Author
Barbara Chernow, MA, PhD
Medical Writer
Medscape from WebMD
New York, NY
Disclosure: Barbara Chernow, MA, PhD, has disclosed no relevant financial relationships.
Editor
Richard S. Krause, MD
Senior Faculty
Department of Emergency Medicine
State University of New York at Buffalo School of Medicine
Buffalo, New York
Disclosure: Richard S. Krause, MD, has disclosed no relevant financial relationships.
Kawasaki disease is a vasculitis of unknown cause that primarily affects children. It was first identified in 1967 by Tomisaku Kawasaki. The diagnosis is based on a temperature greater than 39°C for at least 5 days combined with at least 4 of the following features: rash, swelling of the hands and feet, bilateral conjunctival injection, anterior cervical adenopathy, and inflammation of the lips and oral cavity. Because Kawasaki disease affects the lymph nodes, mouth, and mucous membranes, it is also known as "mucocutaneous lymph node syndrome." In some cases, not all of the diagnostic criteria are present, leading to the diagnosis of incomplete Kawasaki disease.
Kawasaki disease was at first thought to be a benign illness. However, thrombotic occlusion of acquired coronary artery aneurysms with myocardial infarction (MI) was found to be the immediate cause of death in patients with this condition, and Kawasaki disease is now the leading cause of acquired heart disease in children. The chart above shows the clinical manifestations of the disease and the typical time progression for their appearance. Kawasaki disease is usually treated with intravenous immunoglobulin and aspirin, but anticoagulants and antiplatelet agents may be used if an aneurysm is present. Coronary intervention may be needed in cases of coronary occlusion.
The clinical presentation of Kawasaki disease can be divided into 3 stages. The acute stage begins with the onset of fever and lasts 1 to 2 weeks. This is followed by the subacute stage, which includes desquamation of the extremities and the development of coronary aneurysms. The third stage is convalescence, during which the findings resolve. The patient may first exhibit erythema of the palms, soles, and perineal regions that gradually spreads to the trunk and extremities. Within the first few days following the onset of fever, more than 90% of patients present with a polymorphic rash. The patient in this image presents with patchy macular erythema, an abnormal redness of the skin. Note that the eruptions are not blisterlike. From here, the disease spreads to the perineal region (see next slide).
A few days after the appearance of the eruption shown in the previous slide, the disease may affect the perineal region. The patient on the left exhibits desquamation of the perineal region. The patient on the right presents with an erythematous rash involving the perineum. Image on right courtesy of Wikipedia.
In 94% of cases, the patient experiences changes in the extremities. After the appearance of erythema, the palms of the hands and soles of the feet become abnormally indurated and swollen. The patient on the left shows erythema of the palms, which may be accompanied by painful edema of the dorsa. The patient on the right presents with erythema of the soles and swelling of the dorsa of the feet. The presence of induration and painful swelling affects the patient’s quality of life by limiting mobility. Images courtesy of Wikipedia.
In the subacute phase of the illness, approximately 2 weeks after the onset of the initial fever, 75% of patients have acral desquamation (peeling) and erythema (redness and inflammation) of the fingertips that first involves the periungual (nail) region of the fingers. About 7 days later, similar desquamation of the toes occurs.
In Kawasaki disease, oral manifestations also appear within the first few days after the onset of the fever. In 50% to 77% of cases, patients experience an erythematous tongue. Referred to as “strawberry tongue.” this manifestation is characterized by redness and swelling, prominent papillae, and vertical cracking and bleeding. By itself, strawberry tongue is insufficient for a diagnosis of Kawasaki disease, as this symptom can also appear in patients with scarlet fever, which is a streptococcal infection.
In addition to strawberry tongue, patients exhibit other changes in the oral cavity. In 75% to 90% of cases, patients present with red and swollen lips that crack and bleed, as well as pharyngeal erythema. In this image, note the combination of manifestations in the lips and hands. The patient is still in the subacute phase of the illness.
A classic criterion for diagnosing Kawasaki disease is bilateral bulbar conjunctival congestion. This manifestation appears within a few days of the onset of fever and affects approximately 88% of patients. As shown in the image, the patient has red and swollen eyes, with no indication of pus or drainage and relative sparing of the limbus. This condition usually lasts several weeks. The patient may also present with mild iridocyclitis, anterior uveitis, superficial punctate keratitis, vitreous opacities, papilledema, and subconjunctival hemorrhage.
Kawasaki disease is best diagnosed clinically by evaluating the patient’s manifestations and symptoms. No laboratory testing or imaging can confirm the condition, especially during its early stage. Other illnesses, such as scarlet fever, toxic shock syndrome, and juvenile arthritis, mercury poisoning, can result in similar symptoms. In addition to the manifestations shown in slides 2 through 9, other symptoms of Kawasaki disease include diarrhea, vomiting, abdominal pain, pneumonitis, arthralgias, and general irritability. In addition, within 2 weeks of the onset of the illness, the patient may present with gallbladder hydrops. This may be the result of periportal inflammation that travels to the cystic duct. This sonogram of the right upper quadrant shows gallbladder hydrops, which can contribute to the diagnosis.
The most dangerous complication of Kawasaki disease is vasculitis of the coronary arteries, which can lead to coronary artery aneurysms, thrombosis, and myocardial ischemia or infarction. Contrast angiography remains the gold standard for diagnosing coronary aneurysms, but current practice is to perform angiography only after an aneurysm is detected on echocardiography. This angiogram shows aneurysmal dilation of the coronary vessels.
Although 10% to 18% of children with Kawasaki disease develop the aneurysm, most cases of aneurysm occur in patients whose treatment is delayed. Aneurysms can lead to myocardial infarction even in young children. As a result of this complication, Kawasaki disease is now the most common cause of acquired heart disease among children in the United States, with rheumatic fever ranked second. Early treatment of the symptoms of Kawasaki disease results in quick recovery and a significant reduction in the incidence of coronary aneurysms. Approximately 2% of patients with Kawasaki disease die of coronary complications. Patients with Kawasaki disease should be screened with echocardiography every 1 or 2 years after recovery. This image shows a 3-dimensional volume rendering from multidetector computed tomography of a large right coronary artery aneurysm (arrow). Subtraction of the myocardium in B shows the fistula draining to the coronary sinus and then into the right atrium.
Author
Barbara Chernow, MA, PhD
Medical Writer
Medscape from WebMD
New York, NY
Disclosure: Barbara Chernow, MA, PhD, has disclosed no relevant financial relationships.
Editor
Richard S. Krause, MD
Senior Faculty
Department of Emergency Medicine
State University of New York at Buffalo School of Medicine
Buffalo, New York
Disclosure: Richard S. Krause, MD, has disclosed no relevant financial relationships.