Croup

❍ Severity assessment and management

The classic presentation is a child aged 6 months to 5 years with a 1-2 day coryzal prodrome followed by the abrupt onset (often at night) of a seal-like barking cough, hoarse voice, and inspiratory stridor. In mild cases stridor may only be present with agitation or crying; moderate-severe cases have stridor at rest.

Severity guides treatment intensity:

• Mild croup: occasional barking cough, no stridor at rest, no or mild recession, child alert and active. Dexamethasone 0.15-0.3 mg/kg orally; discharge with safety-netting after a period of observation.
• Moderate croup: frequent barking cough, stridor at rest, sternal recession, no or little agitation. Dexamethasone 0.6 mg/kg orally; observe in clinic for improvement before considering discharge.
• Severe croup: prominent stridor, marked recession, significant agitation or altered consciousness, pallor or cyanosis. Medical emergency. Add nebulised adrenaline; refer to secondary care.

Corticosteroids are the cornerstone of management at all severities. A single oral dose of dexamethasone is highly effective, reduces the severity and duration of illness, and decreases hospitalisation and reintubation rates.¹ A single dose is sufficient; repeated doses are not required. Prednisolone (1 mg/kg oral, max 40 mg) is an alternative if dexamethasone is unavailable but is less potent.

For moderate-severe croup or significant respiratory distress: nebulised adrenaline (5 mL of 1 mg/mL solution via nebuliser) provides rapid but temporary (1-2 hours) relief of airway oedema.¹ Any child given nebulised adrenaline must be observed for at least 3-4 hours after the dose for rebound before discharge is considered - hospital admission is usually appropriate. Croup is a clinical diagnosis; neck X-ray (the "steeple sign") is not required and should not delay treatment.²

Humidified air and steam have no evidence of benefit and should not be recommended.³ Cool night air may give mild symptomatic relief; mechanism unclear.

❍ Discharge, safety-netting, and referral criteria

Most children with mild croup who have received dexamethasone and are comfortable after an observation period can be safely discharged home. Discharge advice to families: the cough typically peaks at night and may worsen before improving over the following 2-3 nights; dexamethasone takes up to 6 hours for full effect; return immediately if the child develops stridor at rest, significantly increased work of breathing, pallor or cyanosis, drooling, or appears very unwell.

Refer to secondary care for: moderate-severe croup at presentation; any child given nebulised adrenaline (minimum 3-4 hour observation, admission usually indicated); SpO2 below 92% in air; suspected epiglottitis or bacterial tracheitis (111 call, do not distress child); age under 6 months (narrow airway, higher risk); failure to respond to dexamethasone and adrenaline; or difficulty accessing emergency care if the child deteriorates.

Recurrent croup warrants further review. Most episodes are viral and do not indicate an underlying structural abnormality, but children with frequent recurrence (3 or more episodes) or croup outside the typical age range may benefit from ENT review to exclude subglottic stenosis, haemangioma, or tracheomalacia.