What is the recommended initial evaluation and treatment approach for an adult or child with suspected asthma and no significant medical history?

Diagnosis and Treatment of Asthma

Initial Diagnostic Evaluation

For children aged 5-16 years with suspected asthma, diagnose only when at least two objective tests are abnormal: spirometry, bronchodilator response (BDR), and/or FeNO measurement. 1

Essential Diagnostic Tests (Children 5-16 years)

• Spirometry: Perform as first-line test; consider FEV1/FVC <LLN or <80%, or FEV1 <LLN or <80% predicted as supportive of asthma 1

  • Normal spirometry does NOT exclude asthma, as it is frequently normal during stable disease 1

• Bronchodilator Response Testing: Perform in all children with abnormal spirometry (FEV1 <LLN or <80% predicted and/or FEV1/FVC <LLN or <80%) 1

  • Consider ≥12% and ≥200 mL increase in FEV1 following 400 μg SABA as diagnostic 1, 2
  • BDR <12% does NOT exclude asthma 1

• FeNO Measurement: Perform as part of diagnostic work-up 1

  • FeNO ≥25 ppb in symptomatic children supports asthma diagnosis 1
  • FeNO <25 ppb does NOT exclude asthma 1

Diagnostic Approach for Adults

• Confirm with spirometry demonstrating variable airflow obstruction through bronchodilator reversibility: improvement of ≥12% AND ≥200 mL in FEV1 2, 3
• Peak expiratory flow (PEF) measurements establish baseline values and evaluate daily variability; >20% variability suggests asthma 2
• Document key symptoms: frequency of daytime symptoms, nighttime awakenings, activity limitation, and rescue medication use 2, 4

When Diagnosis Remains Uncertain

• Methacholine challenge test: Use when asthma cannot be confirmed with first-line tests; PC20 ≤8 mg/mL is positive 1
• Trial of ICS therapy: Consider ONLY in symptomatic children with abnormal spirometry and negative BDR 1
  • Repeat objective tests (spirometry, FeNO) after 4-8 weeks 1
  • Do NOT diagnose based on symptom improvement alone; require objective improvement in lung function 1

Tests NOT Recommended for Diagnosis

• Allergy testing (skin-prick tests or serum IgE): Do NOT use as diagnostic tests for asthma 1
  • However, perform allergy testing in patients with persistent asthma requiring daily medications to identify triggers 2
• PEFR variability: Do NOT use as primary objective test alone 1

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Initial Treatment Approach

For mild persistent asthma in adults and children ≥12 years, use either daily low-dose ICS with as-needed SABA OR as-needed ICS-formoterol combination (not SABA monotherapy). 1, 2

Treatment by Severity Classification

Mild Persistent Asthma

• Preferred: Daily low-dose ICS with as-needed SABA for quick relief 1, 2
• Alternative (≥12 years): As-needed low-dose ICS-formoterol combination 1, 2
• Low-dose ICS improves control more effectively than any other single long-term controller 2

Moderate Persistent Asthma

• Preferred: Low-to-medium dose ICS-LABA combination 1, 2
• Alternative (ages 4+): ICS-formoterol as both daily controller AND reliever therapy (SMART regimen) 1, 5
  • This approach reduces exacerbations compared to higher-dose ICS alone or same-dose ICS-LABA with SABA 1

Severe Persistent Asthma

• Preferred: High-dose ICS-LABA combination 1, 2
• Consider adding: Long-acting muscarinic antagonist (LAMA) for triple therapy 1, 2
  • In ages ≥12 years with uncontrolled asthma on ICS-LABA, conditionally recommend adding LAMA 1

Critical Treatment Principles

• Never use LABA monotherapy: LABAs should NOT be discontinued when stepping up therapy in patients already on combination therapy 5
• Avoid chronic oral corticosteroids: Do NOT use for chronic poor control; adjust maintenance therapy instead 5
• SABA overuse signals poor control: Use >2 days/week (not for exercise-induced bronchoconstriction prevention) indicates need to initiate or intensify anti-inflammatory therapy 1, 2

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Essential Non-Pharmacological Management

Patient Education Components

• Provide written asthma action plan to ALL patients including: daily management instructions, signs of worsening asthma, medication adjustments, and when to seek care 2
• Teach proper inhaler technique and verify at EVERY visit; inadequate technique is a common cause of poor control 5, 2
• Educate on medication roles: Distinguish between daily controller medications (ICS, ICS-LABA) and quick-relief medications (SABA, as-needed ICS-formoterol) 2

Environmental Control

• Eliminate tobacco smoke exposure completely 2
• Identify specific allergens through skin testing or specific IgE measurements in patients with persistent asthma requiring daily medications 2
• Reduce exposure to house dust mite, cockroach, cat/dog allergens, and mold in sensitized patients 2

Comorbidity Management

• Treat allergic rhinitis and chronic rhinosinusitis aggressively; consider intranasal corticosteroids 5, 2
• Evaluate and manage: gastroesophageal reflux disease, obesity, anxiety, and depression 2
• Provide annual influenza vaccination for all patients with persistent asthma 2

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Monitoring and Follow-Up

Assessment Parameters

• Use validated tools at each visit: Asthma Control Test (ACT) or Asthma Control Questionnaire (ACQ) 1, 2

  • ACT score <20 indicates not well-controlled asthma 1
  • ACQ minimal important difference: 0.5 1

• Repeat spirometry: At initial assessment, after treatment initiation, during progressive loss of control, and at least every 1-2 years 2

• Document: Nighttime awakenings per week, activity limitations, rescue medication use (puffs per day), and any ED visits or hospitalizations 2

Treatment Adjustment

• Reassess control in 2-4 weeks after initiating or changing therapy 5
• Step up therapy if not well-controlled despite adherence, proper technique, and trigger avoidance 5
• Consider stepping down if well-controlled for at least 3 months 5
• For SMART regimen: Track as-needed ICS-formoterol use; >8 additional inhalations per day signals need for further step-up 5

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Special Considerations for Comorbid Asthma

Asthma with Allergic Rhinitis

• Subcutaneous allergen immunotherapy (SCIT): Conditionally recommend as adjunct in ages ≥5 years with mild-to-moderate allergic asthma whose asthma is controlled during initiation, build-up, and maintenance phases 1
• Do NOT initiate SCIT in patients with uncontrolled asthma 1
• Assess asthma control before EACH SCIT injection using validated questionnaire (ACT) or objective measures (FEV1, peak flow, spirometry) 1
• Withhold SCIT temporarily if asthma worsens until control is restored 1

Acute Severe Asthma Recognition

• Immediate indicators: Accessory muscle use, pulsus paradoxus, refusal to recline, pulse >120 bpm, decreased breath sounds 6
• Objective measures: Peak flow ≤50% predicted/personal best, oxygen saturation <90% 6
• Immediate treatment: High-flow oxygen, nebulized SABA (5 mg salbutamol or 10 mg terbutaline), and oral/parenteral corticosteroids (prednisolone 1-2 mg/kg up to 40 mg in children, 30-60 mg in adults) 1, 6

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Common Pitfalls to Avoid

• Do NOT diagnose asthma on symptoms alone without objective testing 1
• Do NOT use nebulizers for stable asthma; properly used MDIs with spacers are equally effective 5
• Do NOT prescribe antibiotics for exacerbations unless bacterial infection is confirmed 2
• Do NOT use sedation during acute exacerbations; it is contraindicated and dangerous 2
• Do NOT rely on FeNO alone to assess control or predict exacerbations; use as part of ongoing monitoring strategy 1