On 17 April, weeks into the UK's coronavirus lockdown, three-year-old Marley Grix was admitted to hospital.
He'd been ill for a few days – since Easter Monday – but his condition had taken a turn for the worse.
Marley's mum, Hayley, feared his life was in danger and knew she had to act quickly.
"He'd started off complaining about his neck saying it hurt, but it didn't seem bad and I just thought that perhaps he had slept funny.
"But for the rest of the week, he just kept getting progressively worse. He had diarrhoea and stomach pain and a temperature. I was on the phone to the GP pretty much every day. Phoning, videoing."
On the Friday, Marley was very ill, and he had symptoms that were scaring Hayley.
"He was really tired and he had a roaring, high temperature that wouldn't go down. His neck glands were swollen.
"His hands and feet were bright red and his eyes were bloodshot. And he was breathing really fast. It was terrifying.
"I called the GP again, but decided to take him to hospital. I followed my gut instinct."
The doctors in the paediatric unit admitted Marley and started running tests to figure out what might be wrong.
They suspected a few possible causes, including a bad reaction to coronavirus.
Doctors around the UK have been warning about a rare but serious syndrome that could be linked to the pandemic virus.
Some of these very ill children have had a septic-shock type illness with a rash and difficulty breathing.
Health Secretary Matt Hancock has said that he is very worried about it and that experts are looking into this rare condition.
Marley's coronavirus test came back negative and his doctors are now treating him for atypical Kawasaki disease.
This is another rare condition that mainly affects children under the age of five. Children who develop it may be genetically predisposed to doing so.
The symptoms are like those seen when the body is trying hard to fight off an infection. Read More – Source