The World Health Organization called on doctors around the globe to look into a rare illness in children that could be associated with the novel coronavirus.
"I call on all clinicians worldwide to work with your national authorities and WHO to be on the alert and better understand this syndrome in children," WHO Director-General Tedros Adhanom Ghebreyesus tweeted on Saturday.
The organization released a scientific brief on the emerging condition, which it is calling "multisystem inflammatory syndrome in children and adolescents."
WHO defined the syndrome as occurring in children under 19. Symptoms include a fever that lasts three days or longer, rash, inflammation, hypotension or shock, and gastrointestinal problems, among other things.
"We need more information collected in a systematic way because with the initial reports, we're getting a description of what this looks like, which is not always the same," Maria Van Kerkhove of WHO said during a press briefing on Friday. "And in some children, they tested positive for COVID-19 and other children have not. So we do not know if this is associated with COVID-19."
The brief is similar to one put out by the Centers for Disease Control and Prevention earlier this week, but the CDC definition includes patients up to 21 years of age and said that it is not known whether the syndrome also occurs in adults.
The brief underscored the need to "characterize this syndrome and its risk factors, to understand causality, and describe treatment interventions. It is not yet clear the full spectrum of disease, and whether the geographical distribution in Europe and North America reflects a true pattern, or if the condition has simply not been recognized elsewhere."