Merck Manual

Please confirm that you are a health care professional

honeypot link

Viral Conjunctivitis

By

Melvin I. Roat

, MD, FACS, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision Apr 2021| Content last modified Apr 2021
Click here for Patient Education
Topic Resources

Viral conjunctivitis is a highly contagious acute conjunctival infection usually caused by an adenovirus. Symptoms include irritation, photophobia, and watery discharge. Diagnosis is clinical; sometimes viral cultures or immunodiagnostic testing is indicated. Infection is self-limited, but severe cases sometimes require topical corticosteroids.

Etiology of Viral Conjunctivitis

Conjunctivitis may accompany the common cold and other systemic viral infections (especially measles Measles Measles is a highly contagious viral infection that is most common among children. It is characterized by fever, cough, coryza, conjunctivitis, an enanthem (Koplik spots) on the oral mucosa... read more Measles , but also chickenpox Chickenpox Chickenpox is an acute, systemic, usually childhood infection caused by the varicella-zoster virus (human herpesvirus type 3). It usually begins with mild constitutional symptoms that are followed... read more Chickenpox , rubella Rubella (See also Congenital Rubella.) Rubella is a contagious viral infection that may cause adenopathy, rash, and sometimes constitutional symptoms, which are usually mild and brief. Infection during... read more Rubella , and mumps Mumps Mumps is an acute, contagious, systemic viral disease, usually causing painful enlargement of the salivary glands, most commonly the parotids. Complications may include orchitis, meningoencephalitis... read more Mumps ). Localized viral conjunctivitis without systemic manifestations usually results from adenoviruses Adenovirus Infections Infection with one of the many adenoviruses may be asymptomatic or result in specific syndromes, including mild respiratory infections, keratoconjunctivitis, gastroenteritis, cystitis, and primary... read more (up to 90% of viral conjunctivitis) and sometimes enteroviruses Overview of Enterovirus Infections Enteroviruses, along with rhinoviruses (see Common Cold) and human parechoviruses, are a genus of picornaviruses (pico, or small, RNA viruses). All enteroviruses are antigenically heterogeneous... read more or herpes simplex virus Herpes Simplex Virus (HSV) Infections Herpes simplex viruses (human herpesviruses types 1 and 2) commonly cause recurrent infection affecting the skin, mouth, lips, eyes, and genitals. Common severe infections include encephalitis... read more Herpes Simplex Virus (HSV) Infections (1.3 to 4.8% of viral conjunctivitis).

Epidemic keratoconjunctivitis usually results from adenovirus serotypes Ad 5, 8, 11, 13, 19, and 37 and tends to cause severe conjunctivitis. Adenoviruses can also be identified by genotypes. Genotype HAdV-D is associated with conjunctivitis and HAdV-D53 and HAdV-D54 have been associated with epidemic keratoconjunctivitis. Pharyngoconjunctival fever usually results from serotypes Ad 3, 4, and 7. Outbreaks of acute hemorrhagic conjunctivitis, a rare conjunctivitis associated with infection by enterovirus type 70, have occurred in Africa and Asia. Ebola virus and SARS-CoV-2 infections (which are associated with the highly contagious and potentially fatal Ebola hemorrhagic fever Marburg and Ebola Virus Infections Marburg and Ebola are filoviruses that cause hemorrhage, multiple organ failure, and high mortality rates. Diagnosis is with enzyme-linked immunosorbent assay, polymerase chain reaction (PCR)... read more and COVID-19 COVID-19 Coronaviruses are enveloped RNA viruses that cause respiratory illnesses of varying severity from the common cold to fatal pneumonia. Numerous coronaviruses, first discovered in domestic poultry... read more , respectively) can manifest with bilateral conjunctival hyperemia, tearing, and systemic symptoms. Caution and appropriate personal protective equipment should be used when examining patients with conjunctivitis, systemic symptoms, and travel from high-risk regions.

Symptoms and Signs of Viral Conjunctivitis

After an incubation period of about 5 to 12 days, conjunctival hyperemia, watery discharge, and ocular irritation usually begin in one eye and spread rapidly to the other. Follicles may be present on the palpebral conjunctiva. A preauricular lymph node is often enlarged and painful. Many patients have had contact with someone with conjunctivitis, a recent upper respiratory infection, or both.

In severe adenoviral conjunctivitis, patients may have photophobia and foreign body sensation due to corneal involvement. Chemosis may be present. Pseudomembranes of fibrin and inflammatory cells on the tarsal conjunctiva, focal corneal inflammation, or both may blur vision. Even after conjunctivitis has resolved, residual corneal subepithelial opacities (multiple, coin-shaped, 0.5 to 1.0 mm in diameter) may be visible with a slit lamp for up to 2 years. Corneal opacities occasionally result in decreased vision and significant halos and starbursts.

