What are the classic symptoms of asthma and how are they managed?

Classic Symptoms of Asthma

The classic symptoms of asthma include wheeze, shortness of breath, chest tightness, and cough, which typically present in a variable, intermittent pattern that worsens at night and is provoked by specific triggers including exercise. 1

Key Symptoms and Characteristics

Asthma symptoms have several distinctive features that help distinguish them from other respiratory conditions:

• Core symptoms:

  • Wheeze (usually diffuse, polyphonic, bilateral and particularly expiratory)
  • Shortness of breath (dyspnea)
  • Chest tightness
  • Cough (may be the predominant symptom in cough variant asthma) 1

• Characteristic patterns:

  • Variable intensity
  • Intermittent presentation
  • Nocturnal worsening
  • Provoked by specific triggers 1

Triggers and Exacerbating Factors

Symptoms often worsen after exposure to:

• Exercise
• Allergens (pollens, dust, feathered or furry animals)
• Viral respiratory infections
• Environmental chemicals and irritants
• Tobacco smoke
• Aspirin/NSAIDs
• Beta-blockers 1

Signs During Exacerbations

During asthma exacerbations, patients typically present with:

• Wheezing (a cardinal sign)
• Reduced lung function (decreased peak flow or obstructive pattern on spirometry)
• Increased respiratory rate
• Increased pulse rate
• Use of accessory muscles
• Difficulty speaking in sentences or phrases (in more severe cases) 1

It's important to note that between acute episodes, patients may have no objective signs of asthma, making objective testing crucial for diagnosis 1.

Objective Testing

Asthma diagnosis should be corroborated by:

• Measurement of airflow limitation through PEF (peak expiratory flow) and FEV1 (forced expiratory volume in one second)
• Documentation of variability in lung function (either spontaneously over time or in response to therapy)
• A 20% or greater variability in PEF with a minimum change of at least 60 L/min is highly suggestive of asthma 1

Severity Classification

Asthma exacerbations are classified as:

• Mild
• Moderate
• Severe
• Life-threatening

The primary determinant of severity is the percent predicted FEV1 or PEF, which guides treatment decisions 1.

Common Pitfalls in Diagnosis

1. Misdiagnosis: None of the asthma symptoms are specific to the condition alone, requiring careful differentiation from other respiratory disorders 1.

2. Overlooking cough variant asthma: When cough is the predominant symptom without wheeze, asthma may be missed 1.

3. Missing asthma between episodes: Outside acute episodes, there may be no objective signs, leading to diagnostic uncertainty 1.

4. Failing to document variability: Repeated normal lung function tests in the presence of symptoms should raise doubt about an asthma diagnosis 1.

5. Not recognizing risk factors for severe exacerbations: Patients with previous severe exacerbations, frequent healthcare utilization, or high SABA use are at increased risk of life-threatening episodes 1.

By recognizing these classic symptoms and their patterns, clinicians can more effectively diagnose asthma and distinguish it from other respiratory conditions that may present with similar features.