EENT · PANCE / PANRE

Bacterial Conjunctivitis

Acute purulent conjunctival infection — most often self-limited; topical antibiotics shorten course.

Also known as: bacterial conjunctivitis, pink eye bacterial, mucopurulent conjunctivitis, hyperacute conjunctivitis

Overview

Acute infection of the conjunctiva characterized by mucopurulent discharge, conjunctival hyperemia, and crusted/'stuck shut' eyelids. Distinguished from viral and allergic conjunctivitis by the character of discharge and clinical context.

Epidemiology

Most common in children; ~50-75% of pediatric conjunctivitis is bacterial. Adults more often viral. Hyperacute (gonococcal) and chlamydial conjunctivitis affect sexually active adults and neonates of infected mothers.

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Risk factors

  • Direct contact with infected secretions
  • Contact lens wear (Pseudomonas, especially with poor hygiene or extended wear)
  • Recent upper respiratory infection (otitis-conjunctivitis syndrome — H. influenzae)
  • Crowded settings (schools, daycare)
  • Neonates born to mothers with untreated chlamydia or gonorrhea
  • Sexual transmission (gonococcal, chlamydial)
  • Immunocompromise

Pathophysiology

Bacterial inoculation of the conjunctival surface triggers a neutrophilic response, producing the characteristic purulent discharge. Common organisms in adults: Staphylococcus aureus, Streptococcus pneumoniae; in children: H. influenzae (often non-typeable), S. pneumoniae, M. catarrhalis. Pseudomonas aeruginosa in contact lens wearers. Neisseria gonorrhoeae produces hyperacute infection that can perforate the cornea within 24-48 h. Chlamydia trachomatis causes neonatal inclusion conjunctivitis and chronic adult inclusion conjunctivitis.

Clinical presentation

Symptoms

  • Eye redness, often beginning unilateral and spreading to fellow eye in 1-2 days
  • Mucopurulent (yellow/green) discharge throughout the day
  • Eyelids matted/stuck shut on awakening
  • Foreign body or 'gritty' sensation
  • Minimal or no itching (helps differentiate from allergic)
  • Mild discomfort; significant pain, photophobia, or vision loss suggests another diagnosis

Signs / physical exam

  • Diffuse bulbar and palpebral conjunctival injection
  • Purulent discharge — copious in hyperacute (gonococcal)
  • Lid edema and crusting
  • Cornea clear; visual acuity preserved
  • No preauricular lymphadenopathy (unlike viral or gonococcal)
  • Severe chemosis and lid edema in hyperacute gonococcal infection

Classic findings

Bilateral mucopurulent discharge with eyelids matted shut on awakening and normal vision in a school-age child.

Differential diagnosis

  • Viral conjunctivitis — Watery discharge, preauricular lymphadenopathy, recent URI; often bilateral after starting unilateral; supportive care
  • Allergic conjunctivitis — Itching is hallmark, bilateral, watery discharge, chemosis, atopic history; antihistamine/mast cell stabilizer drops
  • Hyperacute (gonococcal) conjunctivitis — Copious purulent discharge accumulating within minutes of wiping, severe lid edema, preauricular adenopathy; vision-threatening — Gram stain and culture, IM ceftriaxone PLUS topical therapy
  • Adult chlamydial inclusion conjunctivitis — Chronic >2 weeks, mucopurulent, follicular reaction, sexually active; NAAT; treat with azithromycin or doxycycline + partner therapy
  • Neonatal conjunctivitis (ophthalmia neonatorum) — Day of onset clues: chemical (day 0-1), gonococcal (2-5), chlamydial (5-14), HSV (1-2 weeks); gonococcal needs IV ceftriaxone — do not miss
  • Keratitis (bacterial, HSV, contact lens) — Pain, photophobia, decreased vision, corneal infiltrate on slit lamp; same-day ophthalmology
  • Iritis/uveitis — Pain, photophobia, ciliary flush, miotic pupil, cells/flare on slit lamp; ophthalmology referral
  • Acute angle-closure glaucoma — Severe pain, vomiting, halos around lights, mid-dilated fixed pupil, hazy cornea, IOP >40; emergency
  • Subconjunctival hemorrhage — Painless flat red blood under conjunctiva; no discharge or visual change; self-resolves

