AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
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Background

Epidemic keratoconjunctivitis (EKC) is a type of adenovirus ocular infection. This group of infections also includes pharyngoconjunctival fever and many other adenoviral strains that produce nonspecific follicular conjunctivitis. EKC is highly contagious and has the tendency to occur in epidemics. It has been reported worldwide.

One of the most common causes of acute viral conjunctivitis with unique clinical features is that it produces a sudden onset of acute follicular conjunctivitis with watery discharge, hyperemia, chemosis, and ipsilateral preauricular lymphadenopathy. Both membranes and pseudomembranes can occur in EKC with a distinguishing corneal involvement that ranges from diffuse, fine, superficial keratitis to epithelial defects to subepithelial opacities. Diagnosis is mainly clinical. Treatment is mostly symptomatic (cold compresses and artificial tears). In severe cases, mild topical corticosteroids can be used, especially for the subepithelial opacities.

Pathophysiology

More than 50 serotypes have been isolated, and at least 19 documented serotypes cause EKC. The most commonly associated serotypes include adenovirus 8, 19, and 37, and, less frequently, serotypes 2-5, 7, 9, 10, 11, 14, 16, 21, and 29. Because of low, natural immunity against adenovirus in the general population (eg, adenovirus type 8 antibodies are found in <5% of the general population in the United States), every individual is considered susceptible to infection.

EKC epidemics tend to occur in closed institutions (eg, schools, hospitals, camps, nursing homes, workplaces). Direct contact with eye secretions is the major mode of transmission. Other possible methods of transmission are through air droplets and possibly swimming pools. Adenovirus can be recovered from the eye and throat for as long as 14 days after the onset of clinical symptoms.

The infamous role of the medical profession in spreading the disease is well documented in the literature. Many epidemics have been initiated in ophthalmology outpatient clinics by direct contact with contaminated diagnostic instruments. The following explains the infectious transmission in hospitals and clinics: (1) the virus (adenovirus type 19) remains viable for 5 weeks, (2) the virus is resistant against standard disinfectants, such as 70% isopropyl alcohol and ammonia, and (3) the virus sheds from the eye 3 days before and 14 days after symptom onset.

EKC in East Asia and other parts of the world is endemic and does not appear to be transmitted through medical intervention. Viruses were isolated from more than 50% of cases of viral conjunctivitis; adenovirus constituted 94% of them.

Frequency

United States

The actual prevalence and incidence are unknown, because most cases are seen by general practitioners and optometrists. This infection does not have to be reported to any medical authority.

International

Same as in the United States.

Mortality/Morbidity

EKC is a self-limiting disease. It tends to resolve spontaneously within 1-3 weeks without significant complications.

• In 20-50% of cases, corneal opacities can persist for a few weeks to months (rarely up to 2 y). This phenomenon can significantly decrease visual acuity and cause glare symptoms.
• In rare cases, conjunctival scarring and symblepharon can occur secondary to membranous conjunctivitis.

Sex

No gender predilection exists.

Age

The infection is more common in adults, but all age groups can be affected.

CLINICAL

Section 3 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

History

This eye infection may be preceded by flulike symptoms, including fever, malaise, respiratory symptoms, nausea, vomiting, diarrhea, and myalgia.

• Often, a recent history of an eye examination or exposure within the family or at work is present.
• The incubation period is 2-14 days, and the person may remain infectious for 10-14 days after symptoms develop.
• The ocular symptoms are mainly sudden onset of irritation, soreness, red eye, photophobia, foreign body sensation, and excessive tearing.
• In more severe cases, patients can present with ocular and periorbital pain and decreased visual acuity.
• Symptoms tend to last for 7-21 days. The fellow eye tends to be involved in more than 50% of the cases within 7 days of onset. The signs and symptoms are typically less severe in the fellow eye.

