Summary

Viral Conjunctivitis is an acute inflammation of the conjunctiva caused by a viral infection, most commonly Adenovirus. It is highly contagious and typically presents with a watery (serous) discharge, conjunctival injection (red eye), and gritty discomfort. It often starts unilaterally and spreads to the other eye within days. Patients commonly have a history of recent Upper Respiratory Tract Infection (URTI) or contact with someone with pink eye. The condition is self-limiting, usually resolving within 2-3 weeks. Management is supportive (lubricants, hygiene, no antibiotics). It is critical to exclude Herpes Simplex Virus (HSV) keratitis (Dendritic Ulcer) in patients with vesicular rash, recurrent episodes, or unilateral pain/photophobia.

Key Facts

• Most Common Cause: Adenovirus.
• Transmission: Highly contagious. Direct contact, Fomites.
• Presentation: Watery discharge, Red eye, Gritty sensation, Pre-auricular lymphadenopathy.
• Associations: Recent URTI, Contact with infected person, Outbreaks (Schools, Pools).
• Course: Worsens over 3-5 days, resolves in 2-3 weeks.
• Treatment: Supportive (Lubricants, Hygiene). NO Antibiotics.
• Red Flag: Severe pain/photophobia -> Consider HSV Keratitis.

Clinical Pearls

"Watery = Viral, Purulent = Bacterial": Viral conjunctivitis produces a watery (serous) discharge. Thick purulent (yellow-green) discharge suggests bacterial infection.

"Pre-Auricular Lymph Nodes": Palpable pre-auricular lymph nodes are characteristic of viral (especially adenoviral) conjunctivitis.

"ALWAYS Exclude HSV": If there is vesicular rash, severe photophobia, recurrent unilateral eye disease, or dendritic ulcer on slit lamp -> Suspect HSV. Never give steroids without excluding HSV.

"No Antibiotics": Viral conjunctivitis is self-limiting. Antibiotic drops do not help and contribute to resistance.

Why This Matters Clinically

Viral conjunctivitis is extremely common and highly contagious. Recognising it avoids unnecessary antibiotic prescriptions. However, missing HSV keratitis can lead to blindness.

Systematic Examination

Fluorescein Staining (Critical)

• Self-Limiting: Resolves in 2-3 weeks.
• Vision: Usually preserved. Minor transient blur (discharge).
• Subepithelial Infiltrates (EKC): May cause glare/blur for months. Eventually resolves.

Key Guidelines

Scenario 1:

• Stem: A 25-year-old presents with a red, watery eye for 3 days. He had a cold last week. Pre-auricular lymph node is palpable. What is the most likely diagnosis?
• Answer: Viral Conjunctivitis (Probably Adenoviral).

Scenario 2:

• Stem: What is the key clinical feature differentiating viral from bacterial conjunctivitis?
• Answer: Discharge: Watery = Viral. Purulent = Bacterial. Pre-auricular lymph nodes = Viral.

Scenario 3:

• Stem: A patient with unilateral red eye has severe photophobia and vesicular lesions on the eyelid. What must you exclude?
• Answer: HSV Keratitis. Perform fluorescein staining – Look for Dendritic Ulcer.

What is Viral Conjunctivitis (Pink Eye)?

Viral conjunctivitis is an infection of the thin layer covering the white of your eye. It's usually caused by the same viruses that cause colds. It makes your eye red, watery, and uncomfortable.

Is it contagious?

Yes, very. It spreads easily through touching your eyes and then touching objects or other people. Wash your hands often and don't share towels.

How is it treated?

• It gets better on its own in 2-3 weeks.
• Use lubricating eye drops for comfort.
• No antibiotics (They don't work for viruses).
• Keep hands clean. Stay off work/school if you can.

Key Counselling Points

1. No Antibiotics Needed: "This is caused by a virus, so antibiotics won't help."
2. Highly Contagious: "Wash your hands frequently. Don't share towels."
3. Self-Limiting: "It will get better on its own in 2-3 weeks."
4. Red Flags: "Come back if you have severe pain, sensitivity to light, or blurred vision."

• "Pink Eye": Common layperson term for any red eye, most often used for infectious conjunctivitis.
• Adenovirus Discovery (1950s): Adenoviruses first isolated from adenoid tissue, hence the name.
• Epidemic Keratoconjunctivitis (EKC): Recognised as a distinct, highly contagious form with corneal involvement.