Most children who receive expert multidisciplinary care survive. In addition to respiratory distress, major complications that may need aggressive supportive care can include myocardial damage, acute kidney injury, and coagulopathy (thrombophilia). In some cases, sustained cardiac arrhythmias have led to haemodynamic collapse and need for extracorporeal membrane oxygenation (ECMO). Deaths have been recorded in a small minority (under 2%) of the cases reported. Occasionally, fatalities  have followed complications of ECMO. Some children exposed to COVID-19 also appear to have a less severe Kawasaki-like disease. Ventricular function often recovers before discharge from hospital (often after 6–10 days). Coronary artery aneurysms can develop even in the absence of Kawasaki-like features. Their frequency and severity is uncertain. So far, they have been recorded in 7% of reported cases. Long-term prognosis is unclear. Diagnosis
Diagnosis is by specialist clinical evaluation. Diagnostic suspicion may be raised by unexplained persistent fever and clinically concerning symptoms following exposure to COVID-19. Families need to seek immediate medical care, as the childs condition can deteriorate rapidly. Paediatricians first involvement is often in the emergency department. Early recognition and multidisciplinary referral to paediatric specialists (in intensive care, infectious diseases, cardiology, haematology, rheumatology, etc.) is essential. Examinations may include blood tests, chest x-ray, heart ultrasound (echocardiography), and abdominal ultrasound. Clinicians worldwide have been urged to consider this condition in children who display some or all the features of Kawasaki disease or toxic shock syndrome. Case definitions and guidance
A universally accepted case definition for this newly described syndrome has still not been agreed.
Multisystem inflammatory syndrome in children (MIS-C), or paediatric inflammatory multisystem syndrome (PIMS / PIMS-TS), or systemic inflammatory syndrome in COVID-19 (SISCoV), is a rare systemic illness involving persistent fever and extreme inflammation following exposure to SARS-CoV-2, the virus responsible for COVID-19. MIS-C is also recognized as a potential pediatric adverse event following COVID-19 vaccination. It can rapidly lead to medical emergencies such as insufficient blood flow around the body (a condition known as shock). Failure of one or more organs can occur. A warning sign is unexplained persistent fever with severe symptoms following exposure to COVID-19. Prompt referral to paediatric specialists is essential, and families need to seek urgent medical assistance. Most affected children will need intensive care.All affected children have persistent fever. Other clinical features vary. The first symptoms often include acute abdominal pain with diarrhoea or vomiting. Muscle pain and general tiredness are frequent, and low blood pressure is also common. Symptoms can also include pink eye, rashes, enlarged lymph nodes, swollen hands and feet, and "strawberry tongue". Various mental disturbances are possible. A cytokine storm may take place, in which the childs innate immune system stages an excessive and uncontrolled inflammatory response. Heart failure is common. Clinical complications can include damage to the heart muscle, respiratory distress, acute kidney injury, and increased blood coagulation. Coronary artery abnormalities can develop (ranging from dilatation to aneurysms).This life-threatening disease has proved fatal in under 2% of reported cases. Early recognition and prompt specialist attention are essential.