Acute laryngitis and croup

Overview

•Barking (seal-like) cough - defining symptom; turbulent airflow through narrowed subglottis

•Hoarse voice - vocal cord mucosal inflammation

•Inspiratory stridor - turbulent flow through narrowed subglottic airway

•Symptoms worse at night - characteristic; key differentiator from epiglottitis

•Low-grade fever - usually present but not high

•No drooling, no dysphagia - important negatives distinguishing from epiglottitis

•Affects children 6 months - 6 years; peak 1-2 years; more common in boys; autumn/winter

Croup vs epiglottitis

Feature	Croup	Epiglottitis
Cough	Barking, seal-like	No barking cough
Fever	Low-grade	High, toxic appearance
Drooling	No	Yes
Voice	Hoarse	Muffled 'hot potato'
Onset	1-2 day coryzal prodrome	Rapid progression
Throat examination	Never - risk of obstruction	Avoid; senior review needed

Investigations

•Croup is a clinical diagnosis - no investigations required in typical presentations

•Pulse oximetry - SpO2 <92% indicates hypoxia requiring oxygen

•AP neck X-ray - 'steeple sign' (subglottic narrowing) if diagnosis uncertain; not routine

•Lateral neck X-ray - only if epiglottitis suspected ('thumbprint sign' in epiglottitis)

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Never perform a throat examination in a child with suspected croup - direct inspection can precipitate complete airway obstruction by provoking laryngospasm.

Management

•All croup: single dose oral dexamethasone 0.15 mg/kg regardless of severity

•If oral not tolerated: nebulised budesonide; if dexamethasone unavailable: oral prednisolone 1 mg/kg

Step 1 · All croup

1. 1Oral dexamethasone 0.15 mg/kg (single dose)
2. 2Corticosteroids reduce subglottic oedema within 1-6 hours

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Mild - no stridor at rest, no recession

Discharge with safety netting advice

Moderate - stridor at rest, no agitation/recession

Give dexamethasone + urgent hospital admission

Severe - stridor at rest + agitation/recession, SpO2 <92%, or signs of exhaustion

Hospital admission + nebulised adrenaline (temporising) + oxygen if SpO2 <92%

⚠️

Nebulised adrenaline is reserved for severe croup only - it is a temporising measure (effect lasts 1-2 hours, rebound possible). Any child receiving it must be admitted and observed for at least 2-4 hours.

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Dexamethasone dose calculation: 0.15 mg/kg. A 12 kg child = 1.8 mg. A 10 kg child = 1.5 mg.

•Acute laryngitis (adults): voice rest, hydration, avoid smoking/alcohol - no antibiotics (almost always viral)

•Hoarseness persisting >3 weeks in an adult - urgent referral to exclude laryngeal malignancy

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A child with severe croup who is tiring may show paradoxically reduced recession - not improvement, but respiratory muscle fatigue. RR >70/min, pallor, cyanosis, or falling consciousness are signs of impending respiratory failure.