Kawasaki Disease

Key Features

Essentials of Diagnosis

• Fever, conjunctivitis, oral mucosal changes, rash, cervical lymphadenopathy, peripheral extremity changes

• Elevated ESR and CRP levels

• Risk for coronary arteritis and aneurysms

General Considerations

• An acute, self-limiting, mucocutaneous vasculitis

• Characterized by the infiltration of vessel walls with mononuclear cells and later by IgA secreting plasma cells that can result in the destruction of the tunica media and aneurysm formation

• Cause remains unknown

• Occurs mainly in children between the ages of 3 months and 5 years but can occur occasionally in adults as well

• Multisystem inflammatory syndrome in children (MIS-C)

  • Appears to affect older children (median age 9–11 years) than Kawasaki disease

  • Seems to be more severe than Kawasaki disease

  • Reports of this syndrome came during the peak time of the SARS-CoV-2 pandemic in Bergano (mid-February 2020 to mid-April 2020)

  • Since these initial reports, there have been multiple reports of similar disease from the United States and other European countries

  • This new syndrome raises the question of whether MIS-C is an immune response to SARS-CoV-2

Demographics

• Kawasaki disease occurs most often in Asians or native Pacific Islanders

• Its incidence in Japan is twice that of the United States, and it occurs among siblings at twice the incidence of cases and at higher rates among parents of cases

Clinical Findings

Symptoms and Signs

• A clinical diagnosis of classic or "complete" Kawasaki disease requires the presence of at least 5 days of fever, usually high-grade (over 39°C to 40°C) and four of the following five criteria:

  • Bilateral nonexudative conjunctivitis (begins shortly after the onset of fever)

  • Oral changes of erythema and cracking of lips, strawberry tongue, and erythema of oral and pharyngeal mucosa; (ulcers and pharyngeal exudates are not consistent with Kawasaki disease)

  • Peripheral extremity changes (erythema and edema of the hands and feet in the acute phase, and/or periungual desquamation within 2–3 weeks after the onset of fever)

  • Polymorphous rash

  • Cervical lymphadenopathy (>1.5 cm, usually unilateral; least common of the clinical features)

• The revised case definition allows the diagnosis on day 4 in the presence of more than four principal clinical criteria, particularly when redness and swelling of the hands and feet are present

• A diagnosis of atypical or "incomplete" Kawasaki disease could be diagnosed in patients with unexplained fever and fewer than four principal criteria if accompanied by compatible laboratory or findings of aneurysms detected by echocardiography or angiography

• The CDC's case definition of MIS-C includes patients younger than 21 years who have had

  • Fever (higher than 38.0°C for at least 24 hours, or report of subjective fever lasting at least 24 hours)

  • Laboratory evidence of inflammation

  • Evidence of clinically severe illness that requires hospitalization, with multisystem (more than two) organ involvement ...