I. Definitions and pathophysiology

  1. aka "Mucocutaneous lymph node syndrome"
  2. A multisystem vasculitis; etiology is unknown
  3. Generally limited to children

II. Clinical features and epidemiology

  1. Epidemiology
    1. 50% occurs before 2.5 y; 35% 2.5-5y, rare >10y
    2. Most common in kids of Asian or African descent
    3. Male > Female
    4. Fatal in 0.5% of cases, more likely to be fatal in boys and pts < 3yo
  2. Present includes fever, usually > 5d
  3. Natural history
    1. Self-limited
    2. Generally three stages
      1. Acute (7-14d, ending with resolution of fever)
      2. Subacute (arthralgias, desquamation of hands/feet, thrombocytosis, usually through about day 25)
      3. Convalescent (gradual resolution of clinical signs and laboratory abnormalities)
  4. Diagnostic criteria--Need fever x > 5d and four of the following, without evidence of another cause for the illness. If coronary aneurysms are documented, only 3 of the following are required for diagnosis:
    1. Conjunctival injection (bilateral, nonexudative, spares limbus)
    2. Oropharyngeal lesions (red or cracked lips, strawberry tongue, or injected mucosae)
    3. Erythematous, polymorphous rash (often "blotchy"; target-like or purpuric in 20% of cases)
    4. Erythema of palms and soles and/or edema of the hands or feet followed by periungual desquamation
    5. Cervical adenopathy in the anterior cervical triangle with at least one node larger than 1.5 cm in diameter (usually unilateral; 50-75% of pts)
  5. Other clinical features:
    1. Cardiac (leading cause of morbidity and mortality)
      1. Can cause coronary vasculitis and aneurysms with fatal complications i.e. acute MI (coronary artery abnormalities tend to occur after initial symptoms subside; occur in about 25% of cases but resolve within 18mos in 50% of patients)
      2. ECG usually shows tachycardia; may have mildly prolonged PR interval, TWI or flattening, and nonspecific ST changes.
      3. Other cardiac abnormalities reported: aortic regurgitation, mitral regurgitation, conduction system dysfunction, myocardial dysfunction with heart failure, pericardial effusion, and myocardial fibrosis
      4. Cardiac complications are more common in children < 1yo and in patients in who fever resolves for 24h or more and then recurs
    2. Musculoskeletal: Can have acute arthritis
    3. Gastrointestinal: Can have diarrhea, vomiting, hepatic dysfunction, gallbladder hydrops
    4. CNS: Can have irritability, aseptic meningitis, sensoryneural hearing loss
    5. GU: Can have urethritis
  6. Laboratory features
    1. CBC usually shows high WBC w/left shift, high platelet counts; sometimes mild anemia
    2. ESR and CRP usually elevated
    3. Sometimes low serum albumin
    4. Can have sterile pyuria and albuminuria
  7. Differential diagnosis
    1. Toxic shock syndrome
    2. Scarlet fever
    3. Stevens-Johnson syndrome
    4. Juvenile idiopathic arthritis with systemic onset
    5. Measles
    6. Adenovirus infection
    7. Echovirus infection
    8. Adverse drug reactions

III. Treatment

  1. Aspirin (generally given at high doses until fever resolves then at reduced dose for 6-8wks)
  2. Intravenous Immune Globulin (IVIG)-Helps reduce symptoms & risk of coronary aneurysms; Can cause fever, chills, hypotension, and rarely, hemolytic anemia
  3. Corticosteroids-Reduces length of illness; unclear whether reduces risk of cardiac complications, and in fact may increase incidence in some studies (not cited below)
    1. 39 pts with Kawasaki's randomized to methylprednisolone 30mg/kg IV; all pts also received ASA and were randomized to receive IVIG. Compared with the ASA-IVIG-alone group, the ASA-IVIG-steroid group had sig. shorter mean duration of fever (1.0 vs. 2.4d) and mean duration of hospital stay (1.9 vs. 3.3d) (J. Peds. 142:611, 2003--abst)
    2. In a meta-analysis of 8 randomized studies of corticosteroids vs. placebo in pts with Kawasaki's disease, incidence of coronary artery aneurysms was sig. lower in corticosteroid recipients (OR 0.55); only 3 of these studies included IVIG as part of standard therapy, though steroids were found to be beneficial in an analysis of just those three studies as well (Peds. 116:989, 2005--JW)
    3. In a study in 178 pts with Kawasaki disease, all of whom were treated with IVIG, randomized to prednisolone 2mg/kg/d vs. placebo until temperature and CRP were normal, there was no sig. diff. in prevalence of coronary artery abnormalities at 1mo, though prednisolone group had sig. faster resolution of fever and high CRP (J. Peds. 149:336, 2006--JW)
    4. In a study in in 199 children with Kawasaki disease and fever for 10d randomized to methylprednisolone 30mg/kg IV x 1 vs. placebo (all received IVIG + ASA), there were no sig. diffs. at 1wk or 5wks in various measures of coronary disease though IV steroid recipients had shorter initial hospitalization stays (NEJM 356:659, 2007--JW)
  4. Antipyresis
  5. Follow-up echocardiography recommended by AHA (as of 2004) 6-8wks after initial presentation and again 6-12mos later; however, the latter was not likely to show abnormalities in pts whose first f/u echo was normal in one retrospective study (Am. J. Cardiol. 88:328, 2001--AFP)

(Sources include West. J. Med. 168:23, 1998--AFP; Core Content Review of Family Medicine, 2012)