Thursday, March 19, 2015

What is Kawasaki disease > Health and Wellness.

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Kawasaki disease is a rare disease, cause unknown, self-limited and fever blisters, which primarily affects children, and producing important alterations of blood vessels.
Also known as Mucocutaneous lymph node syndrome, the disease was first described in 1961 by the Japanese physician Tomisaku Kawasaki; in 1965 the doctor Noburu Tanaka describes the presence of an aneurysm in the coronary artery of a child who died with the disease. Subsequently, the same doctor Kawasaki published the first series of fifty cases in 1967 and called him 'Pediatric acute febrile Mucocutaneous lymph node syndrome'.
Kawasaki disease is an acute vasculitis (acute inflammation of blood vessels) that presents with fever, rash on the skin type Exanthema, and involvement of the mucous membranes and lymph nodes. The main complication is the formation of aneurysms in the coronary arteries of the heart, which can cause a fatal outcome by sudden death.
This disease is especially prevalent in Japan, where you register a prevalence of 108 cases per every 100,000 children under five years of age, which translates into about five to six thousand cases a year. In United States the prevalence is much lower, about 10 cases for every 100,000 children under five that are not of Asian origin, because in children of Asian origin the prevalence increases to 44 cases for every 100,000 children under five years of age. In Europe it is five cases per every 100,000 children under five years of age.
The average age of presentation of Kawasaki disease is between three months and four years, with one incidence higher in winter and spring.

Causes of Kawasaki disease

So far, the cause of this disease is unknown; However, several scientific evidence have allowed to raise different hypothesis on the causal agent of the disease, among whom are mentioned:
  • Epstein-Barr virus.
  • Parvovirus B19.
  • Bacteria as Staphylococcus aureus and Streptococcus pyogenes by the production of toxins.
  • Lactobacillus casei.
  • Coronavirus NL-63.
  • Cytomegalovirus.
  • Mercury.
  • Exposure to certain products for carpet cleaning.
The pathophysiology of Kawasaki disease is characterized by an acute vasculitis that affects the arteries of medium, with a certain predilection for coronary arteries, although it can also affect the veins.
There are four phases that describe how occurs the Cardiac involvement in Kawasaki disease:
  • Phase 1: 0 to 10 days. Vasculitis of the innermost layer of the coronary arteries carrying oxygen and nutrients to the heart, with or without pericarditis, myocarditis, endocarditis (involvement of heart valves), or system by which the electrical signals of the heart is lead.
  • Phase 2: 11 to 25 days. Vasculitis in all layers of the arteries (panvasculitis), with the formation of aneurysms (the wall of the blood vessel dilatation, pathologic).
  • Phase 3: 26-30 days. Spontaneous remission of inflammation of vessels.
  • Phase 4: more than 40 days. Scarring and stricture (narrowing), with fibrosis of the territories that have been inflamed.

Symptoms of Kawasaki disease

· The majority of children with Kawasaki disease are taken to the doctor by a picture of prolonged fever. Children tend to be more irritable from what would be expected for the level of fever presenting. Fever appears abruptly, although they can exist some mild symptoms the days prior, such as irritability, vomiting, diarrhea, decreased intake, cough, runny nose, weakness, abdominal pain, and joint pain.

Phases of Kawasaki disease

· The evolution of the disease follows four stages:
Acute phase
· Begins suddenly with fever above 39 - 40 ° C, which can last several weeks and that does not respond to antibiotics or antipyretics. With adequate treatment, such as aspirin at high doses or intravenous immunoglobulins (antibodies that are administered to reduce the immune response of the patient), the fever would refer in less than 48 hours.
· In addition to fever, in this phase there may be other symptoms and signs such as irritability, bilateral conjunctivitis (with red eyes), redness and swelling of hands and feet, redness around the anus, red tongue with appearance of Strawberry by the prominence of the taste buds, disorders of internal organs such as liver, kidney or intestine, inflammation of the heart muscle (myocarditis) or inflammation of the membrane surrounding the heart (pericarditis).
· In 75% of cases there is an increase of the lymph nodes in the neck that are felt as nodules of approximately 1.5 cm in diameter. Symptoms in the skin and the lymph nodes are very evident in the acute phase, but may persist throughout stages.
Subacute phase
· It is a phase that begins when it descends the fever and can last several weeks. The characteristic signs of this phase are scaling that occurs in the skin around the fingers and the noticeable increase in cells that exist in the blood that facilitate coagulation which are called platelets.
· In addition, this phase develop aneurysms (such as small bags) in inflamed coronary arteries. The risk of sudden death in this phase is high as they can form clots from blocking the coronary arteries leading to myocardial infarction. The formation of thrombi in this phase is facilitated by the presence of coronary artery aneurysms and the existence of high numbers of platelets, which encourage clotting.
Phase of convalescence
· At this stage they are disappearing all the symptoms of the disease, usually until three months have passed from the beginning of the picture. The alterations seen in blood tests are also normalized.
· However, although smaller aneurysms of the coronary arteries may disappear, there is a risk that grow larger aneurysms. These aneurysms can break or thrombi can form inside. Both complications cause obstruction of the coronary arteries and lead to a myocardial infarction.
Chronic phase
· This phase is only important in those patients who have had cardiac complications, as they are complications they can last a lifetime. In the coronary aneurysms persist into adulthood and in some cases might break with serious consequences.

