What is the appropriate treatment for pink eye (conjunctivitis)?

Treatment of Pink Eye (Conjunctivitis)

Treatment depends critically on identifying the etiology—viral conjunctivitis requires only supportive care, bacterial conjunctivitis may benefit from antibiotics but often resolves spontaneously, allergic conjunctivitis responds to topical antihistamines, and herpes simplex requires antiviral therapy. 1

Diagnostic Approach

The key is differentiating between viral, bacterial, allergic, and other causes based on clinical presentation:

• Viral conjunctivitis: Watery discharge, burning/gritty sensation, often bilateral, may have preauricular lymphadenopathy 2, 3
• Bacterial conjunctivitis: Mucopurulent discharge with eyelids matted shut on waking, more common in children, lack of itching 2, 3
• Allergic conjunctivitis: Bilateral itching (most consistent sign), watery discharge, chemosis, seasonal pattern 1, 3
• HSV conjunctivitis: May have vesicular lesions, dendritic keratitis on examination 1

Treatment by Etiology

Viral Conjunctivitis (Most Common Overall)

Supportive care only—antibiotics should be avoided as they provide no benefit and carry risks. 1, 3

• Artificial tears, cold compresses, and topical antihistamines for symptom relief 2
• Strict hand hygiene to prevent transmission 2
• Most cases self-resolve in 2-3 weeks 1
• Topical corticosteroids may be considered for severe cases with marked chemosis, eyelid swelling, epithelial sloughing, or membranous conjunctivitis, but require close monitoring for IOP elevation and cataract formation 1
• For corneal subepithelial infiltrates causing vision symptoms: topical corticosteroids at minimum effective dose (fluorometholone or loteprednol preferred) or cyclosporine 0.05-1% 1
• Follow-up if symptoms persist beyond 2-3 weeks or if pain/vision loss develops 1

Bacterial Conjunctivitis

Delayed antibiotic prescribing achieves similar symptom control as immediate prescribing, since most cases resolve spontaneously in 1-2 weeks. 2, 3

• 55.5% of placebo-treated patients achieve spontaneous clinical resolution by days 4-9 versus 68.2% with antibiotics 4
• Antibiotics modestly improve clinical cure (RR 1.26) and microbiological cure (RR 1.53) compared to placebo 4
• Antibiotics reduce persistent infection by 27% and allow earlier return to work/school 4
• Immediate antibiotic treatment is indicated for: contact lens wearers (risk of corneal ulcer), gonorrhea/chlamydia (requires systemic plus topical antibiotics), and severe cases 2, 3
• No serious systemic side effects reported with topical antibiotics 4

Allergic Conjunctivitis

Topical antihistamines with mast cell-stabilizing activity are first-line treatment. 2, 5

• Dual-acting agents (antihistamine + mast cell stabilizer) are most effective 5
• Topical lubricants and cold compresses for additional symptom relief 5
• Allergen avoidance when possible 5
• Systemic antihistamines may be added for inadequate control 6

Herpes Simplex Virus Conjunctivitis

Antiviral therapy is required to prevent progression and complications. 1

• Topical options: Ganciclovir 0.15% gel 3-5 times daily (less toxic) OR trifluridine 1% solution 5-8 times daily (causes epithelial toxicity after 2 weeks) 1
• Oral antivirals: Acyclovir 200-400 mg five times daily, valacyclovir 500 mg 2-3 times daily, or famciclovir 250 mg twice daily 1
• Combination topical + oral therapy is most effective for HSV blepharoconjunctivitis 1
• Avoid topical corticosteroids—they potentiate HSV epithelial infections 1
• Follow-up within 1 week to assess response 1
• Neonates require urgent pediatric consultation due to risk of life-threatening systemic HSV infection 1

Critical Red Flags Requiring Ophthalmology Referral

Immediate referral is indicated for: 2

• Severe pain or decreased vision
• Recent ocular surgery
• Vesicular rash on eyelids or nose (herpes zoster ophthalmicus)
• Neonatal conjunctivitis
• Immunocompromised state
• History of rheumatologic disease
• Contact lens wearer with suspected bacterial conjunctivitis

Common Pitfalls

• Do not prescribe antibiotics for viral conjunctivitis—this increases antibiotic resistance without benefit 1, 3
• Do not use topical corticosteroids for HSV conjunctivitis—this worsens epithelial disease 1
• If prescribing prolonged topical corticosteroids for any indication, monitor IOP and perform pupillary dilation to screen for glaucoma and cataract 1
• Corticosteroids may prolong viral shedding in adenoviral conjunctivitis 1