How should bilateral conjunctivitis be evaluated and managed?

Bilateral Conjunctivitis: Evaluation and Management

For bilateral conjunctivitis, perform fluorescein staining immediately to detect corneal involvement, assess discharge character and laterality, and rule out vision-threatening conditions before initiating treatment—viral etiology is most common and self-limited, but bacterial, gonococcal, and chlamydial causes require specific interventions. 1, 2

Immediate Red Flag Assessment

Perform these evaluations first to identify emergencies:

• Check visual acuity in both eyes—any decrease requires same-day ophthalmology referral 3
• Fluorescein staining is mandatory in every case, even without obvious corneal symptoms, to detect early keratitis or ulceration 3, 2
• Assess for moderate-to-severe pain—this indicates potential corneal involvement or more serious pathology 3
• Examine pupils for reactivity and afferent pupillary defect 3
• Look for proptosis or painful extraocular movements—these suggest orbital involvement requiring urgent evaluation 3
• Check for fever—particularly in neonates or with purulent discharge, as this may indicate systemic infection 2

History Elements That Guide Diagnosis

Obtain targeted information to differentiate etiologies:

• Character of discharge: Purulent/mucopurulent suggests bacterial; watery suggests viral; clear/stringy suggests allergic 1, 4
• Mattering and eyelid adherence on waking strongly indicates bacterial conjunctivitis 1, 4
• Itching as predominant symptom points to allergic etiology 1, 4
• Recent exposure to infected individuals or concurrent upper respiratory infection suggests adenoviral 1, 3
• Sexual activity history—gonococcal and chlamydial require systemic antibiotics 2, 4
• Contact lens wear—mandates treatment for bacterial conjunctivitis and evaluation for corneal ulcer 5, 4
• Neonatal age (especially 3-5 days for gonococcal, 5-19 days for chlamydial)—any purulent conjunctivitis is an emergency until these are ruled out 2

Physical Examination Priorities

Examine systematically for diagnostic clues:

• Preauricular lymphadenopathy—suggests viral (especially HSV) or Parinaud oculoglandular syndrome 1, 3
• Eyelid inspection for vesicles or dermatomal rash—HSV/VZV can progress to corneal scarring and perforation 3, 2
• Tarsal conjunctiva after lid eversion—follicles suggest viral; papillae suggest allergic or bacterial 1
• Bulbar conjunctiva follicles on semilunar fold—distinctive for chlamydial infection requiring systemic antibiotics 2
• Eyelid margin for dome-shaped umbilicated lesions—molluscum contagiosum 3
• Corneal examination with fluorescein—dendritic lesions indicate HSV keratitis; infiltrates may indicate bacterial or gonococcal involvement 3, 2

Differential Diagnosis by Presentation Pattern

Viral Conjunctivitis (Most Common Overall)

• Adenoviral presents with watery discharge, follicular reaction on inferior tarsal conjunctiva, chemosis, and may start unilaterally before becoming bilateral within days 1, 3
• Self-limited course with improvement in 5-14 days without treatment 3, 6
• Pharyngoconjunctival fever triad: fever, pharyngitis, bilateral conjunctivitis 2
• Monitor for progression to epidemic keratoconjunctivitis with subepithelial infiltrates causing long-term visual sequelae 2

Bacterial Conjunctivitis (Second Most Common Infectious)

• Bilateral green or yellow purulent discharge that mats eyelids on waking is hallmark 2
• Most uncomplicated cases resolve in 1-2 weeks without treatment 4, 7
• Topical antibiotics (fluoroquinolones, trimethoprim-polymyxin B) increase 7-day cure rate and allow earlier return to school/work 2
• Delayed prescribing strategy (wait 2-3 days before filling prescription) is preferred for uncomplicated cases 2

Gonococcal Conjunctivitis (Vision-Threatening Emergency)

• Marked eyelid edema, copious purulent discharge, preauricular lymphadenopathy 2
• Can cause corneal perforation within 24-48 hours if untreated 2
• Requires immediate systemic antibiotics in addition to topical therapy 2
• In neonates, can lead to septicemia, meningitis, and death 2
• Consider sexual abuse in children with this diagnosis 2

