What does the medical alert say? Doctors have picked up a slight rise in the number of children of all ages needing intensive care treatment for a condition called “multi-system inflammatory state”. The rise has happened over the past three weeks in London and elsewhere in the UK. The notice was first issued to GPs in North London and confirmed in an “urgent alert” on Sunday night from the Paediatric Intensive Care Society. Is it related to Covid-19? That is the concern, but doctors don’t know. Hospitals have seen it in children who have tested positive and negative for the coronavirus, but test results are not 100% reliable. It may be a rare coronavirus-related inflammatory syndrome that has taken time to come to light, or it may be caused by another pathogen entirely. The NHS said it was important for clinicians to be aware of any emerging links so they can give children the right care quickly. What is a multi-system inflammatory state? It’s a severe immune response that can affect the body in multiple ways, most importantly by making the blood vessels leaky, a condition called Kawasaki disease. This leads to low blood pressure and a build-up of fluid in the lungs and organs. It is extremely serious. Patients need urgent intensive care to support the heart, lungs and sometimes other organs such as the kidneys. Are there other symptoms? The children have overlapping symptoms of toxic shock syndrome (another extreme immune reaction) and unusual Kawasaki disease. But other symptoms have also been observed in children, including abdominal pain, gastrointestinal problems and heart inflammation. There is no evidence that the condition is caused by any change in the virus, as that would have shown up in adults first. But it may be a post-infection inflammatory response triggered by the coronavirus. This has been seen in adults, who tend to be more ill in the second phase of the infection, when the initial lung disease gives way to inflammatory damage. Is it common? No. There are only a dozen or so cases nationwide. The alert is intended to raise awareness of the symptoms among GPs and paediatricians so that cases are referred quickly, and so doctors can build up a better picture of what may be causing the illness. Despite the virus spreading around the world, scientists are still getting to grips with how it works. In adults, Covid-19 is an inflammatory disease that can affect different organs, but children have tended to have far milder infections. Has public advice changed? No. The Royal College of Paediatrics and Child Health said parents should be reassured that children are unlikely to be seriously ill with Covid-19. The NHS urged parents who are worried about a child to contact NHS 111 or their family doctor for urgent advice, or call 999 in an emergency.