Diagnosis of Viral Conjunctivitis

  • Clinical evaluation

Diagnosis of conjunctivitis and differentiation between bacterial Acute Bacterial Conjunctivitis Acute conjunctivitis can be caused by numerous bacteria. Symptoms are hyperemia, lacrimation, irritation, and discharge. Diagnosis is clinical. Treatment is with topical antibiotics, augmented... read more Acute Bacterial Conjunctivitis , viral Viral Conjunctivitis Viral conjunctivitis is a highly contagious acute conjunctival infection usually caused by an adenovirus. Symptoms include irritation, photophobia, and watery discharge. Diagnosis is clinical... read more Viral Conjunctivitis , and noninfectious conjunctivitis Allergic Conjunctivitis Allergic conjunctivitis is an acute, intermittent, or chronic conjunctival inflammation usually caused by airborne allergens. Symptoms include itching, lacrimation, discharge, and conjunctival... read more Allergic Conjunctivitis (see table Differentiating Features in Acute Conjunctivitis Differentiating Features in Acute Conjunctivitis Viral conjunctivitis is a highly contagious acute conjunctival infection usually caused by an adenovirus. Symptoms include irritation, photophobia, and watery discharge. Diagnosis is clinical... read more Differentiating Features in Acute Conjunctivitis ) are usually clinical; special tissue cultures are necessary for growth of the virus but are rarely indicated. Nucleic acid amplification tests (NAAT) and other rapid, office-based immunodiagnostic tests, can be useful especially when the inflammation is severe and other diagnoses (eg, orbital cellulitis Preseptal and Orbital Cellulitis Preseptal cellulitis (periorbital cellulitis) is infection of the eyelid and surrounding skin anterior to the orbital septum. Orbital cellulitis is infection of the orbital tissues posterior... read more Preseptal and Orbital Cellulitis ) must be ruled out. Features that may help differentiate between viral and bacterial conjunctivitis can include purulence of ocular discharge, presence of preauricular lymphadenopathy, and, in epidemic keratoconjunctivitis, chemosis. Patients with photophobia are stained with fluorescein and examined with a slit lamp. Epidemic keratoconjunctivitis may cause punctate corneal staining. Secondary bacterial infection of viral conjunctivitis is very rare. However, if any signs suggest bacterial conjunctivitis (eg, purulent discharge), cultures or other studies may be useful.

Table
icon

Treatment of Viral Conjunctivitis

  • Supportive measures

Viral conjunctivitis is highly contagious, and transmission precautions must be followed.

To avoid transmitting infection, physicians must

  • Use hand sanitizer or wash their hands properly (fully lather hands, scrub hands for at least 20 seconds, rinse well, and turn off the water using a paper towel)

  • Disinfect equipment after examining patients

Patients should do the following:

  • Use hand sanitizer and/or wash their hands thoroughly after touching their eyes or nasal secretions

  • Avoid touching the noninfected eye after touching the infected eye

  • Avoid sharing towels or pillows

  • Avoid swimming in pools

Eyes should be kept free of discharge and should not be patched. Small children with conjunctivitis should be kept home from school to avoid spreading the infection.

Viral conjunctivitis is self-limiting, lasting 1 week in mild cases to up to 3 weeks in severe cases. It requires only cool compresses for symptomatic relief. However, patients who have severe photophobia or whose vision is affected may benefit from topical corticosteroids (eg, 1% prednisolone acetate 4 times a day). Corticosteroids, if prescribed, are usually prescribed by an ophthalmologist. Herpes simplex keratitis Herpes Simplex Keratitis Herpes simplex keratitis is corneal infection with herpes simplex virus. It may involve the iris. Symptoms and signs include foreign body sensation, lacrimation, photophobia, and conjunctival... read more Herpes Simplex Keratitis must be ruled out first (by fluorescein staining and slit-lamp examination) because corticosteroids can exacerbate it. Topical cyclosporin A eye drops are overall less effective but are helpful if corticosteroid drop use is limited by adverse effects.

Key Points

  • Most viral conjunctivitis is a highly contagious infection caused by adenoviruses or enteroviruses.

  • Features that may help differentiate between viral and bacterial conjunctivitis can include purulence of ocular discharge, presence of preauricular lymphadenopathy, and, in epidemic keratoconjunctivitis, chemosis.

  • Diagnosis is usually clinical.

  • Treatment is usually cool compresses and measures to prevent spread.

Drugs Mentioned In This Article

Drug Name Select Trade
ORAPRED, PRELONE
Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Test your knowledge

Overview of Uveitis
Uveitis is defined as inflammation of the uveal tract and is classified anatomically as four different types. Of these types of uveitis, which of the following is localized to the vitreous cavity and/or pars plana?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
 

Also of Interest

 
TOP