From the Guidelines
Kawasaki disease is diagnosed based on clinical criteria, requiring fever lasting at least 5 days plus at least 4 of 5 principal clinical features: bilateral conjunctival injection without exudate, changes in oral mucosa, polymorphous rash, changes in extremities, and cervical lymphadenopathy greater than 1.5 cm in diameter, as outlined in the American Heart Association's scientific statement 1. The diagnosis of Kawasaki disease is based on the presence of fever for at least 5 days and at least 4 of the 5 principal clinical features, which include:
- Erythema and cracking of lips, strawberry tongue, and/or erythema of oral and pharyngeal mucosa
- Bilateral bulbar conjunctival injection without exudate
- Rash: maculopapular, diffuse erythroderma, or erythema multiforme-like
- Erythema and edema of the hands and feet in acute phase and/or periungual desquamation in subacute phase
- Cervical lymphadenopathy (≥1.5 cm diameter), usually unilateral, as stated in the Circulation journal article 1. In some cases, the diagnosis may be made with only 4 days of fever, particularly when redness and swelling of the hands and feet are present, or with only 3 days of fever in rare instances with a classic clinical presentation, as noted in the American Heart Association's scientific statement 1. Laboratory findings that support the diagnosis include elevated inflammatory markers (ESR, CRP), leukocytosis, anemia, thrombocytosis (typically after 7 days), hypoalbuminemia, elevated liver enzymes, and sterile pyuria, which are commonly observed in patients with Kawasaki disease 1. Echocardiography should be performed to assess for coronary artery abnormalities, which are the major complication of Kawasaki disease, and early diagnosis is crucial as treatment with intravenous immunoglobulin (IVIG) 2 g/kg as a single infusion within 10 days of fever onset significantly reduces the risk of coronary artery aneurysms, as recommended in the Circulation journal article 1.
From the Research
Diagnostic Criteria for Kawasaki Disease
The diagnostic criteria for Kawasaki disease, also known as Mucocutaneous Lymph Node Syndrome, are based on clinical findings. According to 2, 3, 4, the classic (typical) diagnosis is made when a patient has a fever lasting five or more days, accompanied by four out of five of the following findings:
- Bilateral conjunctival injection
- Oral changes such as cracked and erythematous lips and strawberry tongue
- Cervical lymphadenopathy
- Extremity changes such as erythema or palm and sole desquamation
- Polymorphous rash
Incomplete (Atypical) Kawasaki Disease
Incomplete (atypical) Kawasaki disease occurs in persons with fever lasting five or more days and with two or three of the above findings, as stated in 2.
Laboratory and Imaging Tests
While there are no specific laboratory tests that definitively identify Kawasaki disease, supplementary laboratory criteria can aid in the diagnosis, particularly in cases of incomplete clinical presentation, as mentioned in 3. Transthoracic echocardiography is the diagnostic imaging modality of choice to screen for coronary aneurysms, as noted in 2. Other imaging techniques, such as computed tomography (CT) coronary angiography, may also be used, as seen in 5.
Challenges in Diagnosis
Diagnosis of Kawasaki disease can be challenging, especially in adults, as the clinical presentation can be mistaken for other illnesses, and symptoms may present sequentially over time rather than simultaneously, as discussed in 5.