Conjunctivitis: Bacterial

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Conjunctivitis: Bacterial - Red Eye Bugs

Acute bacterial inflammation of the conjunctiva. Presents with conjunctival injection ("red eye"), mucopurulent discharge (sticky lids, worse on waking), and foreign body sensation. Vision typically unaffected.

  • Causative "Bugs":
    • Adults: Staphylococcus aureus (most common), Streptococcus pneumoniae, Haemophilus influenzae.
    • Children: Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis.
    • Neonates (Ophthalmia Neonatorum):
      • Neisseria gonorrhoeae: Hyperacute, copious pus, sight-threatening. Requires urgent systemic & topical Rx.
      • Chlamydia trachomatis: Subacute, 1-2 weeks post-birth.
  • 📌 Mnemonic: "Sticky eyes in the morning, think bacterial!"

⭐ Most common cause of bacterial conjunctivitis in adults is Staphylococcus aureus, while in children it's often Haemophilus influenzae or Streptococcus pneumoniae.

Bacterial Conjunctivitis with Mucopurulent Discharge

Conjunctivitis: Bacterial - Gooey Eye Clues

  • Hallmark: Purulent/mucopurulent discharge ("gooey eye").
    • Eyelids stuck, esp. on waking.
    • Thick, yellow-green discharge.
  • Onset: Acute.
  • Laterality: Often bilateral; may start unilaterally.
  • Symptoms:
    • Beefy red conjunctival injection.
    • Grittiness, FBS (Foreign Body Sensation).
    • Mild discomfort (⚠️ severe pain = red flag).
    • Vision normal (transient blur from discharge).
  • Signs:
    • Chemosis (conjunctival swelling).
    • Papillary reaction (tarsal conjunctiva).
    • Preauricular nodes usually absent (common in viral).
  • Common Pathogens: S. aureus, Strep. pneumoniae, H. influenzae.
    • Hyperacute (profuse discharge, medical emergency!): N. gonorrhoeae ⚠️.

⭐ Purulent or mucopurulent discharge with eyelids stuck together, especially upon waking, is highly characteristic of bacterial conjunctivitis.

Bacterial Conjunctivitis with Purulent Discharge

Conjunctivitis: Bacterial - ID the Invader

Bacterial Conjunctivitis with Purulent Discharge

  • Hallmarks: Acute onset, redness, irritation, purulent/mucopurulent discharge (yellow-green), lid matting (esp. morning).
  • Transmission: Highly contagious; direct contact with secretions/fomites.
  • Common Pathogens & Features:
    • Staphylococcus aureus: Most frequent in adults; blepharitis common.
    • Streptococcus pneumoniae: Children; often concurrent otitis media; petechial hemorrhages.
    • Haemophilus influenzae: Children; often concurrent otitis media; URI prodrome.
    • Moraxella catarrhalis: Can cause chronic angular blepharoconjunctivitis.
  • Lab Investigations Decision:

Hyperacute conjunctivitis (e.g., N. gonorrhoeae) is an ophthalmic emergency requiring immediate Gram stain, culture, and systemic treatment to prevent corneal perforation.

Conjunctivitis: Bacterial - Banish Redness Fast

Goal: Eradicate infection, relieve symptoms, prevent spread & complications.

  • Topical Antibiotics (First-line): Shorten course, ↓ transmission. Typical duration: 5-7 days.
    • Fluoroquinolones (e.g., moxifloxacin, gatifloxacin).
    • Polymyxin B/trimethoprim.
    • Azithromycin (1% solution, BID for 2 days, then QD for 5 days).
    • Tobramycin, Gentamicin.
    • Chloramphenicol (caution: aplastic anemia).
  • Systemic Antibiotics:
    • Severe infections (e.g., N. gonorrhoeae - Ceftriaxone 1g IM single dose).
    • Chlamydial conjunctivitis (Azithromycin 1g oral single dose).
    • Associated systemic illness (e.g., otitis media).
  • Adjunctive Therapy:
    • Warm compresses.
    • Lid hygiene.
    • Frequent handwashing.
    • Avoid sharing fomites.

⭐ Most cases of acute bacterial conjunctivitis are self-limiting, but topical antibiotics (e.g., fluoroquinolones, polymyxin B/trimethoprim) shorten the clinical course and reduce transmission.

High‑Yield Points - ⚡ Biggest Takeaways

  • Common bacterial causes: Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae.
  • Key signs: Mucopurulent discharge, eyelids stuck together (especially in morning), often bilateral.
  • Hyperacute conjunctivitis: Caused by Neisseria gonorrhoeae, presents with copious purulent discharge, an ophthalmic emergency.
  • Ophthalmia Neonatorum: N. gonorrhoeae (days 2-5), Chlamydia trachomatis (days 5-14).
  • Treatment: Primarily broad-spectrum topical antibiotics (e.g., fluoroquinolones, moxifloxacin).
  • Systemic antibiotics are crucial for gonococcal and chlamydial infections.
  • Highly contagious: Emphasize hand hygiene to prevent transmission and autoinoculation.

Practice Questions: Conjunctivitis: Bacterial

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The severe form of mechanically induced papillary conjunctivitis is known as _____

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The severe form of mechanically induced papillary conjunctivitis is known as _____

giant papillary conjunctivitis.

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