Accurate Asthma Diagnosis
Symptoms of intermittent dyspnea, wheezing, and cough are classically associated with asthma, but these are nonspecific and presentation with atypical asthma symptoms such as cough is common. Therefore, asthma should be considered whether classical symptoms are present or not, and evaluation for other nonasthma diagnoses is warranted,
even when patients present with classical symptoms. Although the diagnosis of asthma is based on clinical findings, objective measurements, such as reversible airflow obstruction, can be used to support a diagnosis. Guidelines for the diagnosis of asthma have been published by several organizations for both children and adults.9,10
These guidelines emphasize the need for a careful history, including identifying common triggers, work exposures, personal history of wheezing, symptoms with exercise, and family history of asthma symptoms. Evaluation in patients > 5 years of age should include spirometry with evaluation for a bronchodilator response and in patients without airflow obstruction consideration of bronchoprovocation testing.
Further testing may include measurement of exhaled fractional excretion of nitric oxide, CBC count with differential to evaluate for eosinophilia, serum IgE levels, and allergy testing. In cases of persistent or severe asthma, all of these tests and imaging
chest radiograph and/or chest CT scan) and alpha-1 antitrypsin level and phenotype are indicated. Figure 1 provides a step-by-step approach to evaluation, diagnostic testing, and interventions when severe asthma is considered.
