Merck Manual

Please confirm that you are a health care professional

honeypot link

Viral Conjunctivitis

By

Zeba A. Syed

, MD, Wills Eye Hospital

Reviewed/Revised Apr 2023
View 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 (eg, fever... read more Chickenpox , rubella Rubella (See also Congenital Rubella.) Rubella is a viral infection that may cause adenopathy, rash, and sometimes constitutional symptoms, which are usually mild and brief. Infection during early pregnancy... 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 is a severe form of viral conjunctivitis that is usually caused by adenovirus serotypes Ad 5, 8, 11, 13, 19, and 37. 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 COVID-19 is a respiratory illness caused by the novel coronavirus SARS-CoV-2. Infection may be asymptomatic or have symptoms ranging from mild upper respiratory symptoms to acute respiratory... 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 epidemic keratoconjunctivitis, 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 Slit-lamp examination The eye can be examined with routine equipment, including a standard ophthalmoscope; thorough examination requires special equipment and evaluation by an ophthalmologist. History includes location... read more for up to 2 years. Corneal opacities occasionally result in decreased vision and significant halos and starbursts.

Diagnosis of Viral Conjunctivitis

  • Clinical evaluation

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

Treatment of Viral Conjunctivitis

  • Supportive measures

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

Physicians take the following precautions to avoid transmitting infection:

  • 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 Slit-lamp examination The eye can be examined with routine equipment, including a standard ophthalmoscope; thorough examination requires special equipment and evaluation by an ophthalmologist. History includes location... read more ) 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. In severe cases, any conjunctival pseudomembranes should be removed at the slit-lamp examination to reduce the chances of conjunctival scarring and symblepharon formation.

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
AK-Fluor, Bio Glo, Fluorescite, Fluorets , Fluor-I-Strip, Fluor-I-Strip A.T., Ful-Glo, Ophthalmicflur
AK-Pred, AsmalPred, Econopred, Econopred Plus, Flo-Pred, Hydeltrasol, Inflamase Forte, Inflamase Mild, Millipred , Millipred DP, Millipred DP 12-Day, Millipred DP 6 Day, Ocu-Pred , Ocu-Pred A, Ocu-Pred Forte, Omnipred, Orapred, Orapred ODT, Pediapred, Pred Mild, Predalone, Pred-Forte, Prednoral, Pred-Phosphate , Prelone, Veripred-20
View PATIENT EDUCATION
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz! 
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP