On Sunday the Paediatric Intensive Care Society UK (PICS) warned about a small rise in the number of cases of critically ill children, some who had tested positive for Covid-19, presenting "overlapping features of toxic shock syndrome and atypical Kawasaki disease with blood parameters."
In a statement sent over the weekend to medical professionals who look after critically ill children, PICS said "abdominal pain and gastrointestinal symptoms have been a common feature as has cardiac inflammation."
So what is Kawasaki disease and how worried should parents and carers be?
What is Kawasaki disease?
Kawasaki disease, also known as Kawasaki syndrome, is a rare childhood illness that causes the walls of the blood vessels in the body to become inflamed.
According to the UK's National Health Service (NHS), the condition -- also known as mucocutaneous lymph node syndrome -- mainly affects children under the age of 5, although it can affect children of any age.