About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- Cough & Wheeze in a Child is managed by first identifying emergency red flags before considering benign explanations
- Use the child’s age, appearance, hydration/perfusion, growth/development, and caregiver context to structure the differential
- The differential diagnosis table is the centrepiece: rule out must-not-miss diagnoses before common self-limited causes
- Investigations should be targeted rather than broad; avoid low-value tests when the child is well and the pattern is clear
- Management combines stabilization, cause-specific treatment, safety-netting, and family-centred communication
Approach to the Presentation
Cough & Wheeze in a Child is approached as a paediatric clinical presentation rather than a single diagnosis. The first task is to decide whether the child is unstable or has a red flag. The second is to use age, trajectory, associated symptoms, examination, growth/development, and family context to prioritize must-not-miss diagnoses. Canadian practice should align with CPS, PHAC/NACI, Choosing Wisely Canada, and local provincial/territorial pathways where relevant. Paediatric cough and wheeze requires rapid assessment of work of breathing, oxygenation, age, and pattern — croup, bronchiolitis, asthma, pneumonia, and foreign body must be separated early
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Severe Asthma / Status Asthmaticus | must-not-miss | Inability to speak/cry/feed, accessory muscles, silent chest, fatigue, hypoxia | Clinical severity assessment |
| Pneumonia | must-not-miss | Fever, tachypnea, hypoxia, focal crackles, reduced breath sounds, grunting | Clinical; CXR if severe/uncertain |
| Foreign Body Aspiration | must-not-miss | Sudden choking/cough, unilateral wheeze or decreased air entry | CXR may be normal; bronchoscopy if high suspicion |
| Epiglottitis / Bacterial Tracheitis | must-not-miss | Toxic, high fever, drooling, tripod, muffled voice, severe stridor | Clinical airway emergency |
| Croup | common | Barking cough, hoarseness, inspiratory stridor, worse at night | Clinical |
| Bronchiolitis | common | Infant <2 years, first wheeze, viral prodrome, crackles/wheeze, feeding difficulty | Clinical |
| Viral-induced Wheeze / Preschool Asthma | common | Recurrent wheeze with viral triggers, atopy, salbutamol response | Clinical pattern and response |
| Pertussis | less common | Paroxysmal cough, whoop, post-tussive vomiting, apnoea | Nasopharyngeal PCR/culture |
| Anaphylaxis | less common | Acute wheeze/stridor with urticaria, vomiting, hypotension | Clinical; IM epinephrine |
| Cystic Fibrosis | rare | Chronic cough, recurrent infections, poor growth, greasy stools | Sweat chloride/CFTR testing |
Red Flags & Key History
Symptoms
Apnoea, cyanosis, exhaustion, poor feeding, reduced responsiveness
Severe work of breathing, inability to speak/cry/feed, silent chest
Drooling, tripod position, muffled voice, toxic appearance
Sudden onset after choking episode
Fever with focal chest pain, grunting, or hypoxia
Prematurity, congenital heart disease, chronic lung disease, immunocompromise
Typical mild symptoms in a well child with normal hydration/perfusion and reliable follow-up
Signs
Toxic appearance, altered responsiveness, poor perfusion, or respiratory distress
Abnormal growth, hydration, neurological, abdominal, skin, or musculoskeletal findings
Focal signs that localize infection, surgical disease, trauma, or inflammatory disease
Findings inconsistent with the history or developmental stage
Normal examination with stable course and clear benign pattern
Approach to Investigation
First-line
Pulse oximetry and respiratory severity assessmentFirst-line assessment for this presentation; interpret in clinical context
Clinical syndrome recognitionHigh-yield initial test or examination component
Chest X-ray only if severe, focal, hypoxic, uncertain, or foreign body suspectedUse when red flags, dehydration, systemic illness, or diagnostic uncertainty are present
Blood gas if impending respiratory failureTargeted testing rather than broad screening whenever the child is stable
Second-line
Focused imaging or advanced testingUse when first-line assessment suggests surgical, neurological, infectious, inflammatory, or structural disease
Microbiology or serologyUse when public health, infection control, travel, outbreak, immunocompromise, or treatment decisions depend on organism identification
Serial reassessmentImportant when early disease may not yet declare itself
Targeted screening for mimicsUse when presentation is persistent, recurrent, atypical, or associated with poor growth/development
Specialist
Paediatrics or emergency specialistFor unstable child, diagnostic uncertainty, admission need, or high-risk features
Subspecialty consultationSurgery, neurology, infectious diseases, gastroenterology, nephrology, endocrinology, child protection, or public health depending on presentation
Management Principles
Canadian Paediatric Society bronchiolitis/croup guidance and Canadian respiratory practice1
Immediate priorities
- Assess ABCs, vital signs, hydration/perfusion, pain, glucose when relevant, and need for urgent escalation
- Treat shock, hypoxia, seizures, severe dehydration, suspected sepsis, or surgical abdomen without delay
- Use age-appropriate analgesia and family-centred communication
2
Targeted management
- Treat the most likely or confirmed cause using Canadian/local guidance
- Avoid low-value investigations and therapies in typical benign presentations
- Arrange appropriate follow-up, reassessment, and return precautions
3
Family and safety-netting
- Explain expected course, red flags, and when to return
- Assess caregiver capacity, access to fluids/medications/transport, and social supports
- Escalate safeguarding concerns according to provincial/territorial law
Complications & Pitfalls
- Premature closure: do not diagnose a benign condition before red flags are excluded.
- Age-blind assessment: neonates, infants, school-aged children, and adolescents have different risks.
- Low-value testing: broad testing can distract from careful history, examination, and targeted investigation.
- Poor safety-netting: discharge requires explicit return precautions and reliable follow-up.
MCCQE1 Exam Tips
- 1Croup: barking cough + hoarse voice + stridor; dexamethasone, nebulized epinephrine if stridor at rest
- 2Bronchiolitis management is supportive, not routine salbutamol/steroids/CXR
- 3Silent chest in asthma is ominous
- 4Sudden unilateral wheeze after choking suggests foreign body
- 5Drooling/tripod toxic child is airway emergency
- 6Do not order routine CXR for typical bronchiolitis or croup
- 7CanMEDS collaborator: severe respiratory distress requires early help
practicetest your knowledge on cough & wheeze in a childApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — paediatric and beyond.
open q-bank