Which of the following indicates asthma: polyphonic wheezing with exercise, normal X-ray (radiograph) between episodes, or a family history (family medical history) of asthma?

Which Features Indicate Asthma?

Polyphonic wheezing with exercise is the strongest indicator of asthma among these three options, as it represents a cardinal clinical sign demonstrating the hallmark pathophysiology of exercise-triggered, reversible airway obstruction.

Diagnostic Value of Each Feature

A. Polyphonic Wheezing with Exercise - MOST INDICATIVE

Polyphonic wheeze (diffuse, bilateral, particularly expiratory) is explicitly described as a cardinal sign of asthma that should be documented in clinical notes. 1 The British Thoracic Society guidelines emphasize that exercise-provoked symptoms are a defining hallmark of asthma, distinguishing it from other respiratory conditions. 1

The combination of polyphonic wheeze triggered specifically by exercise demonstrates two critical diagnostic features simultaneously:

• The characteristic polyphonic quality indicates diffuse airway involvement rather than localized obstruction 1
• Exercise as a trigger confirms the variable, provoked nature of airway hyperresponsiveness that defines asthma 2, 3

Exercise-induced bronchospasm demonstrates reversible airway hyperresponsiveness, the key pathophysiologic feature of asthma. 3 This makes exercise-triggered wheezing highly characteristic and diagnostically valuable. 2, 4, 5

B. Normal X-ray Between Episodes - EXPECTED BUT NOT DIAGNOSTIC

Chest X-rays are typically normal in asthma between exacerbations, but this finding does not increase or decrease the likelihood of asthma diagnosis. 3 The British Thoracic Society explicitly states that "outside acute episodes, there may be no objective signs of asthma." 1

A normal chest X-ray between episodes:

• Is consistent with asthma but also seen in many other intermittent respiratory conditions 2
• Does not confirm or exclude asthma - the diagnosis is clinical, not radiographic 1, 2
• Lacks specificity - many conditions present with normal imaging between symptomatic periods 2

C. Family History of Asthma - CONTRIBUTORY BUT NOT DIAGNOSTIC

Family history is considered "additional information which may contribute towards a clinical suspicion" rather than a diagnostic criterion. 1 While family history of asthma or atopic conditions is the most important risk factor for developing atopy, it does not confirm the diagnosis. 3

The British Thoracic Society categorizes personal or family history of asthma under "Additional Information" that supports clinical suspicion, not under primary diagnostic signs or symptoms. 1

Clinical Algorithm for Interpretation

When evaluating these features:

1. Polyphonic wheezing provoked by exercise → Strongly suggests asthma; proceed with objective testing (spirometry, peak flow variability) 1

2. Normal X-ray between episodes → Neither confirms nor excludes asthma; focus on clinical symptoms and objective airflow testing 1, 2, 3

3. Family history alone → Increases suspicion but requires documentation of characteristic symptoms (variable, intermittent, triggered) and objective airflow limitation 1, 3

Critical Pitfall to Avoid

Do not diagnose asthma based solely on family history or normal imaging. The European Respiratory Society explicitly warns that symptoms alone result in misdiagnosis in a considerable number of patients, and diagnosis should not be based on family history without documenting variable airflow obstruction or characteristic symptom patterns like exercise-induced bronchospasm. 3