What is the recommended treatment for a patient presenting with conjunctivitis (pink eye)?

Treatment of Conjunctivitis

Treatment of conjunctivitis must be directed at the specific etiology—viral conjunctivitis requires only supportive care without antibiotics, bacterial conjunctivitis benefits from topical antibiotics in moderate-to-severe cases, and allergic conjunctivitis responds to topical antihistamines with mast cell-stabilizing activity. 1

Diagnostic Approach: Determining the Etiology

Before initiating treatment, distinguish between viral, bacterial, and allergic causes based on these key clinical features:

Viral Conjunctivitis

• Watery discharge with follicular reaction on inferior tarsal conjunctiva 1
• Preauricular lymphadenopathy (especially with adenovirus) 1
• Often starts unilateral but becomes sequentially bilateral 1
• Concurrent upper respiratory infection common 1
• May have subconjunctival hemorrhages 1

Bacterial Conjunctivitis

• Mucopurulent or purulent discharge with matted eyelids upon waking 1, 2
• Papillary (not follicular) conjunctival reaction 1
• Lack of itching 2
• May be unilateral or bilateral 1
• Preauricular lymphadenopathy less common unless hypervirulent organisms 1

Allergic Conjunctivitis

• Itching is the most consistent and distinguishing feature 1, 2
• Bilateral presentation 1
• Watery discharge with mild mucous component 1
• History of atopy, asthma, or eczema 1
• Chemosis and eyelid edema 3
• No preauricular lymphadenopathy 1

Treatment by Etiology

Viral Conjunctivitis: Supportive Care Only

Do not prescribe antibiotics for viral conjunctivitis—they provide no benefit and cause unnecessary toxicity and resistance. 1, 4

Supportive measures include:

• Artificial tears (refrigerated, preservative-free) every 2 hours for symptomatic relief 1, 4
• Cold compresses for comfort 1, 5
• Topical antihistamines for symptomatic relief of itching 1
• Patient education about high contagiousness for 10-14 days from symptom onset 1

Infection control is critical:

• Strict hand hygiene with soap and water 1, 4
• Avoid sharing towels, pillows, or personal items 1
• Consider work-from-home arrangements for 10-14 days 6
• Disinfect surfaces with 1:10 dilution of household bleach 7, 6

When to consider topical corticosteroids (requires ophthalmology consultation):

• Severe cases with marked chemosis, lid swelling, epithelial sloughing, or membranous conjunctivitis 1, 4
• Critical warning: Corticosteroids prolong adenoviral infections and worsen HSV infections 7, 1
• Requires close monitoring of intraocular pressure and periodic pupillary dilation 1, 4

Special consideration for HSV conjunctivitis:

• Topical ganciclovir 0.15% gel or trifluridine 1% solution 4
• Oral antivirals (acyclovir, valacyclovir, or famciclovir) 4
• Never use topical corticosteroids without antiviral coverage 4

Bacterial Conjunctivitis: Selective Antibiotic Use

Mild bacterial conjunctivitis is often self-limited and may resolve without antibiotics, but topical antibiotics shorten disease duration and allow earlier return to work/school. 1, 2

For moderate-to-severe bacterial conjunctivitis:

• 5-7 day course of broad-spectrum topical antibiotic 1, 4
• No specific antibiotic is superior—choose based on convenience and cost 1, 4

Antibiotic options:

• Topical fluoroquinolones (moxifloxacin, levofloxacin, gatifloxacin, ciprofloxacin, besifloxacin) provide excellent coverage against common pathogens including S. aureus, S. pneumoniae, and H. influenzae 4
• Erythromycin ointment 1, 8
• Polymyxin B/trimethoprim drops 1
• Bacitracin ointment 1-3 times daily 9

Critical red flags requiring systemic antibiotics and urgent referral:

Gonococcal conjunctivitis:

• Marked eyelid edema, severe purulent discharge, preauricular lymphadenopathy 1
• Can cause corneal perforation 1, 4
• Requires systemic treatment: ceftriaxone 250 mg IM single dose + azithromycin 1 g oral single dose 4
• Daily monitoring until resolution 4
• Treat sexual partners 4

Chlamydial conjunctivitis:

• Requires systemic treatment (topical therapy alone is inadequate) 1, 4
• Azithromycin 1 g oral single dose OR doxycycline 100 mg oral twice daily for 7 days 4
• Treat sexual partners 4
• Consider sexual abuse in children 4

Neonatal conjunctivitis:

• Requires systemic treatment coordinated with pediatrician 4
• Gonococcal: ceftriaxone 25-50 mg/kg IV or IM single dose 4
• Chlamydial: erythromycin base or ethylsuccinate 50 mg/kg/day oral divided into 4 doses for 14 days 4, 8
• Monitor for infantile hypertrophic pyloric stenosis with erythromycin in infants <6 weeks 4

Allergic Conjunctivitis: Antihistamines and Environmental Modifications

First-line treatment is topical antihistamines with mast cell-stabilizing activity (olopatadine, ketotifen). 1, 4

Environmental and supportive measures:

• Wear sunglasses as barrier to airborne allergens 7, 1
• Cold compresses 7, 1
• Refrigerated artificial tears 7, 1
• Avoid eye rubbing 7
• Hypoallergenic bedding, frequent clothes washing, showering before bedtime 7

Escalation for persistent symptoms:

• Brief 1-2 week course of topical corticosteroids with low side-effect profile (e.g., loteprednol etabonate) 7, 1, 10
• Monitor intraocular pressure if using corticosteroids 1, 4

Avoid chronic use of topical vasoconstrictors—they cause rebound vasodilation. 7, 6

Red Flags Requiring Urgent Ophthalmology Referral

Refer immediately for: 1, 4

• Visual loss or decreased vision
• Moderate or severe pain
• Severe purulent discharge
• Corneal involvement (infiltrate, ulcer, opacity)
• Conjunctival scarring
• Lack of response to therapy
• History of HSV eye disease
• Immunocompromised state
• Suspected gonococcal or chlamydial infection

Common Pitfalls to Avoid

• Never prescribe antibiotics indiscriminately for viral conjunctivitis—this promotes resistance and causes toxicity 7, 1, 4
• Never use topical corticosteroids without ophthalmology guidance—they prolong adenoviral infections, worsen HSV infections, and can cause elevated intraocular pressure and cataracts 7, 1, 4
• Never miss gonococcal conjunctivitis—delayed treatment leads to corneal perforation and vision loss 1, 4
• Never use topical therapy alone for chlamydial or gonococcal conjunctivitis—systemic antibiotics are mandatory 1, 4
• Never ignore the possibility of sexual abuse in children with gonococcal or chlamydial conjunctivitis 4
• Avoid contact lens wear during any infectious conjunctivitis 4