In a 5-year-old with a 6-week persistent dry barking cough that worsens at night and with exercise, without fever or recent infection, and a family history of asthma, is this cough-variant asthma and what initial diagnostic and therapeutic steps are recommended?

Clinical Presentation Strongly Suggests Cough-Variant Asthma

This 5-year-old has cough-variant asthma (CVA) based on the classic triad: persistent dry cough for 6 weeks, nocturnal predominance, and exercise-induced symptoms, combined with a strong family history of asthma. The presentation is textbook CVA rather than simple reactive airways disease 1.

Why This is Cough-Variant Asthma

The clinical picture meets established diagnostic clues for childhood asthma 2:

• Family history of asthma or atopy (maternal childhood asthma, paternal aunt with asthma)
• Recurrent cough as the primary symptom
• Night-time disturbance by cough (from bedtime onwards)
• Exercise-induced symptoms (running, scooter riding)

The absence of wheeze does not exclude asthma—cough can be the principal or only manifestation of asthma, especially in young children 1. The 6-week duration qualifies as chronic cough, and the specific triggers (nighttime, exercise) are pathognomonic for CVA 3.

Diagnostic Approach

Since this child is 5 years old, objective testing is feasible and strongly recommended 4:

Immediate Steps:

1. Perform spirometry - This is a strong recommendation for all children aged 5-16 with suspected asthma 4. Look for:

   • FEV1/FVC <80% or <LLN
   • FEV1 <80% predicted or <LLN

2. If spirometry shows obstruction, perform bronchodilator response (BDR) testing 4:

   • Positive if FEV1 improves ≥12% AND ≥200ml after bronchodilator
   • This confirms reversible airflow obstruction

3. If spirometry is normal (which is common in CVA), consider:

   • Bronchoprovocation testing with methacholine when available 1
   • A negative bronchoprovocation test is more helpful to rule out asthma than a positive test is to confirm it 1

Important Caveat:

Do not diagnose asthma based on symptoms alone 4. However, given the strong clinical picture and age-appropriate testing capability, objective confirmation should be pursued.

Therapeutic Approach

Initial Treatment Strategy:

Start a diagnostic-therapeutic trial with inhaled corticosteroids (ICS) 2, 5:

• Use ICS-LABA combination as first-line therapy for CVA, not ICS alone 5
• Continue for at least 8 weeks (CVA requires longer treatment than typical asthma) 5
• Most CVA patients respond to ICS or ICS-LABA 5

Specific Recommendations:

1. For Step 2 treatment (appropriate for this presentation):

   • As-needed low-dose ICS-formoterol is recommended 5
   • This provides both controller and reliever medication

2. Use a large-volume spacer device - Every child given inhaled steroids from an MDI should use this to enhance lung deposition 2

3. Ensure proper inhaler technique - This is critical before considering treatment failure 2

Monitoring Response:

• Schedule follow-up in 2-4 weeks after initiating therapy 5
• Assess:
  • Nighttime cough frequency
  • Exercise tolerance
  • Need for reliever medication
  • School attendance

Diagnosis is confirmed by positive response to asthma medications 1. If cough resolves with treatment and recurs when stopped, this confirms CVA 6.

Alternative Diagnoses to Exclude

While CVA is most likely, the "barking" quality of the cough warrants brief consideration of:

• Habit cough (but the exercise/nocturnal pattern argues against this) 7
• Tracheomalacia (but absence of stridor and presence of exercise/nocturnal triggers favor asthma) 1

The absence of recent URTI, fever, and SOB makes post-infectious cough, pertussis, or other respiratory infections unlikely 7.

Key Management Principles

1. Environmental control: Identify and minimize triggers, especially tobacco smoke exposure 2

2. Parent education on:

   • Difference between "relievers" (bronchodilators) and "preventers" (ICS) 2
   • Recognition of worsening symptoms
   • Proper inhaler technique
   • When to seek help

3. Treatment goals 2:

   • Minimal nocturnal symptoms
   • No limitation on activities/exercise
   • Minimal need for reliever medications
   • No school absences

Common Pitfalls to Avoid

• Don't use the term "reactive airways disease" - This delays proper diagnosis and treatment. Either diagnose asthma or don't 1
• Don't rely on bronchodilators alone - CVA requires anti-inflammatory treatment 5
• Don't stop treatment too early - CVA needs ≥8 weeks of ICS-LABA 5
• Don't diagnose based solely on symptoms - Obtain objective testing when possible 4
• Don't assume normal spirometry excludes asthma - CVA often presents with normal baseline lung function 4

If symptoms persist after 4-8 weeks of appropriate ICS-LABA therapy with confirmed good technique and adherence, consider adding leukotriene receptor antagonist or short-term oral corticosteroids (10-20 mg/day for 3-5 days), as CVA has different phenotypes with varying treatment responses 5.