Croup –  Acute laryngotracheobroncitis

Croup is a form of upper respiratory tract infection seen in infants and toddlers.

It’s characterised by stridor which is cause by a combination of laryngeal oedema and secretions affecting:

  • Laynx
  • Trachea
  • Bronchi


Parainfluenza viruses account for the majority of cases.

Mucosal inflammation and increased secretions

Odema of the subglottic area is dangerous.

It may result in critical narrowing of trachea.

Age: 6 months – 6 years old, peak is 6 months to 3 years


Croup presents as:

  • Mild fever
  • Hoarse voice
  • Barking cough
  • Stridor

Croup is defined as: Mild / Moderate / Severe

 Impending respiratory failure may develop regardless of the severity of the symptoms!!


  • Occasional barking cough
  • No audible stridor at rest
  • No or mild suprasternal/intercostal recession
  • Child is happy and eats / drinks / plays


  • Frequent barking cough and easily audible stridor at rest
  • Suprasternal and sternal wall retraction at rest
  • No or little distress/agitation
  • Child can be placated and is intersted in surroundings


  • Frequent barking cough
  • Prominent inspiratory (occasionaly expiratory) stridor at rest
  • Mark sternal recession
  • Significant distress agitation
  • Or lethargy or restlessness (hypoxaemia)
  • Tachycardia occurs with more sever obstruction symptoms and hypoxaemia

Impending respiratory failure may develop regardless of the severity of the symptoms


If there is any of the following – they override other signs:

  • Change in mental state (lethargy / listlessnesss / decrease level of consciousness)
  • Pallor
  • Dusky appearance
  • Tachycardia

With Impending respiratory failure

  • breathing may be laboured
  • a barking cough may not be prominent
  • stridor at rest may be hard to hear
  • Chest wall recession may not be marked

A child who appears to be deterioration but whose stridor appears to be improving has worsening airway obstruction and is at high risk of complete obstruction

Croup – Who To Admit

Admit patients who are:

  • Cyanotic
  • Pallor
  • Respiratory distress
  • Hypoxaemia
  • Stridor at rest
  • toxic – looking child
  • suspected epiglottitis


Serious diseases with similar presentation (respiratory distress and stridor):


  • Epiglottitis
  • Bacterial tracheitis
  • Peritonsillar abscess
  • Retropharyngeal abscess
  • Layngeal diptheria


  • Foreign body
  • Agnioneutoic oedema
  • Hypocalcaemic tetany
  • Ingestion of corrosives


  • Single dose of oral dexamethasone (0.15mg/kg) to all children – regardless of severity
  • Prednisolone is an alternative if dex not available
  • Budesonide nebuliser is also used and can be useful if the steroid is vomited/not available
  • In really severe situation, nebulised adrenaline can be helpful – it works very well and very quickly, but then it wears off quickly and the airway can become rapidly obstructed. So if you’re using adrenaline – let the anaesthetist know!