Chlamydial Conjunctivitis (Requires Systemic Treatment)

• Follicular conjunctivitis with distinctive follicles on bulbar conjunctiva and semilunar fold 2
• Topical antibiotics alone are insufficient—systemic treatment required 2
• In neonates (5-19 days old), associated with pneumonia in 50% of cases 2
• Trachoma is leading infectious cause of global blindness, presents with chronic follicular conjunctivitis and corneal pannus 2

Allergic Conjunctivitis (Up to 40% of Population)

• Itching is most consistent sign, bilateral presentation with watery discharge 4, 7
• Dark infraorbital swollen semicircles (allergic facies) and Morgan-Dennie lines on lower eyelid 3
• Treatment: topical antihistamines and mast cell stabilizers 4, 7

HSV/VZV Conjunctivitis (Can Progress to Blindness)

• HSV usually unilateral with watery discharge, mild follicular reaction, palpable preauricular lymph nodes 3, 2
• VZV presents with vesicular dermatomal rash or eyelid ulceration, severe pain 2
• Both can progress to keratitis, stromal keratitis, corneal scarring, perforation, uveitis 2
• Immediate ophthalmology referral required if vesicles present or fluorescein shows dendritic lesions 3

Management Algorithm

Step 1: Rule Out Emergencies (Immediate Referral Required)

• Visual acuity decrease 3
• Positive fluorescein staining showing corneal involvement 3, 2
• Moderate-to-severe pain 3
• Eyelid vesicles or dermatomal rash (HSV/VZV) 3
• Severe purulent discharge in sexually active adults or neonates (gonococcal) 2
• Any purulent conjunctivitis in neonates 2
• Immunocompromised patients 2

Step 2: Presumed Viral Conjunctivitis (No Red Flags)

• Cool compresses for symptomatic relief 3, 6
• No antibiotics needed—viral is self-limited 4, 7
• Mandatory follow-up in 3-4 days to assess improvement 3, 6
• Infection control: highly contagious, avoid sharing towels, frequent handwashing 1

Step 3: Bacterial Conjunctivitis (Purulent Discharge, No Red Flags)

• Delayed antibiotic prescribing preferred—advise waiting 2-3 days if symptoms don't improve 2
• Immediate topical antibiotics if rapid resolution desired for school/work return 2
• First-line agents: fluoroquinolones, trimethoprim-polymyxin B, aminoglycosides 2

Step 4: Special Populations Requiring Systemic Antibiotics

• Gonococcal: immediate systemic plus topical antibiotics 2
• Chlamydial: systemic antibiotics (topical alone insufficient) 2
• Contact lens wearers: always treat for bacterial and refer for corneal ulcer evaluation 5, 4
• Neonates: any purulent discharge requires cultures and systemic treatment until gonococcal/chlamydial ruled out 2

Step 5: Allergic Conjunctivitis

• Topical antihistamines and mast cell stabilizers 4, 7
• Systemic antihistamines if concurrent allergic rhinitis 5
• Topical lubricants for symptomatic relief 5

Critical Pitfalls to Avoid

• Never initiate systemic corticosteroids before ophthalmology consultation—can exacerbate herpetic infections 3
• Do not assume absence of discharge excludes infection—early viral or HSV may have minimal discharge 3
• Do not skip fluorescein staining—corneal involvement may not be clinically apparent 3, 2
• Do not treat presumed bacterial conjunctivitis in contact lens wearers without evaluating for corneal ulcer 5, 4
• Do not miss gonococcal conjunctivitis—can perforate cornea within 24-48 hours 2
• Do not forget to consider sexual abuse in children with gonococcal or chlamydial conjunctivitis 2

When to Send Cultures

• Gonococcal or chlamydial suspected (sexually active adults, neonates) 1
• Immunocompromised patients 1
• Severe or atypical presentations 1
• Failure to respond to initial treatment 1
• Recurrent conjunctivitis 1