What are the recommended diagnosis and treatment approaches for asthma?

Asthma Diagnosis and Treatment

The recommended approach for asthma management involves classifying severity at initial diagnosis, implementing a stepwise treatment approach with inhaled corticosteroids as the cornerstone therapy for persistent asthma, and regularly monitoring control to adjust therapy accordingly. 1, 2

Diagnosis of Asthma

Key Diagnostic Criteria

• Symptoms suggestive of asthma:
  • Recurrent episodes of wheezing, cough (particularly at night), chest tightness, and shortness of breath
  • Symptoms that worsen with triggers: exercise, viral infections, allergens, irritants, weather changes, stress
  • Symptoms that improve with bronchodilator therapy
  • Symptoms that worsen at night, awakening the patient 1

Objective Testing

• Spirometry: Essential for confirming diagnosis

  • Demonstration of airflow obstruction: FEV1/FVC reduced
  • Reversibility: Increase in FEV1 of >200 mL and ≥12% from baseline after bronchodilator administration 1
  • Should be performed at initial assessment and periodically to monitor disease progression 3

• Peak Expiratory Flow (PEF) monitoring:

  • Variability ≥20% establishes diagnosis of asthma
  • Useful for ongoing monitoring, especially in moderate to severe cases 4

Classification of Asthma Severity

Asthma severity should be classified before initiating therapy based on both impairment and risk domains:

Impairment Domain

• Frequency and intensity of symptoms
• Nighttime awakenings
• Use of rescue medications
• Activity limitations
• Lung function measurements

Risk Domain

• Frequency of exacerbations requiring oral corticosteroids
• Risk of progressive lung function decline 1, 2

Severity Categories

1. Intermittent: Symptoms ≤2 days/week, nighttime awakenings ≤2x/month, FEV1 >80% predicted
2. Mild Persistent: Symptoms >2 days/week but not daily, nighttime awakenings 3-4x/month, FEV1 ≥80% predicted
3. Moderate Persistent: Daily symptoms, nighttime awakenings >1x/week, FEV1 60-80% predicted
4. Severe Persistent: Continuous symptoms, frequent nighttime awakenings, FEV1 <60% predicted 1

Treatment Approach

Stepwise Approach to Therapy

Treatment follows a stepwise approach based on severity at diagnosis and level of control during follow-up:

Step 1 (Intermittent Asthma)

• SABA as needed for symptom relief
• No daily controller medication needed 1, 2

Step 2 (Mild Persistent Asthma)

• Preferred: Low-dose inhaled corticosteroid (ICS) daily
• Alternative: Leukotriene receptor antagonist, cromolyn, or nedocromil 1, 2

Step 3 (Moderate Persistent Asthma)

• Preferred: Low-dose ICS plus long-acting beta-agonist (LABA) OR medium-dose ICS
• Alternative: Low-dose ICS plus either leukotriene modifier, theophylline, or zileuton 1, 2

Step 4 (Moderate-to-Severe Persistent Asthma)

• Preferred: Medium-dose ICS plus LABA
• Alternative: Medium-dose ICS plus either leukotriene modifier, theophylline, or zileuton 1

Step 5-6 (Severe Persistent Asthma)

• Preferred: High-dose ICS plus LABA, with consideration of omalizumab for allergic asthma
• Add oral corticosteroids if necessary 1

Quick-Relief Medications

• Short-acting beta-agonists (SABAs) as needed for all patients
• Use of SABA >2 days/week (except for exercise prevention) indicates inadequate control 1

Monitoring and Follow-up

Regular Assessment of Control

• Schedule visits every 2-6 weeks when initiating therapy or stepping up treatment
• Once control is achieved, follow-up every 1-6 months depending on severity
• Consider visits every 3 months if step-down in therapy is anticipated 1

Objective Monitoring

• Perform spirometry:
  • At initial assessment
  • After treatment is initiated and symptoms stabilize
  • During periods of worsening control
  • At least every 1-2 years 1

Criteria for Well-Controlled Asthma

• Symptoms ≤2 days/week
• Nighttime awakenings ≤2x/month
• No interference with normal activity
• SABA use ≤2 days/week
• FEV1 or PEF ≥80% predicted/personal best 1

Special Considerations

Exercise-Induced Bronchoconstriction

• Prevent with appropriate long-term control therapy
• Pre-treatment with SABA, leukotriene modifiers, or cromolyn before exercise 1

Comorbid Conditions

• Evaluate and treat conditions that can worsen asthma:
  • Allergic rhinitis
  • Sinusitis
  • Gastroesophageal reflux disease
  • Obesity 1, 5

Referral to Specialist

Refer to an asthma specialist if:

• Patient required >2 bursts of oral corticosteroids in 1 year
• Exacerbation requiring hospitalization
• Step 4 care or higher is required (Step 3 or higher for children 0-4 years)
• Immunotherapy or omalizumab is being considered
• Additional testing is indicated 1

Common Pitfalls to Avoid

• Underestimating severity of exacerbations
• Delaying corticosteroid administration during exacerbations
• Inappropriate discharge without meeting all criteria for stability
• Failing to address environmental triggers and comorbidities
• Not providing a written asthma action plan 2
• Overreliance on bronchodilators without addressing underlying inflammation 6

By following this structured approach to diagnosis and management, clinicians can effectively control asthma symptoms, reduce exacerbation risk, and improve patients' quality of life.