Physical

• Ipsilateral preauricular lymphadenopathy is one of the classic findings.
• Decreased visual acuity is rarely present; it is usually present only if there is corneal involvement.
• Other clinical signs include the following:
• • Swelling and erythema of the lid
  • Conjunctival hyperemia
  • Chemosis
  • Follicular reaction, mainly in the lower palpebral conjunctiva (the earliest and most common sign)
  • Papillary hypertrophy
  • Subconjunctival and petechial hemorrhage
• In severe cases, membranous and pseudomembranous conjunctivitis can be seen in one third of cases, which can lead to conjunctival scarring and symblepharon.
• One of the distinguishing features of EKC is corneal involvement, which is usually mild and transient.
• • Corneal involvement has been well documented 3-4 days after symptom onset in the form of diffuse fine epithelial keratitis that stains with both fluorescein and rose bengal. This keratitis can persist for 2-3 weeks. In rare cases, a frank corneal epithelial defect may occur.
  • One week after the onset, focal epithelial keratitis may develop. This is characterized by central ulceration and irregular borders with gray-white dots. These epithelial changes are related to active viral infection. These lesions persist for 1-2 weeks.
  • About 2 weeks after onset, subepithelial infiltrates can appear beneath the focal epithelial lesions, persisting for weeks to years. They resolve spontaneously, usually without scarring. These infiltrates are immunological in nature.
  • In rare cases, disciform keratitis or anterior uveitis can occur.
  • There is no change in corneal sensation.

Causes

EKC is a type of adenovirus ocular infection. See Pathophysiology.

DIFFERENTIALS

Section 4 of 11  

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• Differentials
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Other Problems to be Considered

Differential diagnosis of acute follicular conjunctivitis includes the following:

Epidemic keratoconjunctivitis
Pharyngoconjunctival fever
Acute trachoma
Acute inclusion conjunctivitis
Primary herpes simplex conjunctivitis
Acute hemorrhagic conjunctivitis
Infectious mononucleosis
Neonatal inclusion conjunctivitis

Differential diagnosis of subepithelial corneal opacities includes the following:

Epidemic keratoconjunctivitis
Herpes simplex infection
Herpes zoster infection
Infectious mononucleosis
Epstein-Barr virus infection
Dimmer keratitis
Brucellosis

WORKUP

Section 5 of 11  

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• Clinical
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• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Lab Studies

• A diagnosis is routinely based on the characteristic clinical features.
• A simple way to diagnose EKC is by conjunctival cytology with Giemsa stain to look for intranuclear inclusions and lymphocytes.
• To confirm the diagnosis, viral culture is the criterion standard. Use a human epithelial cell line and a Chlamydia transport media.
• Other available diagnostic methods include fluorescent antibody techniques, Adenoclone or enzyme immune assay, complement fixation, and polymerase chain reaction (PCR).

TREATMENT

Section 6 of 11  

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• Clinical
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• Medication
• Follow-up
• Miscellaneous
• Multimedia
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Medical Care

Supportive management includes the following:

• Artificial tears
• Cold compresses
• Cycloplegic agents for severe photophobia
• Topical corticosteroids
• • Use for severe membranous conjunctivitis or marked reduction in visual acuity from late subepithelial opacities.
  • Taper slowly over a period of weeks to months to avoid recurrence of the corneal opacities.
• Research has been ongoing for topical agents that have antiviral activity. Cidofovir has been shown to reduce the viral replication cycle and also to be effective as a prophylactic agent. Cidofovir may prove to be one of the most useful topical antiviral agents in the treatment and prophylaxis of EKC epidemics that constitute a professional hazard for all eye care professionals.¹

Surgical Care

• Surgery is extremely rare and reserved for severe cases with cicatricial conjunctivitis secondary to symblepharon.
• If surgery is necessary, it is mainly in the form of fornix reconstruction and entropion repair.

MEDICATION

Section 7 of 11  

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The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Drug Category: Corticosteroids

Topical corticosteroids are a group of anti-inflammatory agents that cause inhibition of inflammatory response by potentiation of epinephrine vasoconstriction, stabilization of lysosomal membranes, decrease macrophage movement, prevention of kinin release, interfere with lymphocytes and neutrophil function, and inhibition of prostaglandin synthesis through inhibition of phospholipase enzyme.

FOLLOW-UP

Section 8 of 11  

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• Differentials
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• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Further Outpatient Care

• Depending on the severity of the signs and symptoms, patients should be followed up in several days to weeks.
• Any patient on topical corticosteroids should be observed routinely to monitor for adverse effects, including elevated intraocular pressure and cataract formation.

