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Croup

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Overview

Also known as laryngotracheobronchitis, croup is a common infective cause of stridor in children aged 6 months to 3 years. Parainfluenza viruses make up the majority of cases and infection leads to oedema of the larynx, trachea, and large bronchi, resulting in noisy airflow known as stridor.

Epidemiology

  • Most common in children aged 6 months to 3 years. Uncommon after 6 years
  • Cases occur all year round but hospital admissions peak in late autumn
  • Boys are slightly more commonly affected than girls

Risk Factors

  • Male sex
  • Aged 6 months to 3 years
  • Previous intubation

Presentation

Croup should be suspected in a patient with a sudden-onset seal-like barking cough. Other features include:

  • Stridor
  • Hoarse voice
  • Prodromal fever and coryza for 12-72 hours
  • The cough and symptoms are worse at night or with agitation

Assessment and Admission

Grading severity

NICE recommends the following criteria to grade severity:

  • Mild:
    • Seal-like barking cough
    • No stridor or sternal/intercostal recession at rest
  • Moderate:
    • Seal-like barking cough
    • Stridor and sternal/intercostal recession at rest
    • No (or little) agitation/lethargy
  • Severe:
    • Seal-like barking cough
    • Stridor and sternal/intercostal recession at rest
    • Agitation/lethargy present
  • Impending respiratory failure:
    • Minimal barking cough, stridor harder to hear
    • Increasing upper airway obstruction, sternal/intercostal recession
    • Asynchronous chest wall and/or abdominal movement
    • Fatigue, pallor, decreased consciousness, or tachycardia
    • Respiratory rate >70 /min
    • Chest wall recession may diminish as the child tires

Admission

Admit all children with features of moderate or severe illness, or impending respiratory failure

Consider admission for children with:

  • Respiratory rate >60 /min
  • A high fever or ‘toxic’ appearance (decreased alertness/activity, breathing difficulties, pallor, hypoxia, lethargy, inconsolably irritable)
  • Features of an underlying disorder (e.g. <3 months, chronic lung disease such as bronchopulmonary dysplasia, congenital heart disease, neuromuscular disorders, immunodeficiency, premature infant)
  • Factors affecting a carer’s ability to look after the child (e.g. adverse social circumstances)
  • Longer distance to healthcare in case of deterioration

Differential Diagnoses

Bacterial tracheitis

  • May present with fever and sudden-onset stridor after a viral-like respiratory illness where the patient appears to be recovering but suddenly becomes worse

Epiglottitis

  • Sudden-onset high fever, dysphagia, drooling, non-barking cough
  • The child prefers to sit upright with the head extended
  • Rarely seen due to immunisation against Haemophilus influenzae B

Inhaled foreign body

  • Symptoms such as cough present more suddenly
  • Auscultation shows focal wheezing
  • No fever or prodrome of symptoms of a viral illness

Peritonsillar abscess

  • Dysphagia, drooling, occasional stridor, neck stiffness
  • Unilateral cervical lymphadenopathy
  • The uvula may deviate away from the affected side

Allergic reaction/anaphylaxis

  • There may be a personal or family history of atopy
  • Rashes may be present
  • Wheezing may be seen
  • Hypotension and tachycardia may be seen
  • There may be an identifiable trigger (e.g. peanuts)

Investigations

Most children are diagnosed clinically.

  • If a chest x-ray is performed it may show:
    • Posteroanterior view: subglottic narrowing (steeple sign)
    • Lateral view: swelling of the epiglottis (thumb sign)

Management

Awaiting admission

If the child is being admitted to hospital:

  • Give controlled supplementary oxygen
  • Give single dose of oral dexamethasone (0.15 mg/kg)
    • If the child is too unwell, give single dose inhaled budesonide or single dose of IM dexamethasone
  • Nebulised adrenaline may be considered in emergency cases

Admission not indicated

If admission is not indicated:

  • Prescribe a single dose of oral dexamethasone (0.15 mg/kg) regardless of severity

Patient Advice

  • Symptoms usually resolve within 48 hour
  • Paracetamol/ibuprofen should be given for fever or pain
  • Encourage regular fluid intake and feeding
  • Carers should check on the child regularly, including throughout the night
  • Carers should take the children to hospital if any of the following apply:
    • Stridor can be heard continually
    • The skin between the ribs is pulled in on each breath
    • The child is restless/agitated
  • Parents should call an ambulance if the child:
    • Is very pale/grey/blue (including blue lips)
    • Is unusually sleepy or unresponsive
    • Has features of respiratory distress (abdomen sinking when breathing, skin between the ribs is pulled in on each breath, nasal flaring)
    • Is agitated/upset while struggling to breathe and cannot be calmed down quickly
    • Is unable to talk/drooling/has problems with swallowing, or wants to sit instead of lie down

Complications

  • Bacterial tracheitis:
    • Thought to be due to immune dysfunction following recovery from croup
    • Requires broad-spectrum IV antibiotics and may require intubation
  • Pneumonia:
    • Thought to be due to immune dysfunction following recovery from croup

Prognosis

  • Symptoms usually resolve within 48 hours but some episodes can last for a week

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