Clinical assessment of asthma and COPD.

Asthma and COPD are 2 different chronic inflammatory respiratory disorders that may share one common functional abnormality, i.e. poorly reversible airflow limitation . According to definitions, airflow limitation in asthma is reversible or at least partly reversible either spontaneously or with treatment , whereas in COPD airflow limitation is usually poorly reversible or not reversible at all.In the pathogenesis of both asthma and COPD, individual genetic susceptibility and environmental exposures are relevant for disease expression. Cigarette smoking is the major cause of COPD; the causes of asthma remain largely uncertain, even if atopy and allergen exposure have certainly a major role asthma is in fact a phenotypically heterogeneous disorder and, over the years, many different clinical subtypes of asthma have been described; in particular asthma starting in adulthood, noneosinophilic asthma, and asthma in obese subjects constitute an important part of the adult asthma population, and are still poorly characterize. The differential diagnosis between asthma and COPD is quite simple when considering the typical clinical and functional features of these 2 diseases. In this context, it is easy to recognise asthma in a young, atopic, non smoking subject with recurrent dyspnoea, wheezing or chest tightness, and variable reversible airflow limitation. It is also easy to diagnose COPD in a subject older than 40, smoker, presenting with dyspnoea, chronic cough, sputum and fixed airflow limitation and no history of asthma or allergic diseases. The difficulty comes when trying to make a diagnosis of asthma and/or COPD in a middle age or elderly patient, smoker, maybe atopic and/or with a history of asthma, complaining chronic dyspnoea but not wheezing, nor chronic cough and sputum, and presenting with poorly reversible airflow limitation. The difficulty comes also when trying to make a confirm diagnosis of asthma or establish a diagnosis of COPD in a middle age or elderly patient, with a clear history of atopy and asthma, bronchodilator reversibility, recurrent wheezing, but who also smokes and have chronic cough and sputum, and dyspnea, that are nor suppressed by inhaled steorids. In these “borderline” patients, differential diagnosis might become important from a clinical and therapeutic point of view. In fact, inhaled glucocorticosteroids are the first choice regular medication in asthma but not in COPD, whereas regular bronchodilators are the first choice regular medication in COPD but not in asthma, and thus the differential diagnosis between asthma and COPD is important to decide whether or not prescribing regular treatment with steroids or bronchodilators in patients with overlapping features.