Epidemic keratoconjunctivitis (EKC), pharyngeal conjunctival fever (PCF), and nonspecific follicular conjunctivitis caused by adenovirus

Adenovirus, a non-enveloped DNA virus, is a common cause of viral conjunctivitis, particularly presenting in three main clinical forms:

1. Epidemic keratoconjunctivitis (EKC)
2. Pharyngoconjunctival fever (PCF)
3. Simple follicular conjunctivitis

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🔹 Epidemic Keratoconjunctivitis (EKC)

• Caused by Adenovirus types 8, 19, and 37 (type 8 most common)
• Highly contagious, spreads through tears and eye secretions
• Begins in one eye, then affects the other with asymmetry
• Symptoms: redness, discharge, tearing, lymphadenopathy
• Corneal involvement: SPK → SEI → visual disturbance
• Steroid drops may reduce SEI severity if given early

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🔹 Pharyngoconjunctival Fever (PCF)

• Common in children, caused by Adenovirus type 3
• Triad: sore throat, conjunctivitis, fever
• Bilateral onset, resolves spontaneously in 7–14 days

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🔹 Simple Follicular Conjunctivitis

• Mildest form, usually subclinical or self-limiting
• Appears in late or mild stages of adenoviral infection

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📋 Adenovirus Conjunctivitis Comparison Table (English)

TypeEKCPCFSimple Follicular Conjunctivitis

Cause	Adenovirus 8, 19, 37	Adenovirus 3	Various adenoviruses
Laterality	Starts unilateral → spreads asymmetrically	Bilateral simultaneous onset	Mild and often unnoticed
Key Signs	SPK, SEI, pseudomembrane, lymphadenopathy	Sore throat + fever + follicular conjunctivitis	Mild follicles only
Course	~2–3 weeks, SEI may persist for months	Resolves in 7–14 days	Clears within days
Treatment	Artificial tears, topical steroids if needed	Supportive care	Usually no treatment required