ABSTRACT
Diagnosis Asthma is characterized by reversible episodic symptoms of airway obstruction, in which alternative explanations have been excluded. For example, typical symptoms and a large reversibility (usually with betamimetic nebulizer treatment) of airflow obstruction on spirometry (increase in FEV1 >15%) generally confirm the diagnosis of asthma. Airway inflammation with edema and remodeling rather than simply bronchospasm is the key. Increased airway responsiveness to stimuli is characteristic. Indicators that suggest a diagnosis of asthma include wheezing; history of recurrent cough; chest tightness or difficulty in breathing; worsening of symptoms with exercise; viral infection; exposure to animal fur or feathers, mold, pollen, house dust mites, tobacco or wood smoke;
changes in weather; airborne chemicals or dusts; or worsening of symptoms at night. Physical examination is not always reliable and may include thoracic hyperexpansion or chest deformity, hunching of shoulders or use of accessory muscles, audible wheezing or a prolonged expiratory phase, increased nasal discharge or nasal polyps, or any manifestation of an allergic skin condition. The more indicators present, the more likely the diagnosis; however, the absence of wheezing does not equal the absence of asthma. A clinical diagnosis of asthma can be confirmed with the use of spirometry, which can be used to determine whether airflow obstruction is present and, if so, whether it is reversible. Additionally, forced vital capacity (FVC), FEV1, and FEV1/FVC ratio are measured before and after administration of a short-acting bronchodilator. Reduced FEV1 or FEV1/FVC shows airflow limitation, and a 12% or greater improvement in FEV1 after the administration of inhaled albuterol confirms reversibility [1].
