UK teen dies of Kawasaki-like disease linked to coronavirus
The teenager was part of a cluster of eight cases treated at the Evelina London Children's Hospital over a 10-day period in April, according to a report by his medical team published in The Lancet journal.
The 14-year-old spent six days in intensive care at the Evelina and tested positive for COVID-19 following his death, said the team.
The hospital has seen around 50 children with the illness, according to medical director Sara Hanna, with around half since discharged.
The British Health Secretary Matt Hancock said last month that experts are investigating the new syndrome in children "with great urgency" but stressed it is rare.
The condition is said to be similar to Kawasaki disease, which mainly affects children under the age of five, with symptoms including a high temperature, rashes, swelling and a toxic shock-style response.
Hanna, who is a consultant in children's intensive care, said those with the illness have a "reasonably long stay in hospital", with some admitted for up to three weeks.
"The majority are in high dependency, so not the highest level of intensive care," she told the PA news agency.
"We have got a handful of children in intensive care but they are not currently requiring the highest levels of support, which is good as some of the children we have had prior to this have been much sicker."
The youngest child in the cluster of cases was four, according to the report.
Two of the children in the group, including the boy who died, were obese.
The report added that six were of Afro-Caribbean descent, and five of the children were boys.