Mucocutaneous lymph node syndrome (MCLS), also known as Kawasaki disease, was first reported by Kawasaki in 1967 as a febrile exanthematous disease of unknown cause, characterized by high fever, distinctive skin and mucosal lesions, and cervical lymphadenopathy. It has now been reported worldwide, including in Beijing, Shanghai, Sichuan, and other regions of China. The prognosis is generally good, but a few cases may result in sudden death due to coronary arteritis accompanied by coronary aneurysm rupture or thrombotic occlusion.

bubble_chart Auxiliary Examination

1. Blood: Changes include leukocytosis with a left shift, grade I anemia. Platelets are often elevated, even reaching 1.2×10¹²/L. ESR is increased. CRP is positive, while ASO titers are not elevated. α2-globulin levels rise. Some children show increased ALT and AST activity.
2. Urine: Proteinuria and increased white blood cells in the urinary sediment.
3. Stool: Often loose, with no red or white blood cells on microscopy, and negative bacterial culture.
4. Liver function: Some children may have elevated transaminases.
5. Cerebrospinal fluid: A few may show increased intracranial pressure, grade I lymphocytosis, with normal protein and glucose levels.
6. Chest X-ray: May be normal or abnormal. Cardiac silhouette may be enlarged.
7. Electrocardiogram: Left ventricular overload, prolonged P-R and Q-T intervals, ST-segment and T-wave changes, low voltage tendency, and arrhythmias.
8. Echocardiography: May reveal pericardial effusion, coronary artery dilation, or coronary artery aneurysms.
9. Electroencephalogram: A few may show abnormalities.

bubble_chart Diagnosis

1. Generally, this disease is most common in children aged 2 months to 8 years, with more than half of cases occurring in those under 2 years old, and over 80% in those under 4 years old. Males are slightly more affected than females. It can occur year-round but is most prevalent from March to September.
2. Main symptoms: The disease can be diagnosed when four or more of the following symptoms are present.
   1. Fever lasting at least one week, sometimes up to 2–3 weeks, with high fever exceeding 40°C. The child may experience dysphoria or drowsiness.
   2. Bilateral conjunctival congestion appears 3–4 days after the fever starts and subsides when the fever resolves.
   3. Oral manifestations include dry, red lips with rhagades, enlarged tongue papillae resembling a strawberry tongue, congested oral and pharyngeal mucosa, and swollen tonsils, sometimes with exudate.
   4. Extremity changes: Early in the illness, hands and feet show widespread firm swelling with reddened palms and metatarsal areas, and spindle-shaped swelling of fingers and toes. During the stage of convalescence, desquamation occurs at the fingertips and toe tips, appearing as thin flakes or membranous peeling.
   5. The rash is polymorphous erythema, mainly on the trunk, without blistering or crust formation.
   6. Cervical lymphadenopathy with nodes measuring 1.5–4.5 cm in diameter, firm and tender but not red or swollen, resolving when the fever subsides.
3. Minor symptoms
   1. Cardiovascular involvement may include carditis, myocarditis, or coronary artery damage. Heart murmurs, muffled heart sounds, or gallop rhythm may be heard.
   2. Diarrhea, vomiting, and abdominal pain.
   3. Proteinuria and increased white blood cells in urine sediment.
4. Rare symptoms
   1. Joint symptoms: Small joints like fingers and toes may show spindle-shaped swelling, while large joints such as knees, ankles, or wrists may exhibit fever, swelling, pain, and limited mobility.
   2. Aseptic meningitis with bulging anterior fontanelle and increased intracranial pressure.
   3. Liver involvement: A few cases may present with hepatitis or grade I jaundice.

bubble_chart Treatment Measures

1. Supportive therapy involves providing adequate nutrition and fluids. For severe cases, small and frequent transfusions of plasma may be administered. Attention should be paid to correcting typical edema, electrolyte imbalances, and acid-base disturbances. For patients with myocardial damage, adenosine triphosphate (ATP) and coenzyme A can be given.
2. Anticoagulation therapy is used to prevent coronary artery embolism, with aspirin administered at 30 mg/(kg·d), divided into three oral doses, and reduced after fever subsides. The treatment course should last at least 2 months. Other options include heparin or dicoumarol for anticoagulation. Vitamin E (20–30 mg/(kg·d)) and dipyridamole (3–5 mg/(kg·d)) may also be added.
3. Anti-infection therapy may involve cephalosporins or other antibiotics until the fever subsides. However, its effectiveness remains to be further observed.
4. To suppress hypersensitivity reactions, corticosteroids can be used to improve fever, mucosal symptoms, and erythrocyte sedimentation rate (ESR). However, some observations suggest that corticosteroids may exacerbate coronary arteritis and contribute to coronary artery occlusion, so their use should be avoided.
5. Early administration of gamma globulin can reduce the incidence of coronary artery aneurysms. The dose is 400 mg/(kg·d), infused over 2–4 hours for 4 consecutive days, or 1 g/(kg·d) for 2 consecutive days. This may be used for high-risk patients (e.g., those with onset age <1歲，CRP強陽性，血小板< 20×10⁹ /L, plasma protein <5g/L及紅細胞壓積<35%的患兒)。
6. During the convalescence stage, patients should undergo regular follow-ups, with particular attention to those with cardiovascular changes.

bubble_chart Differentiation

It should be differentiated from scarlet fever, Bi disease, myocarditis, and exudative polymorphous erythema.