Cutaneous mucocutaneous lymph node syndrome, also known as Kawasaki disease, is a disease with a pathological basis in systemic vasculitis that is unique to childhood. It can develop at all ages, most of them within 5 years of age, more boys than girls, and the male to female ratio is 1.3-1.5:1.
Etiology and pathogenesis
The cause of the disease is not clear, and may be related to infection, immune dysfunction and genetics. It is believed that the disease is an immune-mediated systemic vasculitis triggered by a variety of infectious agents in a susceptible host.
Diagnosis
(A) Clinical stages and signs and symptoms
1. Acute stage: 1-10 days after onset. The pathology is small arteries, small veins and capillaries inflammation, perivascular inflammation, large and medium artery endotheliitis.
(1) Symptoms: mostly rapid onset, persistent fever, ineffective antibiotic treatment, may be accompanied by cough, runny nose or diarrhea; red lips and mouth, red bulbar conjunctiva, skin rash, neck mass, red and swollen hands and feet, joint pain, etc. Some patients may have headache, vomiting and other symptoms.
(2) Signs: hyperthermia, polymorphic erythema on the skin, mostly on the trunk, skin congestion at the BCG vaccination site and around the umbilicus and anus, conjunctival congestion of both eyes, flushed and chapped lips, positive prune tongue, enlarged cervical lymph nodes, hard swollen and congested hands and feet, joints may have redness, swelling, pressure pain and impaired movement; positive meningeal irritation sign when aseptic meningitis is present.
2. Subacute stage: the duration of the disease is 11-28 days. Pathologically small vasculitis is reduced, with moderate arteritis predominating, mostly coronary artery aneurysms, thrombosis and luminal stenosis.
(1) Symptoms: fever decreases, rash subsides, neck mass decreases, redness of mouth and lips and bulbar conjunctiva decreases, peeling of skin at the ends of fingers and toes of hands and feet, shortness of breath, pallor, panic and shortness of breath and weakness may be present in cases of complicated heart failure.
(2) Signs: hypothermia or normal body temperature, receding rash, reduced cervical lymph nodes, reduced congestion of the bulbar conjunctiva and lips, membrane peeling at the ends of the fingers and toes, accelerated heart rate, arrhythmia, low heart sounds, etc. in cases of heart damage.
3. Recovery period: the course of the disease is 29-45 days. The pathological manifestations are small vessels and capillaritis subsiding, medium arterial granulation tissue proliferation, intimal thickening.
(1) Symptoms: symptoms basically disappear, and those with residual cardiovascular lesions may have corresponding symptoms, such as weakness and pallor.
(2) signs: no obvious positive signs, combined with heart damage may have accelerated heart rate, arrhythmia, heart murmur, etc.
4. Chronic phase: The course of the disease is 46 days to several years. The acute inflammation of blood vessels basically disappears, moderate arterial thrombosis, intimal thickening, aneurysm and scar formation appear.
There are no obvious symptoms and signs in this period, or there are cardiovascular disease manifestations.
(B) Laboratory tests
1. The total white blood cell count and neutrophil classification are significantly increased in the acute stage, hemoglobin is mildly decreased, platelets may be normal, and platelets may be significantly increased in 2-3 weeks of the disease.
2. Increased blood sedimentation.
C-reactive protein is increased.
4. Protein electrophoresis shows an increase in globulin and a decrease in albumin.
5. The total leukocyte count in the cerebrospinal fluid is mildly to moderately elevated in those with aseptic meningitis, and the classification is mainly lymphatic.
6. If liver function is impaired, transaminases may be mildly to moderately increased.
7. X-ray chest film may show small non-particular patchy shadow.
8. Echocardiography or coronary angiography may show coronary artery dilatation or coronary artery aneurysm formation, and may also show pericarditis, valve closure insufficiency, and heart enlargement. The electrocardiogram may show S-T segment hypoplasia, flat or inverted T waves, conduction block, etc.
(iii) Diagnostic criteria
Diagnostic criteria revised by the Japanese Kawasaki Disease Committee in 1984.
1．Fever for 5 days or longer, antibiotic treatment is ineffective.
2. Bilateral bulbar conjunctival congestion.
3. Oral and lip changes: congestion and chapping of the mouth and lips, diffuse congestion of the oral mucosa and pharynx, and poppy tongue.
