eMedicine Specialties > Ophthalmology > Dermatologic Disorders

Kawasaki Disease

Kalpana K Jatla, MD, Private Practice, Clarity Eye Center
Robert William Enzenauer, MD, MPH, Professor, Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center
Contributor Information and Disclosures

Updated: Nov 14, 2008

Introduction

Background

Kawasaki disease (KD), also known as Kawasaki syndrome, was first described in Japan in 1967 by the pediatrician Tomisaku Kawasaki.¹

Since its original description, Kawasaki disease has been reported worldwide in children of all ethnic origins. Originally, Kawasaki disease was believed to be an acute, self-limiting febrile disease with an excellent prognosis; however, subsequent reports indicated that nearly 2% of patients with Kawasaki disease died from the illness, usually as a result of secondary cardiac sequelae.

See related CME at Highlights of the Pediatric Academic Societies and Asian Society for Pediatric Research Joint Meeting.

Pathophysiology

Kawasaki disease is a systemic vasculitis of unknown etiology that affects the small- and medium-sized blood vessels of the body, in particular, the coronary arteries.

Frequency

United States

The yearly incidence of endemic Kawasaki disease in the United States is 67 cases per 100,000 children who are younger than 5 years. Approximately 3,000 hospitalizations occur annually in the United States as a result of Kawasaki disease. Seasonal peaks occur in the spring and winter with a relative paucity of cases in the summer months.

International

The incidence in Europe is comparable to that of the United States. In Japan, where Kawasaki disease has the highest incidence, an estimated 5,000-6,000 cases occur annually.

Race

• The incidence of Kawasaki disease remains the highest in children of Japanese descent, although the disease has now been reported in children of all ethnic origins.
• In the United States, Kawasaki disease occurs most often in children of Asian ancestry, followed by African Americans. The lowest incidence is in whites.

Sex

The male-to-female ratio is approximately 1.5:1.

Age

• Of all Kawasaki disease cases, 80% occur in children younger than 4 years, with most cases in the United States presenting in children aged 1-2 years.
• In Japan, the highest incidence occurs in persons aged 6-12 months. Cases in children older than 14 years are rare.

Clinical

History

• The most characteristic clinical sign required to establish a diagnosis of Kawasaki disease is a fever that persists for 5 days or more. Fever is the initial sign of the illness in many patients, generally following a waxing and waning pattern and lasting for 11 days on average.
• In addition to fever, at least 4 of the following 5 criteria should be satisfied for diagnosis:
  • Changes of the peripheral extremities include initial reddening or edema of the palms and soles, followed by membranous desquamation of the finger and toe tips or transverse grooves across the fingernails and toenails (Beau lines)
  • A polymorphous, primarily truncal, exanthem
  • Oropharyngeal changes, including erythema, fissuring, and crusting of the lips, strawberry tongue, and diffuse mucosal injection of the oropharynx
  • Bilateral, nonexudative, painless bulbar conjunctival injection
  • Acute nonpurulent cervical lymphadenopathy with lymph node diameter greater than 1.5 cm
• Kawasaki disease is triphasic in nature with an acute, subacute, and convalescent phase.

Physical

• The acute phase lasts from 1-2 weeks and is characterized by a prolonged elevated temperature, often poorly responsive to antipyretics.
• The patient also manifests many or all of the criteria described in History.
  • More than 90% of children with Kawasaki disease develop an exanthem in the first few days of their illness, usually on the trunk and proximal extremities.
  • Lymphadenopathy is the least common sign, present in only 50-70% of patients.
• The subacute phase follows the acute phase, lasting 3-4 weeks. Many of the clinical symptoms begin to resolve, including the fever and rash.
• The final convalescent phase is marked by complete resolution of clinical signs of the illness, usually within 3 months of presentation.
• The most common ophthalmologic finding is bilateral conjunctival injection. Iridocyclitis, superficial punctate keratitis, vitreous opacities, papilledema, and subconjunctival hemorrhage also may occur.
  • Bilateral conjunctival erythema is one of the classical diagnostic criteria for Kawasaki disease, present in more than 90% of children with Kawasaki disease.
  • Mostly confined to the bulbar region
  • Nonexudative
  • Chemosis, follicles, and papillae are characteristically absent.
• A study by Blatt et al found that pediatricians seldom consider the eye redness significant enough to warrant ophthalmologic consultation.² The authors suggested that only hospitalized children who exhibited signs of fever, conjunctival injection, and oral lesions would benefit from ophthalmologic examination.
• Burns et al found evidence of uveitis in 83% of children who were diagnosed with Kawasaki disease in the first week of their illness.³
  • The anterior uveitis is usually mild and bilateral, sometimes associated with keratic precipitates.
  • The anterior uveitis peaks about a week after fever onset. It generally resolves within 2-8 weeks after disease onset without any of the common sequelae that often are seen with many other infectious causes of uveitis.
• Ohno et al found a significant incidence of superficial punctate keratitis (22%) in his study of patients with Kawasaki disease.⁴ Other findings noted in the study included papilledema (12%), vitreous opacities (12%), and subconjunctival hemorrhage (6%).⁴
• Ryan and Walton described a case of a 10-month-old male infant in whom bilateral scarring of the superior and inferior fornices developed in association with Kawasaki disease.⁵
• Less common posterior segment manifestations usually are limited to case reports. One such report by Font et al describes bilateral inner retinal ischemia due to thrombotic occlusion as a result of systemic vasculitis.⁶
• One case documents periorbital vasculitis in an 8-month-old infant with Kawasaki disease, a previously unreported manifestation of Kawasaki disease.

Causes

• The etiology remains unclear, although epidemiological data support an infectious cause. Thus far, the unknown agent generally is believed to be ubiquitous in the environment, causing noticeable disease only in those individuals with some as yet undiscovered genetic predisposition for the illness.
• Based upon epidemiologic data, person-to-person transmission of the disease is unlikely.
• Several organisms have been investigated as the possible etiologic agents, as follows: mite-associated bacteria, tick-borne diseases, Rickettsia species, Propionibacterium acnes, and several viruses, such as Epstein-Barr virus and retroviruses.
• Several investigators have noted the similarities of Kawasaki disease and toxic shock syndrome (TSS), a toxin-mediated disorder caused by a strain of Staphylococcus aureus and the streptococcal species.
  • The toxins elaborated by these strains are proposed to act as superantigens, molecules that elicit a more widespread immune response (eg, T-cell activation) in comparison to conventional antigens.
  • Some researchers believe that toxic shock syndrome and Kawasaki disease are different manifestations of the same disease.
• Other researchers believe that Kawasaki disease is caused by a unique bacterial toxin.
• Epidemiological studies suggest a controversial association of Kawasaki disease with recent carpet shampooing, flooding, and locations near bodies of water. These data have produced a water-borne vector hypothesis.

References

• Behcet Disease
• Conjunctivitis, Viral
• Inflammatory Bowel Disease
• Keratoconjunctivitis, Epidemic
• Pharyngoconjunctival Fever
• Rocky Mountain Spotted Fever
• Sarcoidosis
• Stevens-Johnson Syndrome
• Uveitis, Anterior, Childhood