What is the treatment for bacterial conjunctivitis (pink eye)?

Treatment for Bacterial Conjunctivitis (Pink Eye)

Topical broad-spectrum antibiotics are the first-line treatment for bacterial conjunctivitis, with a standard course of 5-7 days until resolution of discharge, no more matting of eyelids, and reduction in conjunctival injection. 1

Diagnosis and Clinical Presentation

Bacterial conjunctivitis typically presents with:

• Purulent or mucopurulent discharge
• Matting of eyelids (especially in the morning)
• Conjunctival injection (redness)
• Mild discomfort or foreign body sensation
• Absence of significant pain or vision loss

Common causative organisms include:

• Haemophilus influenzae
• Streptococcus pneumoniae
• Staphylococcus aureus
• Moraxella species

Treatment Algorithm

First-Line Treatment

1. Topical broad-spectrum antibiotics 1

   • Options include:
     • Polymyxin B-trimethoprim ophthalmic solution (effective against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa) 2, 3
     • Fluoroquinolones (e.g., moxifloxacin 0.5% ophthalmic solution) 1
     • Aminoglycosides (e.g., gentamicin) 1
     • Sulfacetamide sodium ophthalmic solution 4

2. Dosing regimen:

   • Apply 1-2 drops into affected eye(s) every 2-3 hours initially 4
   • Taper frequency as condition improves
   • Continue for 5-7 days or until resolution of symptoms 1

Supportive Measures

• Warm compresses to soften discharge and loosen crusts 1
• Frequent handwashing to prevent spread
• Avoid sharing towels and pillowcases 1

Special Considerations

Contact Lens Wearers

• Discontinue lens wear until infection resolves 1
• Consider switching to new lenses after resolution

Severe Purulent Discharge

• May indicate more virulent organisms requiring aggressive treatment 1
• Consider cultures in these cases

Gonococcal/Chlamydial Conjunctivitis

• Requires systemic antibiotics in addition to topical therapy 1
• Gonococcal: systemic ceftriaxone
• Chlamydial: systemic azithromycin, doxycycline, or levofloxacin

Evidence on Effectiveness

Topical antibiotics have been shown to:

• Shorten the duration of clinical disease 5
• Enhance eradication of causative organisms 5
• Improve early (days 2-5) clinical remission rates by 36% compared to placebo 6
• Improve late (days 6-10) clinical remission rates by 21% compared to placebo 6

When to Refer to an Ophthalmologist

Refer if:

• No response to therapy after 3-4 days
• Moderate to severe pain
• Decreased vision
• Corneal involvement
• Recurrent episodes
• History of herpes simplex virus eye disease
• Immunocompromised patient 1

Important Caveats

• Bacterial conjunctivitis is often self-limiting (41% of cases resolve without antibiotics by days 6-10) 6
• Increasing resistance to fluoroquinolones has been reported, particularly in MRSA isolates 1
• Indiscriminate use of antibiotics should be avoided 1
• Ocular ointments may be useful at bedtime but have limited corneal penetration for severe infections 7

Remember that while bacterial conjunctivitis is typically self-limiting, antibiotic treatment speeds resolution of symptoms and infection, reducing the risk of complications and spread to others.