Kawasaki Disease
Kawasaki disease (KD) is a rare syndrome which causes vasculitis that primarily affects the heart. This disease causes inflammation in the walls of medium-sized arteries throughout the body, and principally affects children under the age of five (although it can be present in older patients). The inflammation tends to primarily affect the coronary arteries, which supply blood to the heart muscle. Kawasaki disease is sometimes called mucocutaneous lymph node syndrome because it also affects lymph nodes, skin, and the mucous membranes inside the mouth, nose and throat. With effective diagnosis and treatment, only a small percentage of cases have any lasting damage.
Causes and Risk Factors
There is no clear consensus on what exactly causes Kawasaki disease, although it is known that it cannot be spread from human to human. A number of theories link it to an immune response to a virus or other environmental factor. Some researchers suggest coronavirus may have a role in Kawasaki disease. Certain genetics may increase a child’s susceptibility to KD. In addition, there seems to be a seasonal cause, as the peak incidence rate is from January through March. Male children have a higher incidence rate than female children, and individuals of Asian descent are 20 times more likely to develop Kawasaki disease than Caucasians. Some recent evidence suggests a combination of genetic factors. Approximately 65 in 100,000 children are hospitalized each year for KD, and the numbers are on the rise.
Symptoms
Initial symptomatology is that of any viral or bacterial infection. There is a progressive fever that lasts more than three days and up to 11 days. Onset of symptoms is usually very rapid. Temperatures may reach 104-5 degrees Fahrenheit and are refractive to antipyretics such as acetaminophen. Conjunctivitis without a thick discharge usually ensues, causing the eyes to be watery and itchy. If the child is verbal they may complain of a sore throat, and in a non-verbal child you may notice grimacing when swallowing. Lymphatic nodes in the neck will be swollen and tender.
The hallmark of the disease manifests as a rash on the torso and in the genital and anal area. The rash may then progress to the palms and sole of the feet. It may also invade the mucus membranes of the mouth and tongue, which gives the tongue a strawberry red color. Due to the age of the child they may become irritable, sleepless, lethargic and/or inconsolable.
Sub-acute or Second Phase
This phase usually begins around day 12 and lasts through day 21. Complications are most likely to occur during this stage and the child will become more irritable and may appear in pain with movement. Other symptoms are:
abatement of the fever
peeling of the skin, especially on the fingers and toes, often in large sheets
joint pain
diarrhea
vomiting
concurrent otitis media
abdominal pain
swollen lymph nodes that may progress to groin and axilla
hepatomegaly and splenomegaly
aseptic meningitis
cardiac involvement (see treatment section)
Convalescent or Third Phase
In the third phase of the disease, signs and symptoms slowly go away unless complications develop. It may take as long as two to three months for energy levels to seem normal again. Continuing evaluation for cardiac complications may go on for a year or more.
Diagnosis
There is no specific test to confirm Kawasaki disease. Diagnosis is usually made on four or more proven symptoms and physical exam. Since the symptoms are similar to other childhood diseases, including the measles, scarlet fever, toxic shock syndrome, and juvenile arthritis, additional tests may be ordered to eliminate suspicion of those diseases. Much of the blood work will not be definitive, but may help support the diagnosis. Within this test, patients with KD may present with:
elevated platelet count- conversely, low counts (thrombocytopenia) are a higher risk for severe cardiac disease
elevated white blood cell count
low hemoglobin and erythrocytes
elevated erythrocyte sedimentation rate (ESR)
elevated C-reactive protein (CRP)
hyponatremia
low serum albumin- indicative of a poor prognosis
elevated alpha1-antitrypsin levels
elevated serum CK-MB
urine with increased leukocytes and protein
Due to the potential for severe cardiac involvement, all patients with a tentative diagnosis should have an electrocardiogram and echocardiogram.
Treatment
Treatment for KD is hospitalization with drug therapy and monitoring as soon as a diagnosis is made to prevent complications. The current standard is the use of intravenous immunoglobulin (IVIG). Evidence indicates that, when given within the first 10 days of onset, IVIG reduces the incidence of coronary artery abnormalities (aneurysm) from about 20% in patients receiving aspirin alone to 3-4%. A single high dose of IVIG (2 g/kg) is the gold standard therapy in the acute stage of KD. Should the patient not respond as thought, a second infusion may be necessary. Fever was the most common manifestation of a side effect and occurred within 1 to 6 hours from the onset of infusion of IVIG. Side effects were affected by fast infusion rates and managed by reducing the rate of infusion.
