What is the differential diagnosis and management for a 3-year-old child with a persistent cough, no fever, normal chest exam, and no improvement with steroids and albuterol (beta2-adrenergic agonist)?

Chronic Cough in a 3-Year-Old: Differential Diagnosis and Management

Given the lack of response to steroids and albuterol, this is most likely protracted bacterial bronchitis (PBB) if the cough is wet/productive, or a post-viral cough if dry, and you should immediately assess whether the cough is wet or dry to guide your next steps. 1

Critical First Step: Characterize the Cough

You must determine if this is a wet/productive cough versus a dry cough, as this fundamentally changes your diagnostic approach and treatment. 1

• Ask the parents specifically: Does the child sound "rattly" or "chesty"? Is there mucus production? 1
• Listen carefully during the visit for the quality of the cough 1
• This single distinction has sensitivity of 1.0 and specificity of 0.95 for identifying a specific cause requiring treatment 1

Differential Diagnosis Based on Cough Type

If WET/PRODUCTIVE Cough:

Most likely diagnosis: Protracted Bacterial Bronchitis (PBB) 1, 2

• PBB is the most common cause of chronic wet cough in children without specific cough pointers 2, 3
• Caused by bacterial infection (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis) 2
• The normal chest exam and lack of fever do NOT rule this out 2

Other considerations for wet cough:

• Bronchiectasis (look for digital clubbing, failure to thrive, recurrent infections) 1
• Aspiration (coughing with feeding, recurrent pneumonias) 1
• Retained foreign body (sudden onset, unilateral findings) 1

If DRY/NON-PRODUCTIVE Cough:

Most likely diagnosis: Post-viral cough or acute bronchitis 1

• This typically resolves spontaneously within 2-4 weeks 1
• The lack of response to albuterol and steroids argues AGAINST asthma 4, 5

Other considerations for dry cough:

• Upper airway cough syndrome (post-nasal drip from recent URI) 3, 6
• Psychogenic/habit cough (absent during sleep, present during day, may have stressors) 7, 8
• Foreign body (sudden onset, persistent despite treatment) 1
• Pertussis (paroxysmal cough, post-tussive vomiting, inspiratory whoop) 2

Immediate Management Algorithm

Step 1: Obtain Chest Radiograph

• This is mandatory for all children with chronic cough (>4 weeks) 1
• While not sensitive, it is highly specific—abnormalities indicate disease requiring further workup 1
• Rules out serious pathology like foreign body, pneumonia, or structural abnormalities 1

Step 2: Treatment Based on Cough Character

If WET cough with normal CXR:

• Prescribe 2 weeks of antibiotics targeting respiratory bacteria (amoxicillin-clavulanate is typical choice) 2, 3, 6
• Reassess in 2 weeks 2, 3
• If cough persists after first course, prescribe ANOTHER 2-week course of antibiotics 2, 3
• If cough persists after 4 weeks total of antibiotics, refer to pediatric pulmonology for bronchoscopy and further evaluation 1, 2

If DRY cough with normal CXR:

• Watch, wait, and review in 2-4 weeks 1
• Most will resolve spontaneously (post-viral cough) 1
• Do NOT continue steroids or albuterol if no other features of asthma are present 1, 3, 6
• Evaluate for environmental triggers (tobacco smoke, pollutants) 1

Key "Specific Cough Pointers" That Require Immediate Further Workup

If ANY of these are present, this is NOT simple PBB or post-viral cough and requires extensive investigation: 1

• Digital clubbing 1
• Failure to thrive or poor weight gain 1
• Coughing with feeding or swallowing 1, 6
• Chest wall deformity 1, 2
• Cardiac abnormalities on exam 1
• Hemoptysis 3
• Daily moist/productive cough from birth 1
• Recurrent pneumonias 1

Common Pitfalls to Avoid

Do not continue asthma treatment when there is no response and no other asthma features 1, 3, 6

• The lack of response to steroids and albuterol strongly suggests this is NOT asthma 4
• Continuing ineffective treatment delays correct diagnosis 6

Do not assume this is GERD without gastrointestinal symptoms 6

• GERD treatment should not be used empirically for isolated cough 6

Do not use over-the-counter cough suppressants 3

• These are ineffective and potentially harmful in young children 3

Do not miss a foreign body 1

• Ask specifically about choking episodes or sudden onset of cough 1
• Consider bronchoscopy if history is suggestive even with normal CXR 7

When to Refer to Pediatric Pulmonology

Refer if: 1, 2, 3

• Wet cough persists after 4 weeks of appropriate antibiotics 2
• Any specific cough pointers are present 1
• Abnormal chest radiograph 1
• Recurrent episodes despite appropriate treatment 3
• Parental anxiety is high and diagnosis remains unclear after systematic evaluation 1