Pink Eye Differential and Initial Management
Immediate Clinical Differentiation
The initial management of conjunctivitis depends on accurately distinguishing between viral, bacterial, and allergic etiologies through specific clinical features, with viral conjunctivitis being the most common cause requiring only supportive care, while bacterial cases may benefit from antibiotics in moderate-to-severe presentations. 1, 2
Key Distinguishing Clinical Features
Viral Conjunctivitis:
- Abrupt onset, typically starting unilateral but becoming sequentially bilateral within days 2
- Watery, serofibrinous discharge (not purulent) 3, 4
- Follicular reaction on the inferior tarsal conjunctiva (small, dome-shaped elevations) 1, 2
- Preauricular lymphadenopathy (swollen lymph node in front of the ear) 1, 2
- Often accompanied by concurrent upper respiratory infection symptoms 2
- May present with subconjunctival hemorrhages, chemosis, and eyelid swelling 2
Bacterial Conjunctivitis:
- Mucopurulent or purulent discharge with eyelids matted shut upon waking 3, 5
- Papillary reaction (rather than follicular) on tarsal conjunctiva 2
- Can be unilateral or bilateral 2
- Preauricular lymphadenopathy is uncommon unless caused by hypervirulent organisms 2
- More common in children than adults 3, 6
Allergic Conjunctivitis:
- Bilateral presentation with intense itching (most consistent sign) 5, 7
- Watery discharge with mucoid component 7
- Chemosis and eyelid edema 7
- Seasonal pattern or exposure to known allergens 8
- Papillary reaction on tarsal conjunctiva 8
Initial Management by Etiology
Viral Conjunctivitis Management
Avoid antibiotics entirely, as they provide no benefit and may cause toxicity. 8, 1
Supportive care measures:
- Artificial tears (refrigerated for additional cooling comfort) to dilute viral particles and provide symptomatic relief 1, 9, 3
- Cold compresses to reduce inflammation 8, 9
- Topical antihistamines for itching and discomfort 8, 1, 9
- Oral analgesics for pain management 8, 9
Critical infection control education:
- Patients must minimize contact with others for 10-14 days from symptom onset in the last affected eye 1, 9
- Strict hand hygiene with soap and water 2
- Avoid sharing towels, pillows, and personal items 2
- Adenovirus can survive for weeks on surfaces without proper disinfection 9
When to consider topical corticosteroids (use with extreme caution):
- Only for severe cases with marked chemosis, lid swelling, epithelial sloughing, or membranous conjunctivitis 8, 1
- Requires close follow-up with regular IOP monitoring and pupillary dilation to evaluate for glaucoma and cataract 8, 1
- Use lowest effective dose and taper slowly 8, 9
- Prefer corticosteroids with poor ocular penetration (fluorometholone, rimexolone, or loteprednol) to minimize side effects 8, 9
- Warning: Corticosteroids may prolong viral shedding and worsen HSV infections 8
Bacterial Conjunctivitis Management
Mild cases are self-limited and may resolve without antibiotics, though treatment may shorten duration. 2, 5
For moderate-to-severe bacterial conjunctivitis:
- Prescribe a 5-7 day course of broad-spectrum topical antibiotic 2
- No evidence demonstrates superiority of any particular topical antibiotic agent 2
- Consider delayed antibiotic prescribing strategy, which has similar symptom control as immediate prescribing 3
Special bacterial considerations requiring systemic treatment:
- Gonococcal conjunctivitis (marked lid edema, purulent discharge, risk of corneal perforation) requires systemic antibiotics 2
- Chlamydial conjunctivitis requires systemic treatment and evaluation of sexual partners 2
- Contact lens wearers must always be treated and referred to evaluate for corneal ulcers 6
Allergic Conjunctivitis Management
Environmental modifications:
- Wear sunglasses as barrier to airborne allergens 8
- Cold compresses and refrigerated artificial tears 8
- Avoid eye rubbing 8
- Hypoallergenic bedding, frequent clothes washing, showering before bedtime 8
Pharmacologic treatment:
- Topical antihistamines with mast cell-stabilizing activity are first-line treatment 8, 3, 5
- Over-the-counter topical antihistamine/vasoconstrictor agents for mild cases 8
- Second-generation topical histamine H1-receptor antagonists are more effective 8
- Avoid chronic use of vasoconstrictors due to rebound vasodilation 8
- For persistent symptoms, add brief course (1-2 weeks) of topical corticosteroids with low side effect profile 8
- Avoid oral antihistamines when possible, as they may worsen dry eye and actually worsen allergic conjunctivitis 8
Critical Red Flags Requiring Immediate Ophthalmology Referral
Refer urgently for any of the following: 1, 2, 3
- Visual loss or decreased vision
- Moderate or severe pain
- Corneal involvement (opacity, infiltrate, or ulcer)
- Lack of response to therapy
- History of HSV eye disease
- Immunocompromised status
- Recent ocular surgery
- Vesicular rash on eyelids or nose
- Neonatal conjunctivitis (requires prompt evaluation and possible hospitalization)
Common Pitfalls to Avoid
Indiscriminate antibiotic use: Antibiotics cause toxicity in viral cases and provide no benefit, delaying proper diagnosis 8, 1, 2
Inappropriate corticosteroid use: Corticosteroids prolong adenoviral infections and can worsen HSV infections, potentially causing corneal perforation 8
Inadequate patient education: Failure to educate about contagiousness leads to community spread and workplace/school outbreaks 1, 9
Missing serious underlying conditions: Chronic or recalcitrant conjunctivitis may indicate underlying malignancy (sebaceous or squamous cell carcinoma) 2
Follow-Up Recommendations
For viral conjunctivitis:
- Patients with severe disease should be re-evaluated within 1 week 8, 1
- Patients not on corticosteroids should return if symptoms persist beyond 2-3 weeks 8, 1
- Monitor for development of subepithelial infiltrates (typically occur 1+ weeks after onset) 8
For patients on topical corticosteroids: