Conjunctivitis is one of the most common causes of red-eye and affects patients of all ages and socioeconomic class. Viral conjunctivitis is responsible for the majority of infectious conjunctivitis, accounting for up to 75% of cases and is more prevalent in the summer.

What is conjunctivitis?

Conjunctivitis, also known as "pink eye", is inflammation of the conjunctiva. The three most common causes of conjunctivitis are viral, allergic, and bacterial, and the majority of cases are caused by adenovirus.

What causes viral conjunctivitis?

Between 65% and 90% of cases of viral conjunctivitis are caused by adenoviruses

Other viruses that can be responsible for conjunctival infection include herpes simplex virus (HSV), varicella-zoster virus (VZV), picornavirus (enterovirus 70, Coxsackie A24), poxvirus (molluscum contagiosum, vaccinia), and human immunodeficiency virus (HIV).

Viral conjunctivitis is highly contagious, usually for 10-12 days from onset as long as the eyes are red and tearing.

What are the symptoms and signs of viral conjunctivitis?

History and physical examination are, essential in the diagnosis of conjunctivitis, and in determining the cause and therefore treatment of the condition.

The diagnosis of viral conjunctivitis is based on clinical and laboratory signs. 

Viral conjunctivitis typically begins in one eye and then spreads to the other. 

The main symptoms of viral conjunctivitis include: 

• Pinkness or, often, intense redness of the eye
• Sudden onset foreign body sensation
• Burning, a sensation of grittiness
• Mild pain, itching or discomfort in the eye
• Watery discharge from the eye
• Swollen and/or reddened eyelids

Those presenting with viral conjunctivitis usually have a recent history of upper respiratory tract infection or recent contact with a sick individual.

Visual acuity is usually at or near their baseline vision.

The conjunctiva can also be edematous. 

The cornea can have subepithelial infiltrates that can decrease vision and cause light sensitivity.

May have tender preauricular lymphadenopathy.

How viral conjunctivitis is diagnosed?

Labs and cultures are rarely indicated to confirm the diagnosis of conjunctivitis.

Laboratory testing is typically not indicated unless the symptoms are not resolving and the infection last longer than 4 weeks. 

Eyelid cultures and cytology are usually reserved for cases of recurrent conjunctivitis, those resistant to treatment, suspected gonococcal or chlamydial infection, suspected infectious neonatal conjunctivitis, and adults presenting with severe purulent discharge.

Rapid antigen testing is available for adenoviruses and can be used to confirm suspected viral causes of conjunctivitis to prevent unnecessary antibiotic use. 

How is viral conjunctivitis treated?

Viral conjunctivitis due to adenoviruses is self-limiting, lasting 10 to 14 days.

Symptoms often worsen for 3–5 days, with gradual resolution over 1–2 weeks. Treatment should target symptomatic relief.

Symptomatic treatments include:

• Cold compresses with a wet washcloth several times per day
• Artificial tears for lubrication four times a day
• Topical vasoconstrictors (eg phenylephrine 0.12% drops)
• Topical antihistamines may be used for severe itching
• Povidone-iodine eye drop, a non-specific disinfectant, is a promising new treatment for adenoviral conjunctivitis (a Single Administration of 5% Povidone-Iodine could reduce viral load and hasten the improvement of clinical signs and symptoms)
• Systemic analgesics for pain relief

Antibiotics are not recommended for the treatment of viral conjunctivitis.

Steroids should be reserved for patients with decreased vision due to their subepithelial infiltrates or severe conjunctival injection causing more the expected discomfort.

Herpes infections are treated with topical and systemic acyclovir and other antiviral agents. 

Molluscum contagiosum is treated by physicial removal of the skin papule/s.

Antiviral medication for viral conjunctivitis

Sometimes, topical or oral antiviral medication may be recommended. This is typically reserved for cases of viral conjunctivitis which: 

·       Are severe, such as those caused by the herpes simplex virus or varicella-zoster virus

·       Are very long-lasting

·       Occur in newborn babies

·       Occur in people who have weakened immune systems

Any patient with moderate to severe pain, vision loss, corneal involvement, severe purulent discharge, conjunctival scarring, recurrent episodes, lack of response to therapy, or herpes simplex keratitis should receive a prompt referral to an ophthalmologist.

In addition, those requiring steroids, contact lens wearers, and patients with photophobia should also get a referral.

Doctors Liked to Read More