Acute Bacterial Conjunctivitis

Introduction

Acute conjunctivitis can be:

• Bacterial
• Viral
• Allergic
• Irritative/Chemical

While often diagnosed clinically, distinguishing mild bacterial conjunctivitis from viral or allergic types can be difficult. Empiric treatment is typically initiated.

Always consider serious causes in at-risk groups, including:

• Hypopyon
• Gonococcal conjunctivitis
• Trachoma
• Herpetic infection

Epidemiology

• Common worldwide, especially in children under 5 years
• Gonococcal outbreaks reported in northern and central Australia
• Trachoma remains a major issue in Aboriginal communities
• Human-to-human transmission via contact with infected conjunctival or respiratory secretions
• Neonatal transmission can occur during vaginal delivery

Pathology

Common Bacterial Pathogens

Common	Less Common / High-Risk
Haemophilus influenzae	Pseudomonas aeruginosa
Streptococcus pneumoniae	Staphylococcus aureus
	Neisseria gonorrhoeae
	Neisseria meningitidis
	Chlamydia trachomatis (trachoma)

• Incubation:
  • Bacterial: 24–72 hours
  • Trachoma: 5–12 days
• Reservoir: Humans
• Transmission: Direct contact, respiratory droplets, flies (trachoma)
• Infectious Period: While discharge is present
• Susceptibility: Universal; maternal immunity not protective

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Clinical Assessment

Serious Causes to Consider

1. High-Risk Groups
   • Aboriginal populations (trachoma)
     • Look for follicles, diffuse inflammation, or trichiasis
   • Neonates
     • Increased risk of gonococcal, meningococcal, and staphylococcal infections
2. Hypopyon
   • Must be actively excluded
3. Foreign Body
   • Exclude predisposing irritants
4. Herpetic Infection
   • Requires slit lamp exam
   • Look for dendritic ulcer or nasociliary involvement (zoster)

Typical Presentation of Bacterial Conjunctivitis

• Ocular discomfort or “grittiness”
• Photophobia
• Conjunctival inflammation
• Purulent discharge
• Starts unilateral → becomes bilateral via cross-contamination
• 64% resolve spontaneously in 5 days (may last up to 14 if untreated)

Investigations

When to Investigate	What to Order
Severe or high-risk cases (gonococcus, trachoma, neonates)	Swab for culture & PCR
Herpetic infection suspected	Slit lamp exam

Management

1. Irrigation
   • Sterile saline to remove discharge
2. Avoid Eye Padding
3. Analgesia
   • Oral analgesics as needed
4. Anti-Irritant Drops
   • Phenylephrine 0.12% for symptomatic relief
5. Antibiotics
   • Quinolones, gentamicin, and tobramycin are available but not first-line for uncomplicated cases.
   • Neisseria spp. → require systemic antibiotics and specialist input
   • Trachoma → systemic azithromycin or erythromycin (per guidelines)

Drug	Dosing
Chloramphenicol	Drops 0.5%: 1–2 drops 2-hourly, then reduce to 6-hourly as improved
	Ointment 1%: Use at bedtime
Framycetin	Drops 0.5%: 1–2 drops 1–2 hourly, then reduce to 8-hourly as improved

6. Avoid:
   • Topical steroids
   • Topical anaesthetics
7. Referral Criteria
   • No improvement with treatment
   • Visual impairment
   • Suspected herpes, gonococcus, chlamydia
   • All neonates → refer to paediatrics

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Appendix 1

Appendix 2

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References

FOAMed

• Nickson C. Ophthalmology Befuddler. Clinical Cases. LITFL
• Nickson C. A Gritty Sticky Red Eye. LITFL

Publications

• Roper-Hall MJ. Thermal and chemical burns. Trans Ophthalmol Soc U K (1962). 1965;85:631-53.
• Dua HS, King AJ, Joseph A. A new classification of ocular surface burns. Br J Ophthalmol. 2001 Nov;85(11):1379-83.
• The Eye Emergency Manual, NSW Department of Health, 2nd ed. 2009