On the Paediatric Ward

Last April, we began to see children admitted to hospital with a new inflammatory disease. Paediatric inflammatory multisystem syndrome temporally associated with Sars-CoV-2 infection (abbreviated to PIMS-TS in the UK or MISC-C in the US) can occur two to six weeks after an initial Covid-19 infection. Many of the children will have been asymptomatic, or have had very mild symptoms, and Covid swabs usually come back negative when they present with PIMS-TS. Antibody tests might show evidence of a recent Covid infection, but hospitals are not routinely testing for Covid antibodies. The symptoms were initially attributed to other inflammatory conditions. News began to come in from other parts of the world, however, confirming that what we were seeing was a novel illness. Cases have been rising again over the last two months.

The symptoms of PIMS-TS can vary but children usually present with a persistently high fever associated with abdominal pain, diarrhoea or vomiting; rashes; conjunctivitis; and muscle aches. In severe cases we see signs of shock, such as a rapid heart rate and low blood pressure. These symptoms look like many other conditions and early cases were thought to be atypical versions of Kawasaki disease, which is caused by inflammation of the blood vessels and is associated with prolonged fever, rashes, red cracked lips, conjunctivitis, swelling and peeling skin on hands and feet, and swollen lymph nodes.

Most children with PIMS-TS have some but not all of the features of Kawasaki’s; PIMS-TS can also look like toxic shock syndrome (caused by bacterial infections such as staphylococcus) or appendicitis. Some children underwent surgery for appendicitis only for us later to discover that their symptoms were due to PIMS-TS. Unlike adults with severe Covid, children with PIMS-TS do not tend to get respiratory symptoms; but like adults with Covid, they are often critically unwell. The inflammation is targeted not at a pathogen but at the body’s own cells, and can attack several different systems.

Current estimates suggest that PIMS-TS affects one in five thousand children who get Covid. It has been reported that during the most recent wave, between twelve and fifteen cases a day were being admitted to UK hospitals. In the first wave, many of them needed to be transferred to paediatric intensive care units or specialist centres. Since then a consensus on symptoms, investigations and management issued by the Royal College of Paediatrics and Child Health, and guidelines from paediatric hospitals, have led to earlier detection and more efficient treatment, meaning children can often be cared for in their local hospitals (in consultation with specialist centres). As with Covid-19 in adults, PIMS-TS seems to affect BAME children disproportionally: they account for between 50 and 75 per cent of reported cases. There seems to be a slightly higher incidence in boys compared to girls (a ratio of 3:2). Unlike Kawasaki disease, which usually affects the under-fives, PIMS-TS affects children of all ages and the vast majority have no underlying health conditions.

There is no single diagnostic test for PIMS-TS. It’s helpful, of course, to know whether a child has contracted or been exposed to Covid – information that was often lacking in the first wave. We run blood tests to look at levels of inflammation in the body, signs of infection, clotting and damage to the heart. Ultrasounds rule out other causes of abdominal pain. An ECG and echocardiogram are essential as up to a third of patients develop coronary aneurysms and arrhythmias. The children tend to look very unwell from admission, lying listless in their beds or in lots of pain. Some, however, can start out looking quite well but quickly deteriorate. Those of us who have seen many children with PIMS-TS have come to recognise the pattern of symptoms.

There are ongoing trials to see which treatments work best. Current management is similar to that for many inflammatory conditions: measures to dampen the immune system, including steroids and intravenous immunoglobulin (pooled antibodies from blood donations); aspirin to prevent clots forming. Inotropes (to increase blood pressure) can be necessary to ensure a good oxygen supply to the vital organs of children in shock, and three children in the first wave required extracorporeal membrane oxygenation (ECMO), a machine only used for the sickest patients, which takes over the role of the heart and lungs.

The severity of PIMS-TS, despite its rarity, raises questions about national Covid policies. In the first wave two children died of PIMS-TS. We do not yet know the long-term effects, but children unwell enough to be admitted to intensive care, particularly those that develop aneurysms, may continue to have further complications. There are currently no plans to immunise children against Covid, although a trial of the Oxford/AstraZeneca vaccine in children has just started.

The other Covid policy seriously affecting children is the closure of schools. It has undoubtedly reduced the spread of Covid and protected the elderly and clinically vulnerable. It has almost certainly reduced the number of children developing PIMS-TS. The health impacts of missing school, however, are huge. We have seen children coming to hospital at a far later stage of illness than they ordinarily would, because parents are worried about exposing their children to Covid in hospital, or don’t want to overburden the health service.

The number of children attempting suicide or self-harm, or being admitted to hospital with depression and anxiety, has gone up significantly. I see children who have harmed themselves nearly every day. They cite the lack of school, friends and extracurricular activities as causes of low mood and suicide ideation. The school closures also affect children’s physical health; many children rely on school meals for nourishment. There are also significant concerns among paediatricians that children who suffer abuse at home no longer have the respite of school and aren’t being seen by adults, such as teachers, who might notice signs of abuse.

We still have a lot to learn about PIMS-TS. We don’t know if there are predisposing genetic factors or what the best way of treating it is. We don’t know the long-term effects. Nor have we begun to reckon with the serious social and psychological impact on children of living through a pandemic, experiencing the world at a standstill, and spending all day at home.