What is the appropriate management of conjunctivitis in an adult patient who does not use contact lenses?

Treatment of Conjunctivitis in Adults Without Contact Lenses

For mild bacterial conjunctivitis in immunocompetent adults, observation without antibiotics is a valid first-line approach, though a 5-7 day course of broad-spectrum topical antibiotics (such as moxifloxacin 0.5% three times daily) can shorten symptom duration by 2-5 days if treatment is desired. 1, 2

Diagnostic Approach: Determining the Etiology

The key to appropriate management is distinguishing between bacterial, viral, and allergic causes, as treatment differs fundamentally for each:

History Elements to Assess:

• Discharge character: Purulent/mucopurulent discharge with eyelids matted shut upon waking strongly suggests bacterial etiology 1, 3, 4
• Itching: Severe itching is the most consistent sign of allergic conjunctivitis 1, 4
• Watery discharge: More common in viral and allergic conjunctivitis 3
• Exposure history: Recent contact with infected individuals (viral), allergen exposure (allergic), or sexual contact (gonococcal/chlamydial) 1
• Systemic symptoms: Upper respiratory infection symptoms suggest viral etiology; genitourinary discharge suggests gonococcal/chlamydial 1

Physical Examination Findings:

• Visual acuity measurement is mandatory at every visit 1
• Preauricular lymphadenopathy suggests viral conjunctivitis 1
• Follicular reaction on conjunctiva indicates viral etiology 5
• Slit-lamp biomicroscopy to evaluate for corneal involvement 1

Treatment by Etiology

Mild Bacterial Conjunctivitis

For mild bacterial conjunctivitis, you have two evidence-based options:

1. Observation without antibiotics: Approximately 64% of cases resolve spontaneously by days 6-10 without treatment 1, 2

2. Topical antibiotics: Apply broad-spectrum topical antibiotic 1-3 times daily for 5-7 days directly into the conjunctival sac 1

   • Preferred agents: Moxifloxacin 0.5% three times daily provides superior gram-positive coverage including some MRSA strains 1, 5
   • Alternative agents: Ofloxacin 0.3%, ciprofloxacin, gentamicin, or tetracycline four times daily if fluoroquinolones are unavailable 1, 5
   • Resource-limited settings: Povidone-iodine 1.25% ophthalmic solution may be as effective as topical antibiotics 1, 2

Benefits of topical antibiotics include:

• Earlier clinical remission at days 2-5 (68% cure rate vs 55% with placebo) 1, 5
• Reduced transmissibility and earlier return to work/school 2
• No single antibiotic shows superiority, so choose based on convenience and cost 1, 5

Moderate to Severe Bacterial Conjunctivitis

Characterized by copious purulent discharge, pain, and marked inflammation:

• Obtain conjunctival cultures and Gram staining before initiating treatment, especially if gonococcal infection or MRSA is suspected 1, 5
• Initiate empiric broad-spectrum topical antibiotics while awaiting culture results 2
• Consider MRSA coverage: If no response within 48-72 hours, compounded topical vancomycin may be required 1, 5

Gonococcal or Chlamydial Conjunctivitis

Systemic antibiotic therapy is mandatory; topical treatment alone is insufficient:

• Gonococcal: Ceftriaxone 250 mg IM single dose plus azithromycin 1 g oral single dose 5, 2
• Chlamydial: Azithromycin 1 g oral single dose OR doxycycline 100 mg oral twice daily for 7 days 5, 2
• Daily monitoring until resolution is necessary for gonococcal conjunctivitis to prevent corneal perforation 1, 5
• Evaluate for concurrent genital infections and treat sexual partners 1, 5

Viral Conjunctivitis

No proven effective treatment for adenovirus eradication; provide symptomatic care:

• Supportive measures: Refrigerated preservative-free artificial tears four times daily, cold compresses, and topical antihistamines for comfort 1, 5
• Avoid antibiotics due to potential adverse effects without benefit 1, 5
• Strict hand hygiene with soap and water to prevent transmission 5, 2

For HSV conjunctivitis specifically:

• Topical antivirals: Ganciclovir 0.15% gel OR trifluridine 1% solution 1, 5
• Oral antivirals: Acyclovir, valacyclovir, or famciclovir may also be used 5
• Never use topical corticosteroids without antiviral coverage, as they potentiate HSV infection 1, 5

Allergic Conjunctivitis

Topical antihistamines with mast cell-stabilizing activity are first-line treatment:

• First-line: Second-generation topical antihistamine/mast cell stabilizers 1, 5
• Adjunctive measures: Cold compresses, refrigerated preservative-free artificial tears, sunglasses as allergen barrier 5
• Second-line: Brief 1-2 week course of low side-effect profile topical corticosteroids (fluorometholone, rimexolone, or loteprednol) if symptoms persist, with monitoring of intraocular pressure 5

Critical Red Flags Requiring Immediate Ophthalmology Referral

Refer immediately for any of the following:

• Visual loss or decreased vision 1, 2
• Moderate or severe pain (beyond mild irritation) 1, 2
• Severe purulent discharge suggesting gonococcal infection 1, 2
• Corneal involvement (opacity, infiltrate, or ulcer) 1, 2
• Conjunctival scarring or membrane formation 1, 2
• Lack of response to therapy after 3-4 days 1, 2
• Recurrent episodes despite treatment 1, 2
• History of HSV eye disease 1, 2
• Immunocompromised status 1, 2

Follow-Up Protocol

• For bacterial conjunctivitis: Return in 3-4 days if no improvement 1, 5
• For gonococcal conjunctivitis: Daily visits until resolution 1, 5
• All follow-up visits should include interval history, visual acuity measurement, and slit-lamp biomicroscopy 1
• Complete resolution typically occurs within 7-10 days with appropriate treatment 1, 2
• If symptoms persist despite appropriate therapy, obtain conjunctival cultures to rule out MRSA 1

Common Pitfalls to Avoid

• Delayed referral for gonococcal conjunctivitis leads to poor outcomes including corneal perforation; systemic antibiotics and daily monitoring are mandatory 1, 5
• Using topical corticosteroids in HSV conjunctivitis without antiviral coverage potentiates infection and can cause corneal perforation 1, 5
• Prescribing antibiotics for viral conjunctivitis causes unnecessary adverse effects and promotes antimicrobial resistance 1, 5
• Prescribing systemic antibiotics for uncomplicated bacterial conjunctivitis is inappropriate; topical therapy or observation is sufficient 2
• Failure to consider sexual abuse in children with gonococcal or chlamydial conjunctivitis 1, 5
• Failing to treat sexual contacts in chlamydial or gonococcal cases 1

Return to Work/School

• Patients may return after 24-48 hours of antibiotic treatment if symptoms are improving 2
• For viral conjunctivitis: Avoid close contact for 7-14 days from symptom onset 5