A new coronavirus-related syndrome impacting children could be emerging in the UK, the National Health Service (NHS) has warned.
NHS England has sent an urgent alert to GPs warning that over the previous three weeks there has been a rise in children presenting with a "multi-system inflammatory state requiring intensive care".
The Paediatric Intensive Care Society (PICS) added that children show symptoms of toxic shock syndrome — which is caused by a bacteria getting into the body and releasing harmful toxins — and atypical Kawasaki Disease "with blood parameters consistent with severe COVID-19 in children".
Kawasaki disease primarily affects children under the age of 5 and can cause blood vessels to become inflamed and swollen and lead to complications in the blood vessels that supply blood to the heart.
"There is a growing concern that a Sars-CoV-2-related inflammatory syndrome is emerging in children in the UK."
But the warning also suggested that "there may be another, as yet unidentified, infectious pathogen associated with these cases."
Abdominal pain and gastrointestinal symptoms and cardiac inflammation are common features of the infection.
It is unclear how many children have so far been affected and whether any have died.
Prof Simon Kenny, NHS national clinical director for children and young people, said in a statement that "thankfully Kawasaki-like diseases are very rare, as currently are serious complications in children related to Covid-19, but it is important that clinicians are made aware of any potential emerging links so that they are able to give children and young people the right care fast.".
Professor Russell Viner, President of the Royal College of Paediatrics and Child Health, also stressed that instances of children falling severely ill with COVID-19 have been "very rare".
"Evidence from throughout the world shows us that children appear to be the part of the population least affected by this infection.
"New diseases may present in ways that surprise us, and clinicians need to be made aware of any emerging evidence of particular symptoms or of underlying conditions which could make a patient more vulnerable to the virus," he added.
Both clinicians said their advice "remains the same" and that parents should seek help from medical professionals if they're worried about their children.
According to NHS data, only 1,523 of the more than 99,000 confirmed cases of COVID-19 recorded in the UK between January 31 and April were of children below the age of 19.