Children and adolescents with a post-COVID-19 systemic hyperinflammatory syndrome have been reported in Victoria and NSW in association with the current Delta variant.
PIMS-TS is rare but potentially life threatening. Early recognition and discussion with appropriate specialist teams is important.
Advice for clinicians
Medical, surgical, and emergency staff who see children should consider PIMS-TS in:
- any child or adolescent with the typical features of fever, abdominal pain, rash and tachycardia. Cases can mimic acute appendicitis.
- younger children with more typical Kawasaki disease-like features, especially if they have gastrointestinal features and/or signs of shock.
If you have a patient with possible PIMS-TS, contact the on-call paediatric infectious diseases service at the Royal Children's or Monash Children's hospitals.
Transfer to a tertiary centre may be required. Contact PIPER on 1300 137 650.
The syndrome is named:
• paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) in the UK
• multisystem inflammatory syndrome in children (MIS-C) in the US.
PIMS-TS has been described in children in areas with high incidence of acute SARS-CoV-2 infection. Case incidence has been noted to increase in the weeks after COVID-19 peaks.
There are likely to be further, albeit relatively rare, cases of PIMS-TS in Australia in areas with higher SARS-CoV-2 transmission.
PIMS-TS occurs two to six weeks after infection with SARS-CoV-2. The initial infection may be asymptomatic or mild in children and adolescents.
The median age is nine years, but it has been reported from infancy onwards and also in young adults.
PIMS-TS is more common in boys, those of race/ethnicity other than Anglo-European, and children with obesity.
Signs and symptoms
Severity of PIMS-TS varies. There are three overlapping clinical phenotypes:
- Shock-like presentation characterised by gastrointestinal symptoms (abdominal pain, diarrhoea, vomiting), distributive shock (due to myocardial dysfunction), polymorphous rash, headache and altered conscious state.
- Kawasaki disease-like phenotype (often fulfilling American Heart Association diagnostic criteria for complete or incomplete Kawasaki disease) that is commoner in those <5 years with fever, polymorphous non-blanching rash, mucosal involvement and non-purulent conjunctival injection. Cervical lymphadenopathy may occur and children may complain of a stiff, painful neck.
- Undefined inflammatory presentation with persistent fever and some signs of PIMS-TS, but without cardiac involvement or shock. May progress to more severe disease or resolve, even without treatment.
In more severe cases, myocardial dysfunction requiring ICU admission occurs in at least half the patients. Coronary artery aneurysms occur in approximately 15 per cent.
ECMO has been needed in some cases and occasional deaths have been reported overseas.
PIMS-TS case definition from the Paediatric Active Enhanced Disease Surveillance (PAEDS) network.
Children and adolescents (up to 18 years of age) with fever ≥3 days
AND two of the following:
- Rash or bilateral non-purulent conjunctivitis or muco-cutaneous inflammation signs (oral, hands or feet).
- Age specific hypotension or 'shock' within 24 hours of presentation.
- Features of myocardial dysfunction, pericarditis, valvulitis, or coronary abnormalities (including ECHO findings or elevated Troponin/NT-proBNP).
- Evidence of coagulopathy (by PT, PTT, elevated d-dimers).
- Acute gastrointestinal problems (diarrhoea, vomiting or abdominal pain).
AND Elevated markers of inflammation such as ESR, C-reactive protein, or procalcitonin.
AND Exclusion of other infectious causes of inflammation, including bacterial sepsis, staphylococcal or streptococcal toxic shock syndromes.
AND Evidence of current or recent SARS-CoV-2 infection (RT-PCR or serology), or confirmed contact with COVID-19 case. [Note testing may be delayed, particularly serology.]
Differential diagnoses include:
- staphylococcal and streptococcal toxic shock syndrome
- Kawasaki disease
- bacterial sepsis
Refer to statewide paediatric clinical guidelines for more information.
Dufort EM et al, N Engl J Med 2020, Multisystem Inflammatory Syndrome in Children in New York State
Goldfred-Cato S et al MMWR 2020, COVID-19–Associated Multisystem Inflammatory Syndrome in Children — United States, March–July 2020
Singh-Grewal D et al, J Paeds Child Health 2020, Update on the COVID‐19‐associated inflammatory syndrome in children and adolescents; paediatric inflammatory multisystem syndrome‐temporally associated with SARS‐CoV‐2