Defining the scourge of COVID-19 hyperinflammatory syndrome

It is abundantly clear that a subset of patients admitted to hospital with COVID-19 develop hyperinflammatory complications of severe COVID-19 infection or cytokine storm syndrome,1, 2 which is frequently fatal. What is less clear is how to define the cytokine storm syndrome in the context of severe COVID-19 infection. In The Lancet Rheumatology, Webb and colleagues3 propose a set of clinical criteria for COVID-19-associated hyperinflammatory syndrome (cHIS). Development of such criteria are critically important for clinical trial enrolment and for aiding clinicians in recognising patients who will benefit from therapy targeting the cytokine storm syndrome associated with COVID-19.