This page is for adult patients. For pediatric patients, see: conjunctivitis (peds)


  • Most common cause of acute red eye
  • Viral infection is usual etiology

Conjunctivitis Types

Clinical Features

  • Injected conjunctiva with peri-limbal sparing
  • Rarely painful; more irritated

Conjunctivitis Images

Differential Diagnosis

Unilateral red eye

^Emergent diagnoses ^^Critical diagnoses

Bilateral red eyes


  • Typically clinical

Clinical diagnosis of conjunctivitis

Bacterial Viral Allergic
Bilateral 50% 25% Mostly
Discharge Mucopurulent Clear, Watery Cobblestoning, none
Redness Yes Yes Yes
Pruritis Rarely Rarely Yes
Additional Treatment: Antibiotics Treatment: Hygiene Seasonal


  • Viral infections - most common cause of conjunctivitis, but difficult to differentiate viral from bacterial
  • Some clinicians treat all presentations as bacterial conjunctivitis
  • Treatment considerations:
    • Ointments - soothing effect, but interfere with vision
    • Drops - no interference with vision

Antibiotics for Bacterial Causes

Bacterial Conjunctivitis

  • Counsel patient/family on importance of hand hygiene/avoiding touching face to prevent spread!
  • Apply warm or cool compresses (for comfort and cleansing) every 4 hours, followed by instillation of ophthalmic antibiotic solutions

These options do not cover gonococcal or chlamydial infections

  • Polymyxin B/Trimethoprim (Polytrim) 2 drops every 6 hours for 7 days OR
  • Erythromycin applied to the conjunctiva q6hrs for 7 days OR
  • Levofloxacin 0.5% ophthalmic solution 1-2 drops every 2 hours for 2 days THEN every 6 hours for 5 days OR
  • Moxifloxacin 0.5% ophthalmic 1-2 drops every 2 hours for 2 days THEN every 6 hours for 5 days OR
  • Gatifloxacin 0.5% ophthalmic solution 1-2 drops every 2 hours for 2 days THEN 1 drop every 6 hours for 5 days OR
  • Azithromycin 1% ophthalmic solution 1 drop BID for 2 days THEN 1 drop daily for 5 days
  • Chloramphenicol 0.5% ophthalmic solution 1 drop QID for 7 days

NB: levofloxacin is preferred for contact lens wearers for coverage of pseudomonas. Advise not to wear contacts for duration of treatment


  • Doxycycline 100mg PO BID for 7 days OR
  • Azithromycin 1g (20mg/kg) PO one time dose
  • Newborn Treatment: Azithromycin 20mg/kg PO once daily x 3 days or erythromycin PO 50 mg/kg/day in 4 divided doses for 14 days [1]
    • Disease manifests 5 days post-birth to 2 weeks (late onset)


  • Due to increasing resistance, CDC recommends dual therapy with Ceftriaxone and Azithromycin (even if patient is negative for Chlamydia).
  • Ceftriaxone 250mg IM one dose PLUS
  • Azithromycin 1g PO one dose
  • Newborn Treatment:
    • Prophylaxis: Erythromycin ophthalmic 0.5% x1
    • Disease manifests 1st 5 days post delivery (early onset)
    • Treatment Ceftriaxone 25-50mg IV or IM, max 125mg or cefotaxime single dose of 100 mg/kg (preferred if the patient has hyperbilirubinemia)
    • Also requires evaluation for disseminated disease (meningitis, arthritis, etc.)


  • Corticosteroids have no benefit and can cause sight threatening injuries, especially in HSV or fungal causes of red eye
  • Eye patching thought to exacerbate the infection


  • Outpatient treatment

See Also


  • Mahmood, Narang. Diagnosis & management of acute red eye. Emerg Med Clin N Am 2008;26
  1. Zikic A, Schünemann H, Wi T, Lincetto O, Broutet N, Santesso N. Treatment of Neonatal Chlamydial Conjunctivitis: A Systematic Review and Meta-analysis. J Pediatric Infect Dis Soc. 2018 Aug 17;7(3):e107-e115. doi: 10.1093/jpids/piy060. PMID: 30007329; PMCID: PMC6097578.