Conjunctivitis - Viral

Definition

Viral conjunctivitis is an inflammation of the conjunctiva caused by viral infections, most commonly adenoviruses, leading to red eyes, tearing, and discomfort. It is highly contagious and usually self-limiting.

Epidemiology

• Most common cause of acute infectious conjunctivitis worldwide
• Affects all age groups, more common in children and young adults
• Often occurs in outbreaks (schools, workplaces, swimming pools)
• Highly contagious via direct or indirect contact
• Seasonal peaks in late summer and fall for adenoviral infections

Etiology

• Adenoviruses are the most frequent cause
• Other viruses: enteroviruses, herpes simplex virus, varicella-zoster virus
• Transmission: direct contact with infected secretions, fomites, or respiratory droplets
• Risk factors: close contact environments, poor hand hygiene, swimming in contaminated water
• Contagious period: usually while tearing and redness are present

Pathophysiology

• Virus infects conjunctival epithelial cells causing cellular damage and inflammation
• Host immune response leads to conjunctival hyperemia, edema, and lymphocyte infiltration
• Follicular reaction and watery discharge develop due to lymphoid activation
• Associated preauricular lymphadenopathy due to lymphatic spread
• Self-limited in most cases due to effective immune clearance
• Secondary bacterial superinfection is rare but possible