How do you differentiate and treat viral vs bacterial conjunctivitis?

Differentiating and Treating Viral vs Bacterial Conjunctivitis

Viral conjunctivitis typically presents with watery discharge, follicular reaction on the inferior tarsal conjunctiva, and preauricular lymphadenopathy, while bacterial conjunctivitis characteristically shows mucopurulent discharge with matted eyelids and a papillary rather than follicular reaction. 1, 2

Key Clinical Differentiators

Viral Conjunctivitis Features

• Discharge type: Watery, clear discharge 2, 3
• Conjunctival reaction: Follicular pattern on inferior tarsal conjunctiva 1, 2
• Lymphadenopathy: Preauricular lymph node enlargement is common, particularly with adenoviral infections 1, 2
• Onset pattern: Abrupt onset, often starts unilateral but becomes sequentially bilateral 1, 2
• Associated symptoms: Concurrent upper respiratory infection frequently present 1, 2
• Distinctive findings: Subconjunctival hemorrhages, chemosis, eyelid swelling and erythema 1

Bacterial Conjunctivitis Features

• Discharge type: Purulent or mucopurulent with eyelids matted shut, especially upon waking 2, 3, 4
• Conjunctival reaction: Papillary rather than follicular 2
• Lymphadenopathy: Preauricular nodes less common unless caused by hypervirulent organisms like gonococcus 2
• Laterality: Can be unilateral or bilateral 2
• Associated symptoms: May occur with concurrent bacterial otitis media, sinusitis, or pharyngitis, particularly in children 2
• Clinical predictors: Mattering and adherence of eyelids on waking, lack of itching, and absence of prior conjunctivitis history strongly suggest bacterial etiology 4

Treatment Algorithm

For Viral Conjunctivitis

Most viral conjunctivitis requires only supportive care as it is self-limited, resolving within 5-14 days without antimicrobial treatment. 2

• Supportive measures: Artificial tears for symptomatic relief 2
• Symptom control: Topical antihistamines for comfort 2
• Cold compresses: For additional symptomatic relief 3
• Avoid antibiotics: Indiscriminate use of topical antibiotics should be avoided as viral conjunctivitis will not respond to antibacterial agents 2
• Patient education: Counsel about high contagiousness and minimize contact with others for 10-14 days from symptom onset 2
• Hand hygiene: Strict handwashing with soap and water, avoid sharing towels and pillows 2, 3

For Bacterial Conjunctivitis

Mild bacterial conjunctivitis is usually self-limited and may resolve without treatment, but moderate to severe cases benefit from a 5-7 day course of broad-spectrum topical antibiotics. 2

• Mild cases: Often self-limited; topical antibiotics may decrease duration but are not mandatory 2
• Moderate to severe cases: 5-7 day course of broad-spectrum topical antibiotic 2
• Antibiotic selection: No evidence demonstrates superiority of any particular topical antibiotic agent 2
• Common pathogens: Haemophilus influenzae (44.8%) and Streptococcus pneumoniae (30.6%) are most prevalent in pediatric populations 5
• Effective agents: Ciprofloxacin, chloramphenicol, and rifampin show activity against most prevalent pathogens 5
• Delayed prescribing: Has similar symptom control as immediate prescribing and is a reasonable strategy 3

Special Situations Requiring Different Management

Gonococcal Conjunctivitis

• Presentation: Marked eyelid edema, bulbar conjunctival injection, profuse purulent discharge, preauricular lymphadenopathy 2
• Risk: Can lead to corneal infiltrate, ulcer, and potentially perforation 2
• Treatment: Requires systemic antibiotics in addition to topical therapy 4

Chlamydial Conjunctivitis

• Management: Requires systemic treatment and evaluation of sexual partners 2
• Testing: PCR or immunofluorescent antibody testing for confirmation 1

Herpes Simplex Virus Conjunctivitis

• Presentation: Usually unilateral with vesicular rash or ulceration of eyelids, dendritic epithelial keratitis 2
• Treatment: Requires antiviral therapy (trifluridine preferred) 6
• Referral: Ophthalmology consultation advisable due to risk of recurrence with scarring and vision loss 6

Critical Pitfalls to Avoid

Never use topical corticosteroids unless herpetic infection is definitively ruled out, as steroids can cause devastating complications in HSV keratitis. 2, 6

• Avoid combination antibiotic-steroid preparations: These should never be used empirically 2, 6
• Don't miss severe viral conjunctivitis: Adenoviral conjunctivitis can present with marked eyelid swelling resembling preseptal cellulitis 7
• Recognize progression: Bacterial conjunctivitis can serve as a source for preseptal cellulitis when infection spreads to periorbital tissues 7
• Monitor for complications: Chronic or recalcitrant conjunctivitis may indicate underlying malignancy such as sebaceous or squamous cell carcinoma 2

Indications for Ophthalmology Referral

Refer immediately for visual loss, moderate to severe pain, severe purulent discharge, corneal involvement, conjunctival scarring, lack of response to therapy, recurrent episodes, history of HSV eye disease, or immunocompromised state. 2

• Neonatal conjunctivitis: Requires prompt evaluation and may need hospitalization for parenteral therapy 2
• Contact lens wearers: Should be treated with antibiotics due to risk of corneal infection 4
• Recent ocular surgery: Requires specialist evaluation 3
• Vesicular rash on eyelids or nose: Suggests herpes zoster and requires ophthalmology assessment 3