Clinical Presentation
Asthma is characterized by a history of respiratory symptoms (eg wheeze, shortness of breath, chest tightness, cough) that vary over time and in intensity, together with variable expiratory airflow limitation. Symptoms occur with exercise, laughing, or crying in the absence of an apparent respiratory infection.
Symptoms (Recurrent Episodes)
Symptoms of recurrent episodes include wheezing, breathlessness, heavy breathing, chest tightness, reduced activity, and recurrent or persistent non-productive cough that may be worse at night.
History
Identify the symptoms likely due to asthma. Determine the symptom pattern for the past 3-4 months. Focus on symptoms that occurred in the past 2 weeks. History of variability is essential in the diagnosis of asthma; variability refers to improvement or worsening of symptoms and lung function occurring over a period of time (eg day to day, month to month, or seasonally).
Key Indicators for Considering a Diagnosis of Asthma
Asthma may be considered by episodes of wheezing occurring >1x/month or symptoms occurring >3 episodes/year. Wheezing occurring during sleep, activity, laughing, or crying, with increasing recurrence, is likely due to asthma. Activity-induced coughs, usually accompanied by wheezing or heavy breathing, may also indicate asthma. The cough should be non-productive and recurrent or persistent, particularly when occurring at night or when accompanied by wheezing in the absence of viral infection. Heavy breathing, shortness of breath, or difficulty breathing during exercise or activity that is noticeably recurrent increases the likelihood of asthma. Other indicators include persistence of asthma symptoms beyond age 3 years; symptoms triggered or exacerbated by animal fur, aerosol, temperature changes, dust mites, drugs, etc.; symptoms (eg cough, wheeze, heavy breathing) lasting longer than 10 days in the presence of an upper respiratory tract infection (URTI); symptoms that improve with asthma medication; and the presence of a patient or family history of allergic disease (eg atopic dermatitis, allergic rhinitis).
Physical Examination
Perform a thorough exam with a focus on observation of forced expiration and nasal inspection. Note for hyperexpansion of the thorax, wheezing during normal breathing or prolonged forced exhalation, increased nasal secretion, mucosal swelling or nasal polyps, and signs of allergic skin condition. Occasionally, wheezing may not be seen in severe asthma attacks due to markedly reduced airflow and ventilation. Other signs may also be present (eg cyanosis, drowsiness, tachycardia, difficulty speaking).