confluent rash on the patient's trunk and on the flexor surfaces of his arms and legs (Fig. 1a,b). Petechiae were not apparent. He had neither itching nor pain, and no systemic lymphadenopathy was observed. A drug allergy was not suspected based on his recent medication history, and measles and rubella were ruled out by antibody tests. Laboratory data revealed a white blood cell count of 2.8 9 10 3 /L, hemoglobin level of 15.5 g/dL and platelet count of 153 9 10 3 /µL, which was less than half of his baseline platelet count. Although the rash appeared to be similar to that developed under dengue fever, his dengue virus NS1 antigen test was negative. On admission, the patient did not complain of respiratory symptoms but had mild hypoxemia, for which he underwent chest computed tomography. Imaging results suggested COVID-19,