Conjunctivitis: Bacterial

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.

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.

Conjunctivitis: Bacterial - ID the Invader

• 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.