PIM-TS stands for Paediatric  Multisystem Inflammatory Syndrome – Temporally Associated with SARS-CoV-2. It is the current name given to the hyperinflammatory state seen in children with exposure to SARS-CoV-2. 

There are many similarities between the clinical presentation of PIM-TS and Kawasaki Disease, in particular, the unrelenting fever, rash, conjunctivitis and peripheral oedema. Vascular involvement has also been demonstrated with echo-bright coronary arteries in all children, and a giant coronary artery aneurysm in one child.

The rash has been described in varying ways

1. A polymorphic rash, changes of the lips or oral cavity, laterocervical lymphadenopathy, diarrhoea (Italy)

2. Persistent erythematous, seemingly non- pruritic, blotchy rash(US)

A case definition was rapidly produced by the RCPCH and is helpful to define PIM-TS further:

A child presenting with persistent fever, inflammation (neutrophilia, elevated CRP, and lymphopaenia) with evidence of single or multi-organ dysfunction (shock, cardiac, respiratory, renal, gastrointestinal, or neurological disorder) with additional features. This may include children fulfilling full or partial criteria for Kawasaki Disease

Exclusion of any other microbial cause, including bacterial sepsis, staphylococcal or streptococcal shock syndromes, infections associated with myocarditis such as enterovirus

SARS-CoV-2 PCR testing may be positive or negative

There are some particularly notable features of PIMS-TS including abdominal pain and gastrointestinal symptoms that are predominantly early symptoms. They are less commonly seen in Kawasaki Disease

Regarding management ,at this stage, we have more questions than answers about both the short and long term management of PIMS-TS. The RCPCH guidelines provide extensive advice on the suggested early medical management and investigations, coupled with ongoing monitoring and treatment. Importantly, robust discussion with a tertiary centre that includes paediatric infectious diseases, cardiology and rheumatology, must be part of the child’s management. 

All children described in the Riphagen study were treated with intravenous immunoglobulin (IVIG) and most were treated with aspirin, as a child with Kawasaki disease would be. In addition, all children received broad-spectrum antibiotics. The role of other immunomodulatory therapy is uncertain at this time.

For the emergency or general paediatrician, normal supportive measures for critically ill children should be instigated with early involvement of specialist teams. The RCPCH guidelines also suggest taking additional blood when gaining venous access for research purposes.