An acute febrile multi-system vasculitis of unknown etiology; Kawasaki disease can cause serious morbidity and potential mortality from cardiovascular complications: coronary artery aneurysms, myocarditis, arrhythmias, sudden death.
Epidemiology
– Most commonly affects Japanese, Male>Female, Occurs year-round with epidemic clusters in winter and spring, seen exclusively in children, adult KD often misdiagnosed, actually toxic shock syndrome.
Clinical Manifestations
(1) Fever of >5 days associated with at least 4 of 5 clinical findings:
(2) Bilateral non-purulent conjunctivitis
(3) One or more mucous membrane changes: pharyngeal injection, injected cracked lips, strawberry tongue.
(4) One or more extremity changes: peripheral erythema and edema with periungual desquamation.
(5) Rash, primarily truncal, sometimes perineal.
(6) Cervical lymphadenopathy >1.5 cm each with induration and tenderness.
Associated Criteria
:
Gastrointestinal-Diarrhea, hyperbilirubinemia, hydrops of gallbladder (gallbladder is pushed down and get RUQ tenderness)
Genitourinary – Sterile pyuria.
Complications
: Primarily cardiovascular, seen in 20% of patients with Kawasaki disease;
Coronary artery aneurysms
(also axillary, brachial, iliac, renal and femoral); risk of aneurysms correlates best with thrombocytosis—platelet count a marker of disease severity. Axillary aneurysms prognosticate poorly; high risk for coronary artery aneurysm formation.
major 3 complications (MI, arrhythmias and sudden death) can occur as long as 5 years after onset of illness!
Poor Prognosticators
: (predictive of coronary artery aneurysmal formation): Male, Age < 12 months, Duration of fever (>2 weeks), Degree of thrombocytosis, Palpable axillary aneurysm.
Etiology
: Unknown, but presumed infectious (due to its febrile, exanthematous and self-limited nature) or immunologic (due to elevation of cytokines, interleukin-1 and tumor necrosis factor).
Pathology
: vasculitis of medium and large arteries, aneurysms, gross cardiac hypertrophy.
Differential Diagnosis
: Kawasaki disease is a clinical diagnosis; differential diagnosis includes any disease causing fever and rash: roseola (human herpes virus 6), meningococcemia, measles (rubeola), acrodynia (mercury poisoning), scarlet fever, leptospirosis, enteroviral infection, Rocky Mountain Spotted Fever.
Treatment
: intravenous gamma globulin (IVIG), decreases risk of coronary aneurysms to 4% if given within 10 days, high dose aspirin acutely Þ low dose chronically.
Prognosis
: KD primarily an acute, self-limited disease; however, cardiac insults may be permanent and progressive, manifesting soon after onset (as early as 7 days) or not until years later. Infants (<12 months) have an especially poor prognosis since their presentation is often atypical and their therapy therefore delayed. ~ 2/3 of patients found to have coronary artery aneurysms will show regression of their aneurysms, however, stenosis, tortuosity and thrombosis of coronary vessels may still occur. Long-term prognosis for patients having had KD are still not understood. Recurrences of KD are uncommon (3%) and can occur as long as 8 years after the initial attack.