4. Polymorphic rash, mostly distributed on the trunk.
5. Terminal changes of the extremities: hard swelling and congestion of the hands and feet in the acute stage, and membrane-like peeling from the ends of the fingers and toes starting around 2 weeks.
6. Acute non-suppurative cervical lymph node enlargement.
The above 6 clinical manifestations, with 5 (fever as a necessary condition) can be diagnosed. If echocardiography or coronary angiography shows coronary artery dilatation or coronary artery aneurysm formation, the diagnosis can be made with only 4 items.
(D) Differential diagnosis
1. Various rash diseases: for example, scarlet fever, which may have fever, rash, prune tongue, and increased white blood cells. However, scarlet fever is mostly seen in school-age children, with diffuse flushing of the skin all over the body, a dense chicken skin-like rash with perioral pale circles, positive skin scarring signs, and effective treatment with sensitive antibiotics; also, exudative polymorphic erythema, which can also appear as a rash, initially as irregular erythema, which can then expand and blister in the center, with the rash being more common on the extremities and face and neck, gradually progressing to the proximal end, and in severe cases, the eyes In severe cases, the eyes, lips and pseudomembranes may appear.
2. Juvenile rheumatoid arthritis: the duration of the disease is longer, joint symptoms such as redness, swelling and heat pain is obvious, the rash mostly appears when the body temperature is high, and fades when the fever subsides. There is no obvious hard swelling of hands and feet and membranous peeling of finger and toe ends, and coronary artery dilatation is rare.
3. Acute purulent lymphadenitis: the lymph nodes in the neck are enlarged, the skin on the surface may be red, pressure pain is obvious, there may be other sites of infection foci, and treatment with sensitive antibiotics is effective.
4. Infantile polyarteritis nodosa: it occurs mostly in infants under 1 year of age, with fever, rash and conjunctivitis, and significant coronary changes in pathology, but with less morbidity than cutaneous mucosal lymph node syndrome, and effective glucocorticoid therapy, with additional immunosuppressive drugs if necessary.
5. Viral myocarditis: fever, rash, shortness of breath, pallor, arrhythmia and other symptoms may appear, but there are no characteristic changes in the hands and feet, the lesions are mainly in the myocardium, and the coronary artery changes are less than in cutaneous mucosal lymph node syndrome.
Treatment】
1. Acute phase treatment.
(1) Gammaglobulin: The incidence of coronary artery aneurysm can be reduced by using gammaglobulin within 10 days of onset. 2g/kg intravenous infusion once, or 1g/kg/d continuous intravenous infusion for 2 days. If the body temperature does not decrease after 24 hours of gammaglobulin administration or if the fever recurs after 24 hours of fever reduction, 1g/kg can be given once more.
(2) Aspirin: Early oral aspirin can control the acute inflammatory process, 30-100mg/kg/d in 3-4 oral doses for about 2 weeks, and reduce the amount to 3-5mg/kg/d when the blood sedimentation decreases to normal. 3-5mg/kg/d of pansentin is added for those with significant platelet increase.
(3) Glucocorticosteroids: Children with severe myocarditis can use hormones for a short period of time, but because hormones can destroy fibroblasts, affect coronary artery repair and promote coronary artery aneurysm formation, they are not used in other cases.
(4) Children with coronary aneurysm formation should limit their activities and avoid strenuous exercise.
2. Treatment in the recovery and chronic periods.
(1) If there is no cardiac involvement, aspirin can be stopped until 8 weeks; if there is coronary artery involvement, aspirin should be taken orally for at least one year, or even for a long time.
(2) If coronary artery aneurysm persists, concomitant administration of pentoxifylline may also be indicated.
(3) Giant aneurysms and/or coronary artery stenosis may be treated with additional warfarin for a long time.
(4) Thrombolytic therapy, such as urokinase and streptokinase, should be used when there is thrombosis in the coronary artery or myocardial infarction occurs.
(5) Surgical treatment: Children with longer-term coronary stenosis may be considered for coronary artery dilation with balloon catheter. If there is high occlusion of the left main branch of the coronary artery, high occlusion of the left anterior descending branch or high occlusion of multiple arteries, coronary artery bypass surgery is feasible. In cases of severe mitral and/or aortic valve insufficiency, valvuloplasty or replacement is performed.