Deterrence/Prevention

• Patients should be very careful not to spread the infection by not touching others, by not sharing tissues, towels, or handkerchiefs, and by washing their hands frequently as long as the eye is red.
• Eye care professionals need to be extremely cautious regarding spreading of this infection to themselves or other patients. They should wash their hands immediately after examining any patient with a red eye. Anything the patient might have touched (especially the examination chair, slit lamp, and occluder) should be disinfected by office personnel immediately after the patient leaves the room.

Complications

• Severe decrease in visual acuity secondary to subepithelial corneal opacities
• Conjunctival scarring and symblepharon

Prognosis

• EKC is self-limiting and resolves spontaneously within 2-3 weeks.

Patient Education

• Prevention is the most important aspect of management.
• • Wash your hands before examining any patient.
  • Properly clean and sterilize ophthalmic instruments with hypochlorite solution.
  • Create a "red eye room" to separate red eye patients from others in the waiting room.
  • Patients who are infected should not share towels, pillows, washcloths, or other communal objects.
  • Personnel who are infected should be removed from duty for 2 weeks.
  • Warn other family members about the disease.
• For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education articles Pinkeye and How to Instill Your Eyedrops.

MISCELLANEOUS

Section 9 of 11  

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• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• Every effort needs to be made not to spread infections from one patient to another patient. A “red eye room” is a very good idea to try and limit potential spread. After any patient with a possible EKC infection is seen, the room needs to be disinfected. Physicians should wash their hands thoroughly after seeing any patient with a red eye. As a routine, they should wash their hands before seeing all patients.

MULTIMEDIA

Section 10 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Media file 1:  Follicular conjunctivitis and subconjunctival hemorrhage.
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Media type:  Photo

Media file 2:  Symblepharon secondary to epidemic keratoconjunctivitis.
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Media type:  Photo

REFERENCES

Section 11 of 11

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• Miscellaneous
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• References

1. Romanowski EG, Yates KA, Gordon YJ. Antiviral prophylaxis with twice daily topical cidofovir protects against challenge in the adenovirus type 5/New Zealand rabbit ocular model. Antiviral Res. Dec 2001;52(3):275-80. [Medline].
2. Hillenkamp J, Reinhard T, Ross RS, Bohringer D, Cartsburg O, Roggendorf M, et al. The effects of cidofovir 1% with and without cyclosporin a 1% as a topical treatment of acute adenoviral keratoconjunctivitis: a controlled clinical pilot study. Ophthalmology. May 2002;109(5):845-50. [Medline].
3. Kaufman HE, Barron BA, McDonald MB. Nonherpetic viral infections. Cornea. 1998;303-6.
4. Krashmer JH, Mannis MJ, Holland E. Conjunctivitis: an overview and classification, viral conjunctivitis. Cornea. 2005;601-612, 629-634.
5. Leibowitz HM, Waring GO. Superficial punctate keratopathy. In: Clinical Disorders: Clinical Diagnosis and Management. 1998:445-7.
6. Romanowski EG, Gordon YJ, Araullo-Cruz T, Yates KA, Kinchington PR. The antiviral resistance and replication of cidofovir-resistant adenovirus variants in the New Zealand White rabbit ocular model. Invest Ophthalmol Vis Sci. Jul 2001;42(8):1812-5. [Medline].
7. Sambursky R, Tauber S, Schirra F, Kozich K, Davidson R, Cohen EJ. The RPS adeno detector for diagnosing adenoviral conjunctivitis. Ophthalmology. Oct 2006;113(10):1758-64. [Medline].
8. Smolin G, Thoft RA. Viral keratitis and conjunctivitis. In: Cornea: Scientific Foundations and Clinical Practice. 2005:359-364.
9. Sutphin JE, et al. Viral infections. In: Section 8. AAO Basic and Clinical Science Course. 2006:157-160.
10. Duane's Clinical Ophthalmology on CD-ROM [book on CD-ROM]. 2006. Tasman W, Jaeger EA.
11. Yanoff M, Duker JS. Disorders of the conjunctiva and limbus. Ophthalmology. 2004;chapter 55:399-401.

Article Last Updated: Jan 7, 2008