Functional Examination of the Upper and Lower Airways in Asthma and Respiratory Allergic Diseases: Considerations in the Post–SARS-CoV-2 Era

Airway examination techniques are procedures that can potentially transmit infectious diseases to both patients and healthcare professionals who perform them, by various mechanisms. The pandemic situation due to the COVID-19 disease has practically halted most of the activity of the clinics and laboratories of pulmonary and nasal function, with clear recommendations in this regard. Being already in the early stages after the peak of the pandemic, we still do not know for sure what its consequences will be in the short or long term, since there are important gaps in the knowledge of aspects as fundamental as the transmission mechanisms of the virus, its pathophysiology and immune response or its diagnosis. In this review we will examine the different examination techniques available on the assessment of patients suffering from respiratory allergy, asthma and associated diseases, int the postpandemic momentum, highlighting their possible advantages and disadvantages. For this reason, we wanted to focus on exploring the entire upper and lower airways, from the perspective of the safety of both the healthcare professionals and patients and their specific characteristics. And at the same time we will approach the analysis of the intrinsic value that these interventions provide from the point of view of both diagnosis and management of these patients. The changing situation of this disease may cause some modifications of the assertions presented in this review in the future.While this guidance seeks to ensure a consistent wide approach, some differences in operational details may be applied due to local regulations.