Isolated Sudden Onset Anosmia in COVID-19 Infection. A Novel Syndrome?

BACKGROUND: The amelioration of the current COVID pandemic relies on swift and efficient case finding as well as stringent social distancing measures. Current advice suggests that fever or new onset dry cough are the commonest presenting complaints. METHODOLOGY: We present a case report and case series as well as other evidence that there is an important fourth presenting syndrome, namely isolated sudden onset anosmia (ISOA), which should be considered highly suspicious for SARS-CoV-2. RESULTS: A patient presenting with ISOA who went on to test positive for infection with COVID-19 and did not develop any further symptoms as well as a case series of similar patients although limited by the lack of reliable testing at the moment. CONCLUSIONS: We posit the existence of a fourth common syndrome of COVID-19 infection: isolated sudden onset anosmia (ISOA) and urge the international community to consider this presentation in current management advice.