Video report by Martin Fisher
Two mothers from Chesterfield have launched a campaign to raise awareness of the "dangerous" Covid 19-related illness which almost killed their young sons just weeks apart.
Sarah Morris's seven-year-old son, Samuel, and Ganga Gnanaraj's son, Shenan, 11, both had mild bouts of coronavirus last year.
But within weeks the boys – who didn't know each other – were in hospital fighting Paediatric Inflammatory Multisystem Syndrome (PIMS).
Sarah said: "It was sheer terror, it was confusion, it was terror. There's no other word – it was terrifying."
Ganga recalls having to be physically supported by medics as she watched her son deteriorate.
"They said his health is really, really bad. He's really going downhill," she said.
Sarah said Samuel was not badly affected by the virus itself, but then developed symptoms including a high temperature, cracked lips, a rash and lethargy.
He became severely ill to the point of being unable to stand and ended up on intensive care.
Sarah said: "I'd spoken to three different doctors in three different settings.
"Each doctor was advised that he'd had Covid, and then we went on to talk about the symptoms and none of them made that diagnosis of PIMS. There needs to be more awareness for frontline staff."
Shenan was sent home twice from hospital despite having symptoms of PIMS, with one doctor misdiagnosing him with tonsillitis.
It was only when he was struggling to breathe and hallucinating that he was admitted to Chesterfield Royal Hospital.
Both boys are now recovering, but Sarah wants to see the track-and-trace system used to contact parents of children who've had Covid to make them aware of the dangers posed by PIMS.
What is PIMS?
Paediatric Inflammatory Multisystem Syndrome (PIMS) is a new condition that happens weeks after someone has had the virus that causes Covid.
It causes inflammation and swelling throughout the body which is one way your immune system fights off infection, injury and disease.
A blood test is used to help diagnose by looking at levels of inflammation in the body.
What causes it?
It is caused by the immune system which fights of the virus but then over-reacts to affect other parts of the body.
Research is being carried out all over the world to find out more about the illness.
The main symptom of PIMS is a high temperature that lasts for a few days.
You might also have other symptoms such as:
Tiredness and weakness
Tummy pain or cramps
Red and cracked lips
Swollen hands and feet
Peeling skin on your hands and feet
Muscle aches and pains
Diarrhoea and vomiting
Swollen neck glands
PIMS is treated with a combination of medicines.
Chesterfield MP Toby Perkins is backing the women's campaign.
He said: "I'm trying to make sure that across our health service there is an awareness that although coronavirus is generally survivable by children, almost always, that this follow up condition can be very dangerous indeed."
Derbyshire Clinical Commissioning Group said PIMS is "potentially serious but rare" and further work is needed to understand it and other post-covid conditions.
They added: "The CCG will be sharing details of the condition again with clinicians to maintain awareness."