In December 2019, coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China [1]. This disease was caused by a new coronavirus, called Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) [2]. In contrast to past epidemics, which took years to spread around the world, the new virus reached Europe in a few months [3], with the first official case identified in Northern Italy on February 18 [4] and leading to the Italian outbreak. COVID-19 is a systemic disease [5], presenting with interstitial pneumonia (computed tomographic scan is the gold standard for diagnosis) [6–8], but it can also have a paucisymptomatic course [9]. The rate of newly infected patients increased daily on a logarithmic scale, especially in Lombardy, the most populated region in Italy (about 10 million inhabitants), forcing the Italian government to take extraordinary measures to contain the infection. Quarantine and the closure of non-essential activities were enforced.