Extra-respiratory manifestations of COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global health threat. Although most patients with COVID-19 manifest fever and respiratory tract symptoms, SARS-CoV-2 infection may also involve other organs/systems and present with extra-respiratory manifestations, including cardiac, gastrointestinal, hepatic, renal, neurological, olfactory, gustatory, ocular, cutaneous and haematological symptoms. Occasionally, these extra-respiratory symptoms/signs represent the initial presentation of SARS-CoV-2 infection, prior to fever or respiratory manifestations. Therefore, this comprehensive review of the extra-respiratory manifestations of COVID-19 is intended to help clinicians better understand the range of clinical presentations associated with SARS-CoV-2 infection, allowing the consideration of COVID-19 in differential diagnoses. A screening test for SARS-CoV-2 should be performed when patients have these extra-respiratory manifestations. In addition, clinicians should be alerted to the adverse effects of anti-SARS-CoV-2 agents that can mimic the extra-respiratory manifestations of COVID-19. Moreover, some extra-respiratory manifestations, such as ocular and gastrointestinal involvement, may be caused by direct invasion of SARS-CoV-2. Therefore, protective measures should be taken while managing the associated clinical specimens. Finally, several extra-respiratory manifestations, such as cardiac involvement, acute kidney injury, coagulation disorders and thrombotic complications, could be associated with a poor prognosis.