## 3 Results of the Survey
### Management of Adult Patients with Asthma in the ED at the Time of COVID-19 Pandemic
#### 3.2.2 Asthma and COVID-19: What We Know Today  
According to current literature data, patients with asthma have a reduced or at least not increased risk of SARS-CoV-2 infection [32; 33]. Since the angiotensin-converting enzyme 2 (ACE-2) receptor is the well-known gateway for virus entry into the human body, the downregulation of its expression observed in asthmatics may help explain the reduced susceptibility of these patients to SARS-CoV-2 infection [13; 34; 35]. The reduced expression of ACE-2 receptors seems to be the effect of IL-13 activity produced by eosinophil cells [33; 34]. In addition, patients with asthma have a similar risk of hospitalization, complications and death compared with the general population [13; 24; 35; 36; 37; 38; 39]. Probably the imbalance toward the T2-type immune response, observed in this population, counteracts the typical T1-type response in COVID-19, reducing the risk of complications due to proinflammatory T11-cytokines, such as IL-6, among others [33; 40; 41; 42; 43; 44; 45]. [PERSON] et al. [46] showed a potential protective role of eosinophil in asthmatic patients with COVID-19. Specifically, in symptomatic asthmatics with COVID-19 infection, the Th2-asthma phenotype characterized by eosinophil in peripheral blood (150 cells/mL) was associated with reduced hospitalization. The initial concern that patients chronically receiving inhaled or oral corticosteroids or biologic drugs could be at risk of worse outcome in the case of SARS-CoV-2 infection has not been confirmed by the literature data available to date [47; 48; 49; 50]. Interestingly, in outpatients with SARS-CoV-2 infection and mild symptoms, inhaled corticosteroids seem to reduce the combined endpoint represented by admission to hospital or death to increase the resolution of symptoms at two weeks [51]. Results from the literature support the benefit of systemic corticosteroids in the treatment of severe asthma and asthma exacerbations [52; 53; 54]. The RECOVERY trial [52], by far the largest randomized controlled study examining the role of corticosteroids in COVID-19 disease, showed a clear benefit in 28-day mortality with the use of dexamethasone at the dosage of 6 mg/day for 10 days in COVID-19 patients on oxygen supplementation or invasive mechanical ventilation. This benefit was absent in the group not requiring oxygen supplementation, in which a slight increase in mortality was observed but did not reach statistical significance. Based on the evidence available to date [3; 22; 47; 55; 56], we suggest that asthmatic patients should continue their prescribed asthma therapy, even when it includes oral or inhaled corticosteroids and/or biological drugs (e.g., omalizumab, mepolizumab, reslizumab, benzlizumab, dupilumab, etc.) Physicians could evaluate, case by case, a modification of their therapy if SARS-CoV-2 infection arises. Similarly, given the literature data, in the presence of asthma and COVID-19 without the need for oxygen supplementation, if there is an indication for corticosteroid use based on the presence of severe asthma or exacerbation of asthma, we recommend starting treatment. 2.3 Medical Treatment of Severe Asthma Exacerbations in the COVID-19 Era in the Emergency Department  
In the absence of data from targeted studies, the overall treatment of severe asthma exacerbations should not change substantially at the time or in the presence of SARS-CoV-2 infection [3; 23; 57]. The recurring warning to emergency physicians is to limit aerosol treatments to reduce the virus spread to patients who, due to common overcrowding of ED, are often too many compared to the available space. Some authors emphasized that a pressurized metered dose inhaler (MDI) via a spacer should be preferred to nebulizers (except for life-threatening exacerbations) to minimize aerosol and droplet generation [23]. In addition, a mouthpiece or mask can be added to the spacer if the patients need it [3; 31; 48; 53; 57].