In the United States, more than 200 cases were suspected by mid-May, including some 145 in New York; 186 confirmed cases were eventually diagnosed between 15 March and 20 May in 26 US states. As of 11 May 2020, five fatalities were reported (1 in France, 1 in the UK, 3 in the US). In peer-reviewed medical journals, case series and related studies of the new condition were rapidly reported from countries including the UK; Italy; Spain; France and Switzerland; France; and across the US, including New York. The emerging observations suggested somewhat greater variety in the severity of symptoms than was originally thought. The proposal of a new clinical entity during a pandemic also prompted scientific discussion about its possible distinction from Kawasaki disease, and the potential role of COVID-19.By 15 July, 342 confirmed MIS-C cases (including 6 deaths) had been recorded in the US across 36 states plus Washington DC. Most (71%) of the children were Hispanic/Latino or non-Hispanic Black people, and the CDC underlined the need to learn the reasons for such a preponderance. By 29 July, a total of 570 cases and 10 deaths had been reported across 40 states, Washington DC, and New York City.Until late May, no confirmed case had been documented outside the EU/EEA/UK and USA. No suspicious case had been observed in East Asia or Southeast Asia (or in Australia or New Zealand).
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.