What is the treatment for conjunctivitis (pink eye)?

Treatment of Conjunctivitis (Pink Eye)

Treatment depends entirely on identifying the underlying cause—viral, bacterial, or allergic—with most cases being self-limited but bacterial cases benefiting from topical antibiotics to shorten duration and reduce transmission. 1

Initial Diagnostic Approach

The key clinical features that differentiate etiologies include:

• Bacterial conjunctivitis: Mucopurulent discharge with eyelids matted shut upon waking, lack of itching, no history of prior conjunctivitis 2, 3
• Viral conjunctivitis: Watery discharge, often with preauricular lymphadenopathy, accounts for 80% of infectious cases 2, 4
• Allergic conjunctivitis: Itching is the hallmark symptom, bilateral presentation with watery/mucoid discharge, often with concurrent rhinitis 3, 5

Treatment by Etiology

Bacterial Conjunctivitis

For mild bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical antibiotic, with moxifloxacin 0.5% ophthalmic solution one drop three times daily being an effective first-line choice. 1, 6, 7

• Alternative antibiotics include other fluoroquinolones or aminoglycosides based on availability and cost 6
• Povidone-iodine 1.25% ophthalmic solution may be used when antibiotic access is limited 1
• Instruct patients to clean eyelids with warm water before applying medication 6
• Clinical cure rates with moxifloxacin range from 66-80% by days 5-9 7

For moderate to severe bacterial conjunctivitis (copious purulent discharge, marked inflammation, pain), obtain conjunctival cultures and Gram stain before initiating therapy. 1

• Consider MRSA, especially in nursing home residents or those with recurrent infections 1, 6
• Compounded vancomycin may be necessary for MRSA cases 1

For gonococcal conjunctivitis, systemic antibiotic therapy is mandatory with saline lavage for comfort. 1

• Obtain cultures immediately 1
• Treat sexual contacts and screen for other sexually transmitted infections 1
• Follow daily until resolution 1

For chlamydial conjunctivitis, systemic antibiotics are required as topical therapy alone is insufficient. 1

• More than 50% of infants have infection at other sites (nasopharynx, genital tract, lungs) 1
• Treatment failure occurs in up to 19% of cases, requiring re-evaluation 1
• Treat sexual contacts simultaneously 1

Viral Conjunctivitis

Viral conjunctivitis requires only supportive care with artificial tears, cold compresses, and topical antihistamines for symptom relief. 2, 3

• No specific antiviral treatment is indicated for adenoviral conjunctivitis 4
• Emphasize strict hand hygiene and avoid sharing towels/pillows to prevent transmission 8
• Most cases resolve spontaneously within 1-3 weeks 9

For herpes simplex viral conjunctivitis, oral antivirals are indicated: acyclovir 800 mg five times daily for 7 days, valacyclovir 1000 mg every 8 hours for 7 days, or famciclovir 500 mg three times daily for 7 days. 1

• Immunocompromised patients require more aggressive treatment 1
• Adjust doses in patients with impaired renal clearance 1
• Late sequelae include dry eye and neurotrophic keratitis 1

Allergic Conjunctivitis

Topical antihistamines with mast cell-stabilizing activity are first-line treatment for allergic conjunctivitis. 1, 3

• Preferably use single-dose or preservative-free formulations 5
• Artificial tears and cold compresses provide additional relief 2
• Allergen avoidance measures are essential 5
• Short courses of topical corticosteroids may be needed for severe flare-ups, requiring IOP monitoring 1, 5

When to Refer to Ophthalmology

Immediate ophthalmology referral is required for: 1, 2

• Visual loss or decreased vision
• Moderate to severe pain
• Corneal involvement (fluorescein staining positive)
• Severe purulent discharge
• Conjunctival scarring
• Lack of response to therapy after 3-4 days
• History of herpes simplex virus eye disease
• Immunocompromised patients
• Neonatal conjunctivitis

Follow-Up Recommendations

• Bacterial conjunctivitis: Return in 3-4 days if no improvement; resolution typically occurs within 7-10 days 1, 6
• Gonococcal conjunctivitis: Daily follow-up until resolution 1
• Chlamydial conjunctivitis: Re-evaluate after treatment due to high failure rates 1
• Patients can return to work/school after 24-48 hours of antibiotic treatment for bacterial cases 8

Critical Pitfalls to Avoid

• Do not use topical corticosteroids without ruling out herpes simplex virus, as this can worsen herpetic disease 1
• Do not prescribe contact lens wear during any active conjunctivitis 1, 7
• Do not assume all purulent discharge is bacterial—gonococcal and chlamydial infections require systemic therapy 1
• Do not ignore bilateral disease in elderly patients, as giant fornix syndrome may require prolonged systemic antibiotics 1, 6