askST: How does a child develop multi-system inflammatory syndrome from Covid-19?

MIS-C is a condition where the child's immune system overreacts after a Covid-19 infection, typically two to eight weeks later. ST PHOTO: KELVIN CHNG

SINGAPORE - A rare condition where different organs in the body are inflamed has been found in some children infected with Covid-19.

A child with multi-system inflammatory syndrome in children (MIS-C) may require urgent care due to the involvement of various vital organs such as the heart, lungs, kidneys, brain, skin and eyes.

The condition is the subject of ongoing research, with attempts to identify risk factors.

Some experts believe that Covid-19 antibodies produced by the child following an infection results in the development of this syndrome, while others say genetic factors may be at play.

While giving an update on Monday (Nov 15) on the pandemic situation in Singapore, Associate Professor Kenneth Mak said a sixth MIS-C case has been detected.

The cases are aged two months to 11 years old. Three have recovered, Prof Mak, Singapore's director of medical services, added.

Of the remaining three children, one has been transferred to the general ward from the paediatric intensive care unit. He may be discharged soon if his recovery remains uneventful.

The Straits Times answers some of the questions about MIS-C as more details emerge about the condition among Covid-19 child patients in Singapore.

Q: Must the child be infected with Covid-19 to develop MIS-C?

A: MIS-C is a condition where the child's immune system overreacts after a Covid-19 infection, typically two to eight weeks later.

"It is speculated that Covid-19 antibodies produced by the child following an infection results in the development of this syndrome," said Associate Professor Thaschawee Arkachaisri.

The senior consultant heads the paediatric rheumatology and immunology department at KK Women's and Children's Hospital (KKH).

He added: "According to the definition set by the World Health Organisation (WHO) and the Centre for Disease Control and Prevention (CDC), there must be a Covid-19 association before a MIS-C diagnosis can be given."

Q: What is the difference between MIS-C and Kawasaki disease?

A: MIS-C has symptoms similar to Kawasaki disease, which has been linked to various viral or bacterial infections and occurs in 150 to 200 children a year in Singapore.

Kawasaki disease is an illness that results in inflammation in blood vessels throughout the body and mostly affects children younger than five years old.

Paediatric immunologist Liew Woei Kang told ST that although MIS-C and Kawasaki disease may share overlapping clinical features, studies in the United States indicate MIS-C can affect a wider age range.

Children with MIS-C also tend to have more prominent gastrointestinal and neurological symptoms, present more frequently with low blood pressure and are more likely to display cardiac dysfunction than children with Kawasaki disease.

Prof Arkachaisri echoed the point made about MIS-C patients having more gastrointestinal symptoms.

"They are also at higher risk of low blood pressure, reduced level of certain white blood cells and blood platelet count," he added.

Associate Professor Chong Chia Yin, senior consultant in infectious diseases at KKH, said the hospital found no MIS-C cases among more than 280 paediatric Covid-19 patients admitted to KKH last year.

Since 2020, KKH has been serving as the primary hospital looking after paediatric cases in the current pandemic.

Prof Chong noted that the hospital has not seen Covid-19-related cases of Kawasaki disease, adding: "The number of Kawasaki disease cases also declined... and none of the Kawasaki disease cases fulfilled the MIS-C criteria defined by WHO and CDC."

SPH Brightcove Video
Four children infected with Covid-19 in S'pore have been diagnosed with multi-system inflammatory syndrome in children, known as MIS-C.

Q: Who is at risk of developing MIS-C and what signs and symptoms should parents look out for in their children to get timely medical attention?

A: Prof Arkachaisri said parents should not be overly concerned because the syndrome is treatable if detected early.

He added that most patients, such as those treated at KKH, make a full recovery and lead normal lives.

Nonetheless, parents should be vigilant for MIS-C if their child has a history of close contact, is infected or had been infected with Covid-19.

Severe symptoms that may indicate MIS-C include difficulty in breathing, persistent pain or pressure in the chest, vomiting, abdominal pain, acting unusually sleepy or confused, feeling unusually weak or dizzy, looks pale, has grey or blue-coloured lips.

Q: Where should parents or guardians bring their children if they suspect their children has MIS-C?

A: Prof Arkachaisri said parents should seek the care of a paediatrician or children's emergency care immediately if the child develops severe symptoms.

"The affected child will need to be treated in a specialist children's hospital such as KKH, since some will require intensive care."

Q: What are some precautions parents can take to guard against MIS-C?

A: As the mechanism of how Covid-19 triggers MIS-C is still under study, preventing Covid-19 infection is the best strategy to guard against MIS-C.

Thus, Prof Arkachaisri recommends complying with strict hygiene standards, such as washing hands with soap and water, avoiding contact with people who are sick and regular disinfection of high-touch surfaces.

"It is also recommended for children to take the Covid-19 vaccination when it is made available to them."

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