Multi-System Inflammatory Syndrome Associated with COVID-19
Paediatric Multisystem Inflammatory Syndrome Temporally Associated with COVID-19 (PIMS-TS)
COVID-19 infection in children generally produces mild symptoms. Indeed the mortality rate in the under 9 years of age group quoted by doctors in the Wuhan region of China who first published significant data on COVID-19, was essentially zero. However, over the past few months a small number of children have been identified who develop a significant systemic inflammatory response. As of the 15th May the total number across Europe stood at 230 suspected cases including 2 fatalities, one in the UK and one in France.
This syndrome shares features with other paediatric inflammatory conditions including Kawasaki disease, staphylococcal and streptococcal toxic shock syndrome, bacterial sepsis and macrophage activation syndromes. It can also present with unusual abdominal symptoms.
The first case of Kawasaki disease with concurrent COVID-19 was published in the US on the 7th April 2020. This was in a 6 month infant with persistent fever.
In the UK the Paediatric Intensive Care Society (PICS) published a statement on the 27th April after an alert from NHS England highlighting a spike in numbers of critically ill children presenting with unusual symptoms. This was followed by the RCPCH publishing guidance on the 1st May 2020. The RCPCH has subsequently launched a surveillance study to monitor the progress of this disease (via the BPSU).
Clinical features of PIMS-TS include persistent fever, inflammation (neutrophilia, elevated CRP and lymphopaenia) and evidence of single or multi-organ dysfunction (shock, cardiac, respiratory, renal, gastrointestinal or neurological disorder) with other additional clinical, laboratory or imagining and ECG features. Children fulfilling full or partial criteria for Kawasaki disease may also be included. The confirmation of COVID-19 infection by RT-PCR is not a pre-requisite in diagnosing this condition based on RCPCH guidelines published on the 1st May 2020. Other diagnoses such as sepsis, toxic shock syndrome and enterovirus infection should be excluded and treated appropriately.
Unpublished data suggests that there are a further 300 possible cases in the US and Europe that are undergoing further investigation. Co-infection with other pathogens has been investigated and in a few cases human metapneumovirus has been detected.