What is the treatment for conjunctivitis?

Pertinent Negatives in Conjunctivitis

When evaluating conjunctivitis, the absence of visual loss, severe pain, corneal involvement, and purulent discharge indicates uncomplicated disease that can be managed in primary care without urgent ophthalmology referral. 1

Critical Red Flags to Rule Out

The following pertinent negatives help distinguish simple conjunctivitis from serious ocular conditions requiring immediate specialist evaluation:

Vision and Pain Assessment

• No visual loss - Visual impairment suggests corneal involvement, uveitis, or other serious pathology requiring ophthalmology referral 1, 2
• Absence of moderate-to-severe pain - Significant pain indicates potential keratitis, uveitis, acute angle-closure glaucoma, or corneal ulceration rather than simple conjunctivitis 1, 3
• No photophobia - Severe light sensitivity suggests corneal or intraocular inflammation beyond superficial conjunctivitis 1

Discharge Characteristics

• Not severe purulent discharge - Copious purulent discharge, especially bilateral, raises concern for gonococcal infection requiring systemic antibiotics and daily monitoring 2, 4
• Absence of severe matting - While mild matting occurs in bacterial conjunctivitis, severe adherence may indicate more aggressive infection 5

Structural and Corneal Findings

• No corneal involvement - Absence of corneal epithelial defects, infiltrates, or ulceration confirms disease limited to conjunctiva 1, 3
• No conjunctival scarring - Scarring suggests chronic disease, cicatricial conjunctivitis, or previous severe inflammation requiring specialist management 1, 3
• No membrane or pseudomembrane formation - These findings indicate severe adenoviral infection or other serious etiologies 1

Response to Treatment

• No lack of response to initial therapy - Failure to improve after 3-4 days of appropriate treatment warrants re-evaluation and possible ophthalmology referral 2, 4
• No recurrent episodes - Repeated conjunctivitis suggests underlying conditions like chronic blepharitis, dry eye, or immune-mediated disease 1, 3

Special History Considerations

• No history of HSV eye disease - Previous herpes simplex keratitis increases risk of recurrence and requires specialist management 1, 3
• No immunocompromised state - Immunosuppression increases risk of atypical or severe infections requiring closer monitoring 1, 3
• No contact lens wear - Contact lens-related conjunctivitis may involve Pseudomonas or Acanthamoeba, requiring specific antibiotic coverage 4
• No recent ocular surgery - Post-surgical conjunctivitis requires different management considerations 6

Clinical Decision Algorithm

If ALL pertinent negatives are present:

• Mild-to-moderate bacterial conjunctivitis can be treated with topical broad-spectrum antibiotics (bacitracin or erythromycin) for 5-7 days 3, 4, 7, 8
• Viral conjunctivitis requires only supportive care with artificial tears and cold compresses 2, 4
• Allergic conjunctivitis responds to topical antihistamines with mast cell-stabilizing properties 2, 4

If ANY red flag is present:

• Immediate ophthalmology referral is indicated 1, 2, 3
• Do not delay referral for culture results or trial of therapy 1

Common Pitfalls to Avoid

• Indiscriminate corticosteroid use - Topical steroids can prolong adenoviral infections and worsen HSV infections; avoid unless under ophthalmology guidance 2, 4
• Missing sexually transmitted infections - Gonococcal and chlamydial conjunctivitis require systemic antibiotics, not just topical therapy 2, 4
• Overlooking neonatal conjunctivitis - All neonatal cases require hospitalization and systemic treatment 2, 4
• Failing to assess for child abuse - Sexually transmitted conjunctivitis in children mandates consideration of abuse and appropriate reporting 1