Aspirin
KD leads to a very high blood platelet count, and a higher risk of clots forming in the bloodstream, specifically the coronary arteries. Aspirin helps prevent blood clots and reduces the fever, the size of the rash, and joint inflammation. A high dose will normally be necessary during the acute phase, usually 80–100 mg/kg per day. This is one of the few times that aspirin is used in the pediatric population. Due to a small risk of Reye’s syndrome during outbreaks of influenza and chickenpox, health care providers should recommend annual influenza and chicken pox vaccinations for children who require long-term aspirin therapy.
Corticosteroids, thought to be the standard treatments for vasculitis, are in a state of flux when it comes to KD. The use of systemic steroids at this time is not common practice, but ongoing research will hopefully clarify the course of treatment. The only use of steroids at this time is the use of topical steroids for the uveitis (conjunctival complications) of KD and topical use for skin irritation. Although uveitis generally resolves within days of intravenous immunoglobulin therapy, conjunctival inflammation also may be treated with topical corticosteroids, preservative free tears, ointments, and cool compresses.
Cardiac complication
Generalized vasculitis can permanently damage a child’s heart. Inflammation of the coronary arteries can lead to weakening and bulging of the artery wall (aneurysm). Aneurysms increase the risk of blood clots forming and blocking the artery, which can lead to a heart attack or cause life-threatening internal bleeding. KD can cause low cardiac output and heart failure. In some cases, pericarditis and the leakage of aortic and mitral valves can cause heart failure.
During the subacute phase, a lower dose of aspirin is typically given for its antiplatelet effect to help prevent blood clots from forming. Such therapy may be continued for up to eight weeks after onset in children without abnormalities detected by echocardiography. Some cardiologists may advise that aspirin therapy be continued in perpetuity for those with coronary artery changes. Individuals who have multiple or large coronary aneurysms may also receive therapy with anticlotting medications, such as low molecular weight heparin. The use of warfarin is not tolerated well in the pediatric population, and therefore is not recommended.
Nursing care of the KD child should therefore include:
Continual cardiac monitoring and assessment for complications
Assess and report signs of cardiac failure or arrhythmias, chest pain, changes in intake and output, edema, distended neck veins, or chest pain
Monitor for respiratory heart failure including dyspnea, nasal flaring, grunting, retractions, cyanosis, orthopnea, and moist or crackling respirations
Monitor hydration status by checking skin turgor, weight, urinary output, specific gravity, tears, and ability to take oral fluids
Ensure uninterrupted rest
Avoid NSAIDS if the child is on aspirin therapy, while addressing pain levels and treating appropriately
Darken room and apply cool compresses to eyes as tolerated
Provide oral care as needed for chafed lips or sore through with ice, jelly and salves
Maintain nutritional balance by offering fluids/soft food hourly
Practice relaxation techniques with child, such as relaxation breathing, guided imagery, and distraction
Prepare the child for cardiac surgery or thrombolytic therapy if complications develop
Keep the family informed about progress and reinforce stages and prognosis. Rarely in a parent’s life are they more frightened than when a severe or debilitating disease affects their child. The nurse must be supportive and nonjudgmental as to how parents, siblings and others respond to this rare syndrome.
Conclusion
Almost all the morbidity and mortality occur in patients that develop aneurysms. Risk of myocardial infarction from coronary artery thrombosis is greatest in the first 2 years after illness onset. However, stenosis and occlusion progress over years. In rare cases, coronary artery bypass surgery or heart transplantation is recommended for children with severe cardiac involvement.
KD is a leading cause of acquired heart disease in children, but with effective treatment, only a small percentage of children have lasting damage. For a very small percentage of children who develop coronary artery problems, however, Kawasaki disease can be fatal, even with treatment.
References:
Kawasaki Disease. Retrieved from https://rarediseases.org/rare-diseases/kawasaki-disease/.
Kawasaki Disease. Retrieved from https://www.nhlbi.nih.gov/health/health-topics/topics/kd.
Newburger, JW et. al. (2016). Kawasaki Disease. JACC, 67 (14), 1738-1749. Retrieved from https://www.clinicalkey.com/#!/content/journal/1-s2.0-S0735109716007130.
Weng, Ken-Pen et. al. (2011). Recent advances in the treatment of Kawasaki disease. Journal of the Chinese Medical Association, 74 (11), 481-484. Retrieved from https://www.clinicalkey.com/#!/content/journal/1-s2.0-S1726490111002279.
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