## 3 Results of the Survey  
### The \"COVID-19 Path\" for Asthma Patients in the ED  
The COVID-19 pandemic continues to heavily affect the EDs around the world. In particular, a complete reorganization of the access routes was necessary. First, it is essential to correctly designate incoming patient flows to immediately separate those who are potentially infected from those who probably are not. Patients reporting respiratory symptoms (regardless of the presence of fever) and/or changes in taste and/or smell should flow directly to the \"COVID-19 area\". In case of fever associated with clinical symptoms or signs of clear other non-respiratory origin, patients should flow into the \"no COVID-19 area\". In this case, performing a point-of-care antigenic swab, if available, could be helpful, as a negative result significantly decreases the possibility of misdiagnosis of SARS-CoV-2 infection [15]. Because of the presence of dyspnea, which is also a common presentation of COVID-19 [2], all patients with a history or suspicion of asthma should initially flow into the COVID-19 path. After a rapid assessment of symptoms and temperature/vital parameters, management of patients with a suspected exacerbation of asthma should initially take place in the isolation area, and they should undergo molecular-based testing for the diagnosis of SARS-CoV-2 infection [16]. After the first medical examination, all such patients should undergo urgent chest radiography. Although not recommended per se in the entire asthmatic population attending the ED [2; 17], this examination is useful for rapid screening for the presence of lung infiltrates suggestive of SARS-CoV-2 infection. Non-contrast high-resolution computed tomography (HRCT) shows high accuracy for COVID-19 pneumonia, sometimes preceding the positivity of molecular-based testing for SARS-CoV-2 [18; 19]. However, some problems limit the use of HRCT for large-scale screening of COVID-19: its limited availability in many ED and the prolonged waiting times due to the transfer of potentially infected patients and the subsequent need for decontamination. For these reasons, in the ED setting, a dedicated portable chest radiograph can play an important role in the initial screening and diagnosis of COVID-19 [20]. It provides, in fact, lower sensitivity but similar specificity than that provided by the HRCT, for the diagnosis of COVID-19 [21]. Lung ultrasonography showed good sensitivity (similar to that of HRCT) but it is not specific for the diagnosis of COVID-19 (inferior to both HRCT and radiography) [22]. Lung ultrasound requires adequate expertise, but the learning curve is rather short. On the other hand, it involves closer proximity of the operator to the patient for a longer period, thus requiring specific infection prevention and control precautions. It is an alternative modality particularly useful in specific adult subgroups, for example, pregnant women [21].  
After a complete clinical examination in the ED, all patients who receive a diagnosis of asthma exacerbation or a new diagnosis of asthma, who have both a negative radiological and nasopharyngeal swab for SARS-CoV-2 and who require further observation or hospitalization can be transferred to the no-COVID-19 area. Patients with a questionable clinical picture for COVID-19, and who cannot be discharged, should remain in the isolation area and repeat the nasopharyngeal swab 24 h after. In case of further negativity, they can switch to the \"clean\" path.  
For more details on our proposal of a rational \"COVID-19 path\" in the ED, please refer to Figure 1.