The diagnosis of asthma in older patients

Half of the elderly persons with asthma have not been diagnosed, yet their quality of life is substantially lower than others their age. Primary care physicians should, therefore, be encouraged to ask about respiratory symptoms in elderly patients and then perform office spirometry for those with symptoms. Airway obstruction then increases the likelihood of asthma, but the lack of a "significant" acute bronchodilator response is clinically meaningless. Methacholine challenge testing is safe and useful for detecting asthma in patients with normal baseline spirometry. When spirometry shows airway obstruction post-bronchodilator, a normal diffusing capacity (DLCO) test will rule out COPD in current and former smokers. A normal chest X-ray and B-type natriuretic peptide (BNP) will rule out congestive heart failure (CHF) in those with dyspnea.