The disease is the leading cause of acquired heart disease in children under five in the UK, and can be fatal if not treated in time.
In 2020-2021, 706 children received treatment for Kawasaki disease — more than double the average of 336 children a year for the previous five years.
Because of the increase, the NHS is calling on more people to donate plasma.
Plasma is used to make immunoglobulin, a medicine used to treat the disease.
To meet demand, the health service is looking to increase the number of plasma donors from 5,850 to 10,200.
Health minister Neil O’Brien said donors could save someone’s life.
“More plasma donors are needed to treat Kawasaki disease and we are working closely with NHS Blood and Transplant to boost supplies so we can provide the best possible care to patients,” Mr O'Brien said.
“Thank you to existing donors who have generously come forward. If you can, please consider donating blood or plasma. It could save someone’s life.”
Gerry Gogarty, director of plasma for medicine at NHS Blood and Transplant, said: “There is a rising need for plasma donors to help treat life-threatening immune disorders such as Kawasaki disease.
“You can help by donating plasma or blood. You have a medicine in you.”
In 2021, the government lifted a two-decade ban on donations of plasma in England for use in making medicine after accepting updated advice from the Medicines and Healthcare products Regulatory Agency.
Members of the public can donate plasma in Birmingham, Reading or Twickenham. Plasma is also recovered from normal blood donations.