Diagnosis of asthma and copd

The differential diagnosis between asthma and COPD is quite simple when the typical clinical and functional features of either disease are present. The difficulty comes when trying to make a diagnosis of asthma or COPD in a middle-aged or elderly patient, a smoker, who may be atopic or have a history of asthma, who complains of chronic dyspnea but not wheezing, chronic cough, or sputum, and who presents with poorly reversible airflow limitation. It is also difficult to make a diagnosis of asthma or COPD in a middle-aged or elderly patient who has a clear history of atopy and asthma, bronchodilator reversibility, and recurrent wheezing, but who also smokes and has chronic cough and sputum and dyspnea that are not suppressed by inhaled steroids. The diagnosis of asthma or COPD is based on clinical history and lung function tests, particularly peak expiratory flow (PEF) and spirometry, with assessment of spontaneous or postbronchodilator reversibility of airflow limitation. Allergy tests are also usually performed for the diagnosis of asthma, but not of COPD patients, to identify allergens responsible for asthma exacerbations and to consider the opportunity to treat the patient with immunotherapy. While the diagnosis and assessment of severity of asthma and COPD can be fully established on the basis of clinical history and lung function tests, additional tests might be helpful to better characterize individual patients.