Diagnostic workup

Labs

  • Most cases: clinical diagnosis; no testing needed
  • Gram stain and culture if: hyperacute presentation, contact lens wearer, severe disease, neonate, immunocompromised, treatment failure
  • NAAT for Chlamydia trachomatis and Neisseria gonorrhoeae in adults with suspected STI conjunctivitis or in neonatal conjunctivitis

Imaging

  • Slit-lamp examination if any pain, photophobia, decreased vision, contact lens wear, or treatment failure — exclude keratitis or iritis
  • Fluorescein staining if corneal involvement suspected

Diagnostic algorithm

FeatureBacterialViralAllergic
DischargeMucopurulent (yellow-green)WateryStringy/mucoid, watery
ItchingMinimalMildHallmark (severe)
LateralityOften bilateralOften starts unilateralBilateral
Preauricular nodeAbsent (present in gonococcal)PresentAbsent
URI featuresSometimesOftenNo
Atopic historyYes
First-line treatmentTopical antibioticSupportive (cool compress)Antihistamine/MCS drops
Bedside differentiation of bacterial, viral, and allergic conjunctivitis.

Treatment

First-line

  • Most uncomplicated bacterial conjunctivitis is self-limited; topical antibiotics shorten course and reduce transmission
  • Topical ocular antibiotic — erythromycin ophthalmic ointment 0.5%, polymyxin B/trimethoprim drops, or moxifloxacin/ofloxacin drops × 5-7 days
  • Avoid topical aminoglycosides (gentamicin, tobramycin) as first line — corneal toxicity and limited gram-positive coverage
  • Frequent warm compresses to remove crusts; hand hygiene and dedicated towels to reduce spread
  • Contact lens wearers: discontinue lenses, use a topical fluoroquinolone (ciprofloxacin or moxifloxacin) for pseudomonal coverage, refer if any corneal involvement
  • Discard contaminated cosmetics and replace lenses/case after resolution

Second-line / adjunct

  • Hyperacute (gonococcal) conjunctivitis: ceftriaxone 1 g IM × 1 (or 25-50 mg/kg up to 125 mg IM/IV for neonates) PLUS saline irrigation PLUS topical erythromycin or ciprofloxacin; treat presumptively for chlamydia co-infection (azithromycin 1 g PO or doxycycline 100 mg BID × 7 days); ophthalmology referral
  • Adult chlamydial conjunctivitis: azithromycin 1 g PO × 1 OR doxycycline 100 mg PO BID × 7 days plus partner treatment
  • Neonatal chlamydial conjunctivitis: oral erythromycin × 14 days (topical does not eradicate nasopharyngeal carriage); monitor for pyloric stenosis
  • Neonatal gonococcal conjunctivitis: IV/IM ceftriaxone (single dose 25-50 mg/kg, max 125 mg) plus saline irrigation; admit
  • Same-day ophthalmology referral for any contact lens wearer with corneal involvement, suspected gonococcal infection, no improvement at 48 h, or vision-threatening signs

Complications

  • Corneal ulceration and perforation (hyperacute gonococcal or Pseudomonas in contact lens wearer)
  • Keratitis with permanent vision loss
  • Conjunctival scarring (chronic chlamydial — trachoma; leading global cause of preventable blindness)
  • Spread to fellow eye and close contacts
  • Pneumonia in neonates with chlamydial conjunctivitis (~10-20%)

PANCE pearls

  • Discharge type is a clinical clue (imperfect): purulent → bacterial; watery → viral; stringy/mucoid + itching → allergic.
  • Hyperacute purulent conjunctivitis = gonococcal until proven otherwise — sight-threatening; treat systemically with ceftriaxone and refer to ophthalmology.
  • All contact lens wearers with bacterial conjunctivitis require fluoroquinolone coverage for Pseudomonas and prompt ophthalmology evaluation.
  • Neonatal conjunctivitis timing: chemical (day 0-1), gonococcal (2-5), chlamydial (5-14), HSV (1-2 weeks).
  • Otitis-conjunctivitis syndrome in a child suggests H. influenzae — systemic amox-clav covers both.

References

  • AAO 2018 — American Academy of Ophthalmology. Conjunctivitis Preferred Practice Pattern. Ophthalmology 2019;126(1):P94-P169
  • CDC STI 2021 — Centers for Disease Control and Prevention. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 2021;70(4):1-187
  • AAP Red Book 2024 — American Academy of Pediatrics. Chlamydia trachomatis / Neisseria gonorrhoeae infections. In: Red Book 2024

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