Kawasaki Disease

Key Features

Essentials of Diagnosis

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

• Elevated erythrocyte sedimentation rate and C-reactive protein levels

• Risk for coronary arteritis and aneurysms

• Affects medium-sized arteries and multiple organs, causing

  • Elevations in serum transaminases

  • Interstitial pneumonitis

  • Abdominal pain

  • Vomiting and diarrhea

  • Gallbladder hydrops

  • Pancreatitis

  • Lymphadenopathy

  • Hypoalbuminemia

  • Arrhythmias

  • Aseptic meningitis

  • Acute encephalopathy with biphasic seizures and late reduced diffusion

  • Retinal and choroidal detachment

  • Pulmonary complications (effusions, empyema, pneumothorax)

  • Pyuria

General Considerations

• Also known as the "mucocutaneous lymph node syndrome"

• An acute, self-limiting, mucocutaneous vasculitis characterized by

  • Infiltration of vessel walls with mononuclear cells

  • IgA secreting plasma cells that can destroy the tunica media and cause aneurysm formation

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

• Occurs significantly more often in Asians or native Pacific Islanders

• Risk factors

  • Advanced maternal age

  • Mother of foreign birth

  • Maternal group B streptococcus colonization

  • Early infancy hospitalization for a bacterial illness

  • Genetic factors

• Cause remains unknown

Clinical Findings

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

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

  • Oral manifestations

    • Erythema and cracking of lips

    • Strawberry tongue

    • Erythema of oral and pharyngeal mucosa

  • Peripheral extremity changes

    • Erythema and edema of the hands and feet in the acute phase

    • Periungual desquamation within 2–3 weeks after the onset of fever

  • Polymorphous rash

  • Cervical lymphadenopathy

    • > 1.5 cm diameter

    • Usually unilateral

    • Least common of the clinical features

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

• A diagnosis of atypical or "incomplete" Kawasaki disease can be diagnosed in patients with unexplained fever and fewer than 4 criteria if accompanied by

  • Compatible laboratory findings or

  • Aneurysms detected by echocardiography or angiography

• A wide spectrum of rare diagnostic and recognized presentations include

  • Erythema multiforme rash

  • Onychomycosis

  • Cervical lymphadenopathy

  • Febrile seizures

  • Cheilitis

  • Torticollis

  • Facial nerve palsy

  • Beau lines of the nails

  • Inflammation at the site of BCG vaccination

  • Urinary tract infection

Differential Diagnosis

• Measles in unimmunized children

• Other viral infections, such as SARS-CoV-2, adenovirus, scarlet fever, hemophagocytic lymphohistiocytosis syndrome, and toxic shock syndrome

• Rickettsial infections or leptospirosis

• Drug hypersensitivity reactions

Diagnosis

• In the acute phase, following findings are typical:

  • Leukocytosis with neutrophilic predominance

  • Anemia

  • Elevated erythrocyte sedimentation rate (ESR)

  • Elevated C-reactive protein (CRP)

• High platelet counts are characteristic but occur in the second week

• N-terminal moiety of B-type natriuretic peptide (NT-proBNP)

  • May be elevated in some patients

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