, 2
• Acceptable first-line options include:
  • Polymyxin B/trimethoprim 1
  • Tobramycin 1, 3
  • Erythromycin 1
  • Gentamicin 1
• The American Academy of Ophthalmology explicitly states no clinical evidence suggests superiority of any particular antibiotic for mild cases, so choose based on cost and convenience 1, 2
• Treatment accelerates clinical and microbiological remission by days 2-5, reduces transmissibility, and allows earlier return to school/work 1, 2

Moderate to Severe Cases

• Reserve fluoroquinolones (moxifloxacin, gatifloxacin, ofloxacin, ciprofloxacin) for copious purulent discharge, pain, and marked inflammation 1, 3
• Obtain conjunctival cultures and Gram staining before initiating treatment 1, 3
• Moxifloxacin 0.5%: instill 1 drop 3 times daily for 7 days 4
• Azithromycin 1%: instill 1 drop twice daily (8-12 hours apart) for 2 days, then once daily for 5 days 5

Contact Lens Wearers

• Must use fluoroquinolones due to higher risk of Pseudomonas infection 1, 3
• Advise against wearing contact lenses during treatment 4, 5

Special Situations Requiring Systemic Therapy

Gonococcal Conjunctivitis

• Requires systemic antibiotics—topical therapy alone is insufficient 1, 3, 2
• Add saline lavage for comfort and faster resolution 1
• Daily follow-up until resolution 2
• Consider sexual abuse in children 1, 2

Chlamydial Conjunctivitis

• Requires systemic antibiotics, especially in infants who may have infection at other sites 1, 3, 2
• For neonates: erythromycin base or ethylsuccinate 50 mg/kg/day divided into 4 doses for 14 days 1
• No evidence supports adding topical therapy beyond systemic treatment 1
• Treatment failure occurs in up to 19% of cases, requiring follow-up 2
• Consider sexual abuse in children 1, 2

MRSA Conjunctivitis

• May require compounded topical vancomycin since MRSA is resistant to most commercially available topical antibiotics including aminoglycosides 1, 2

Alternative When Antibiotics Are Limited

• Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotics 1, 3, 2
• Consider when access to antibiotics is limited 1, 3, 2

Follow-Up Protocol

When to Schedule Return Visit

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

When to Refer to Ophthalmology

Refer immediately for: 1, 3

• Visual loss
• Moderate or severe pain
• Severe purulent discharge
• Corneal involvement
• Conjunctival scarring
• Lack of response to therapy
• Recurrent episodes
• Neonatal conjunctivitis requires hospitalization 1

Critical Pitfalls to Avoid

Resistance Concerns

• Bacterial resistance is increasing, particularly with MRSA 1, 3, 2
• Poor adherence to frequent dosing regimens contributes to treatment failure 1
• Avoid prolonged use to prevent overgrowth of resistant organisms 4, 5

Corticosteroid Use

• Avoid topical corticosteroids unless under close ophthalmology supervision, as they may prolong bacterial shedding and worsen infection 3
• If severe inflammation requires brief corticosteroid course, measure intraocular pressure at baseline and periodically 1

Misdiagnosis

• Do not prescribe antibiotics for viral conjunctivitis—this accounts for unnecessary costs and promotes resistance 1
• Viral conjunctivitis is self-limiting and requires only supportive care 3