Researchers report the emergence of a new, rare inflammatory condition in 58 children from the UK, which they believe is linked with SARS-CoV-2 infection.
The syndrome is similar to Kawasaki disease—a rare condition that causes inflammation of the blood vessels in children under 5 years. However, an analysis by clinicians and researchers in the UK suggests that the new syndrome is a separate condition, which they have called pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS).
Although there is currently no direct evidence showing that PIMS-TS is caused by COVID-19, 45 of the 58 children (78%) either had a positive test result for ongoing infection with the virus, or showed antibodies against the virus showing that they had been previously infected.
“As these cases have emerged in temporal association with the pandemic, a link with SARS-CoV-2 is likely,” write the researchers in the Journal of the American Medical Association.
The UK team characterized the main symptoms and markers of PIMS-TS in 58 children with symptoms who were admitted to 8 UK hospitals in March this year. They compared their symptoms to those of over 1177 children with Kawasaki disease and 37 with toxic shock syndrome admitted to European hospitals over the last 20 years.
In addition to most of the children having prior infection with COVID-19, 69% were of black or Asian ethnicity, 57% were female and only 7 had other health issues.
Notably, while PIMS-TS can be serious and there are some concerns about long-lasting cardiovascular damage in some children with the condition, it did respond well to anti-inflammatory immunoglobulin and steroid treatment—which is also used to treat children with Kawasaki disease.
“Our analysis has shown that this is indeed a new condition,” said Julia Kenny, M.D., consultant in pediatric infectious diseases and immunology at Evelina London Children’s Hospital. “Untreated, there is a risk of severe complications in very unwell children, but with early identification and treatment the outcome is excellent, with the children we are reviewing after discharge completely well.”
There are several key differences between the children who developed PIMS-TS and those with Kawasaki disease. Firstly, the average age of the children with PIMS-TS was older, the median age of the 58 children in the analysis was 9 years versus younger than 5 in children with Kawasaki disease. Secondly, they had a higher level of white blood cells known neutrophils and a higher level of C-reactive protein, which is produced by the liver when the body is undergoing inflammation. But a lower level of another type of white blood cell called a lymphocyte and lower platelets and red blood cells – resulting in more pronounced anemia.
Patients with PIMS-TS also had higher levels of fibrinogen, a marker of vascular injury, and of troponin – a marker linked to stroke that has also been observed to be high in adults with serious COVID-19. Children with PIMS-TS were also more likely to have abdominal pains and diarrhea alongside persistent fever, which is common to both conditions.
“The new condition, PIMS-TS, is extremely rare but it can make a child very ill, so it’s important to characterize the disease properly so we can provide close monitoring and the best treatment,” said Elizabeth Whittaker, MD, lead author on the analysis and a consultant in pediatric infectious diseases and immunology at Imperial College Healthcare NHS Trust in London.
The team cautions that the numbers in the analysis were very low, but hope that the criteria should help other clinicians to diagnose children with this condition and to make sure they are treated as quickly and effectively as possible.
“For any parents worried about their children, I would urge them to follow their usual instincts – whatever would normally prompt you to visit your GP or A&E with your child still applies here,” emphasized Whittaker.
The team plans to collaborate with other researchers around the world to collect a larger dataset about children with PIMS-TS and to further improve the information and treatment options available to these patients.