Diagnosis of Kawasaki disease

Specific tests for the diagnosis of Kawasaki disease is currently not available, and uses criteria based on which the affected present the greater part of the signs associated with this disease, but tests are performed to differentiate the pathology of others that have similar symptoms.

Clinical criteria for diagnosis of Kawasaki disease

More than five-day fever more four of the following five main criteria, without other cause that explains the disease:
  • Bilateral conjunctival injection.
  • Changes in lips and oral cavity.
  • Changes in the extremities.
  • Skin rash.
  • Cervical Lymphadenopathy.

Complementary examinations

  • Blood count: increased white blood cells (Leukocytosis) with immature forms (hockey sticks), increase in the number of platelets (thrombocytosis), moderate anemia.
  • Erythrocyte sedimentation rate (ESR) speed: accelerated.
  • Increase in C-reactive protein (CRP).
  • Urine test: presence of abundant white blood cells without bacteria (sterile pyuria).
  • Liver enzymes (GOT, GPT, GGT) high.
  • Reduction of sodium in the blood (hyponatremia).
  • Microbiological cultures in blood (blood), pharyngeal (throat), cerebrospinal fluid, bone marrow, feces (stool) and urine (urine) negative.
  • Cerebrospinal fluid cytology: increase in the presence of cells (pleocytosis).
  • Electrocardiogram (ECG): must be performed to observe the existence of changes in heart rhythm (arrhythmias), either to rule out ischemic myocardial (lack of irrigation in the heart), with alterations in the conduction of the electrical currents from the heart.
  • Echocardiogram: must evaluate the coronary arteries, and pericardial effusions can be observed (fluid around the heart), myocarditis, endocarditis.
  • Coronary angiography: study of imaging with contrast for angiography to assess the presence of aneurysms of the coronary arteries.

Differential diagnosis

This disease can be confused with other diseases, both infectious and non-infectious, and it is important that the clinician has clear diagnosis of this pathology in order to differentiate it from measles, Scarlet fever, toxic shock syndrome, Stevens-Johnson Syndrome, polyarteritis nodosa, syndrome of Reiter, leptospirosis, adenovirus, or drug intoxication, among others.

Treatment of Kawasaki disease

These are the key points in the treatment of Kawasaki disease:
  • Complete rest in bed and hospital admission.
  • Aspirin (acetylsalicylic acid): to reduce the fever. The aspirin acts as antiplatelet platelet, thus reducing the risk of thrombus formation, and also acts as an anti-inflammatory. The use of aspirin is maintained even when the patient has been discharged and is in his house, to last two or three months, or when the laboratory parameters return to normal.
  • Immunoglobulins (IVIG): antibodies that are administered intravenously in a single dose to decrease the inflammatory response of the immune system against the blood vessels.
  • Immunosuppressants like corticosteroids and Cyclosporine, will be considered in those patients that they do not respond adequately to the treatment described above.
  • Coronary diseases: if they occur, may be necessary intervention of acute myocardial infarction as revascularization, the use of fibrinolytic with streptokinase, Angioplasty with stent therapy, or even the need for a heart transplant if the patient falls in heart failure.
If the acute phase of the disease is effectively is accomplished by reducing the rate of heart disease to less than five percent.

Prognosis and complications of Kawasaki disease

Kawasaki disease is acute and self-limited; If it is at an early stage the prognosis is good, and within eight to ten weeks remission can be complete.
But if there is coronary involvement the prognosis may be unfavorable. These patients may develop thrombosis of the coronary arteries, aneurysms, stenosis, or narrowing in the post-aneurismas areas.
Other cardiovascular complications include fibrosis of the heart muscle, dysfunction of the heart valves, heart failure, arrhythmia, etc.
Regular monitoring of these patients after the acute phase of disease is essential, and must be performed by a multidisciplinary team that includes pediatricians, cardiologists, radiologists, haematologists and immunologists, among others. The patient's risk level is set by the degree of coronary and cardiovascular illness in general
Published for educational purposes
Health and Wellness

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