1. Definition

• Wheeze is a high-pitched, musical, continuous sound produced by airflow through narrowed airways, typically during expiration.
• Indicates airway obstruction at any level (from trachea to small bronchi).

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2. Initial Assessment

A. ABC Assessment

• Airway: Ensure patency; look for obstruction (secretions, foreign body).
• Breathing:
  • Respiratory rate, effort (retractions, nasal flaring, grunting)
  • Oxygen saturation (SpO₂)
  • Presence and distribution of wheeze
  • Work of breathing (mild / moderate / severe)
• Circulation: Heart rate, capillary refill time, BP, color.

B. Severity Assessment

Severity	Features
Mild	Speaking in sentences, SpO₂ > 94%, mild wheeze
Moderate	Breathless, feeding difficulty, SpO₂ 90–94%
Severe	Cannot talk/feed, SpO₂ < 90%, exhaustion, cyanosis, silent chest

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3. Focused History

Aspect	Key Points
Onset & Course	Sudden (foreign body) vs gradual (infection/asthma)
Frequency/Pattern	Recurrent vs first episode
Triggers	Viral infection, allergen, exercise, cold air, smoke
Associated Symptoms	Fever, cough, coryza, vomiting, feeding difficulty
Past Medical History	Previous wheezing, atopy, eczema, prematurity, GERD
Family/Social History	Asthma, allergies, smoking, housing
Drug history	Recent medications, response to bronchodilators

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4. Physical Examination

• General: Distress, cyanosis, growth, hydration.
• Respiratory system:
  • Chest expansion, use of accessory muscles
  • Percussion (hyperresonant / dull)
  • Auscultation:
    • Wheeze: polyphonic (asthma/viral), monophonic (focal obstruction)
    • Air entry: symmetrical or reduced
    • Crackles: suggest infection or bronchiolitis
• Cardiac: Murmurs (congenital lesions)
• Other systems: Skin (eczema), ENT (allergic rhinitis), clubbing.

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5. Differential Diagnosis

Age Group	Common Causes
Infant (<1 yr)	Bronchiolitis, congenital airway anomalies, aspiration, GERD
Toddler (1–5 yr)	Viral-induced wheeze, foreign body aspiration, asthma
Older child (>5 yr)	Asthma, allergic bronchitis, chronic suppurative lung disease

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6. Investigations

(Usually guided by clinical picture; many cases diagnosed clinically)

• Pulse oximetry – essential.
• Chest X-ray – if first episode, focal findings, suspicion of foreign body/pneumonia.
• Blood tests – if severe or infection suspected.
• Allergy testing / IgE – in recurrent or atopic cases.
• Spirometry / Peak Flow – for older cooperative children (asthma diagnosis).
• Bronchoscopy – if persistent localized wheeze or suspicion of foreign body.

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7. Management

A. Immediate Management

• Mild/Moderate:
  • Nebulized or inhaled salbutamol (via spacer or nebulizer)
  • Oxygen if SpO₂ < 94%
  • Oral prednisolone if known asthma or recurrent wheeze
• Severe / Life-threatening:
  • High-flow oxygen
  • Nebulized salbutamol ± ipratropium bromide
  • IV steroids (hydrocortisone)
  • IV magnesium sulfate / aminophylline / salbutamol if poor response
  • Consider PICU referral

B. Underlying Cause

• Bronchiolitis – supportive (O₂, fluids, suction)
• Foreign body – urgent ENT/pulmonary referral
• Asthma – follow stepwise management (as per BTS/SIGN or GINA)

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8. Long-term Management

• Identify triggers and educate parents on avoidance.
• Asthma education: inhaler technique, action plan.
• Follow-up to reassess control and adjust therapy.

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9. Red Flags

• Silent chest, exhaustion, cyanosis
• Poor air entry or asymmetry
• Persistent localized wheeze
• Failure to thrive or recurrent pneumonia
• Sudden onset without infection (→ foreign body)

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10. Summary Table

Step	Key Action
1	ABC and severity assessment
2	Focused history
3	Physical examination
4	Consider differential diagnoses
5	Targeted investigations
6	Manage acutely + treat cause
7	Educate and follow-up