What is the diagnosis for cough and bilateral wheeze in pediatric (Peds) patients?

Diagnosis: Bronchiolitis or Asthma

In pediatric patients presenting with cough and bilateral wheeze, the diagnosis depends critically on age and wheezing history: children under 2 years with their first wheezing episode most likely have viral bronchiolitis (typically RSV or rhinovirus), while recurrent wheezers or those over 2 years should be evaluated for asthma—but asthma should never be diagnosed on symptoms alone. 1, 2

Age-Based Diagnostic Approach

Children Under 12 Months (First Episode)

• Bronchiolitis is the most likely diagnosis, characterized by tachypnea, wheeze, cough, and crackles following an upper respiratory illness 2
• RSV accounts for approximately 70% of cases, followed by rhinovirus, with viral detection rates reaching 93% 2, 3
• The inflammation causes edema, increased mucus production, and necrosis of epithelial cells in small airways (≤2 mm diameter), producing the characteristic wheeze 2

Children 12-24 Months

• This age group presents the greatest diagnostic challenge with significant overlap between bronchiolitis and early asthma 4
• First-time wheezers should be diagnosed with bronchiolitis, not asthma 3
• Recurrent wheezers in this age range require careful evaluation, as rhinovirus infections and atopic characteristics increase significantly with age and number of previous episodes 3
• Diagnosis patterns vary widely between institutions, with asthma diagnoses increasing from 2% at 3 months to 44% at 23 months of age 4

Children Over 2 Years

• Recurrent episodes of "bronchiolitis" after the first year of life likely represent recurrent wheezing or asthma, not viral bronchiolitis 5
• However, asthma cannot be diagnosed based on cough and wheeze alone—objective testing is required 1

Critical Diagnostic Distinctions

When to Consider Bronchiolitis

• Age under 2 years, particularly under 12 months 2
• First wheezing episode 3
• Preceding upper respiratory symptoms 2
• Presence of crackles/crepitations on examination 2
• Wet/productive cough quality 1

When to Consider Asthma

• Recurrent wheeze is the most important symptom of asthma, not cough 1, 6
• History of multiple previous wheezing episodes 3
• Age over 2 years with recurrent symptoms 5
• Evidence of atopy (eczema, allergic sensitization) 3
• Requires objective confirmation with spirometry (when age-appropriate, typically >6 years) showing reversible airflow obstruction 1, 6

Common Diagnostic Pitfalls to Avoid

Do NOT Diagnose Asthma Based on Symptoms Alone

• The European Respiratory Society strongly recommends against diagnosing asthma based on symptoms alone 1
• Children with chronic cough (>4 weeks) as the only symptom are unlikely to have asthma 1, 6
• Only about 25% of children with cough, wheeze, and exercise-induced symptoms actually have asthma 1
• The sensitivity and specificity of cough as a marker for wheeze in asthma is poor (34% and 35%, respectively) 1

Recognize "Specific Cough" Pointers

• Wet/productive cough suggests protracted bacterial bronchitis, not asthma 1
• Presence of specific cough characteristics requires investigation for underlying disease (bronchiectasis, foreign body, aspiration, cardiac anomalies) 1
• Normal chest X-ray and spirometry are essential to rule out serious pathology 1

Viral Etiology Matters

• RSV-bronchiolitis presents in younger infants with mechanical airway obstruction from mucus and debris 7
• Rhinovirus-induced wheezing is associated with atopic predisposition and higher risk of subsequent asthma development 7, 3
• Rhinovirus infections increase significantly with age and are more common in recurrent wheezers 3

Risk Factors for Severe Disease (Bronchiolitis)

• Age <12 weeks 2, 5
• History of prematurity (especially <32 weeks gestation) 2, 5
• Underlying cardiopulmonary disease 2, 5
• Immunodeficiency 2, 5

Management Implications

For Bronchiolitis

• Supportive care is the mainstay (nasal suctioning, positioning, hydration) 5
• Do NOT use asthma medications (bronchodilators or corticosteroids) unless there is other evidence of asthma 6, 5
• Most cases are self-limited, with 90% of children cough-free by 21 days 5

For Suspected Asthma

• Perform objective testing before initiating treatment: spirometry with bronchodilator response when age-appropriate 6
• Chest radiograph to exclude other pathology 6
• Assessment for true asthma symptoms (recurrent wheeze and/or dyspnea, not just cough) 6
• There is no evidence to support β2-agonists in children with acute cough and no evidence of airflow obstruction 6

For Chronic Cough After Viral Illness

• Do NOT automatically use asthma medications unless other evidence of asthma is present 2, 6, 5
• Consider protracted bacterial bronchitis if wet/productive cough persists—may require 2-week antibiotic course 5
• Follow pediatric-specific chronic cough algorithms 1