Croup

Question 1

Definition of croup

Answer 1

Also known as laryngotracheobrochitis. A common respiratory disease that typically occurs in children aged between 6 months and 3 years old . Most commonly occurs in the autumn. Viral croup accounts for over 95% of laryngotracheal infection in children.

Question 2

Peak age of presentation in croup

Answer 2

Peak incidence is in the second year of life- uncommon after the age of 6

Question 3

Cause of croup

Answer 3

• Most commonly has a viral cause- typically parainfluenza virus types 1 or 3.
• May also be triggered by rhinovirus, RSV and influenza

Question 4

What is the pathophysiology of croup

Answer 4

Clinical features of croup result from inflammation, swelling of upper airway structures (larynx, vocal cords and trachea), and oedema leading to narrowing of the subglottic region

Question 5

Risk factors for croup

Answer 5

Young age, male sex and previous intubation

Question 6

Presentation of croup

Answer 6

• Characterised by the sudden onset of a ‘seal-like barking cough’ (tracheal oedema and collapse)
• May be accompanied by voice hoarseness, stridor and/or respiratory distress- symptoms are typically worse at night and increase with agitation
• The degree of subcostal, intercostal and sternal recession is a more useful indicator of severity of upper airways obstruction than the RR
• Between 12 and 72 hours: may get prodromal, non-specific URTI symptoms (cough, rhinorrhoea, coryza and fever)
• If obstruction worsens, it can lead to respiratory failure and associated fatigue, hypoxia, hypercarbia, asynchronous chest and abdominal wall motion

Question 7

How can syptoms of croup be categorised

Answer 7

• Mild- seal-like barking cough but no stridor or sternal/intercostal recession at rest
• Moderate- seal-like barking cough with stridor and sternal recession at rest, but no agitation or lethargy
• Severe- seal-like barking cough with stridor and sternal/intercostal recession, as well as agitation or lethargy
• Impending respiratory failure- minimal barking cough, stridor may become harder to hear. Increasing upper airway obstruction, sternal/intercostal recession, asynchronous chest wall and abdominal movement, fatigue, pallor or cyanosis, decreased level of consciousness or tachycardia

Question 8

Investigations for croup

Answer 8

• Croup is largely a clinical diagnosis- when examining the child must take care not to frighten the child (agitation can worsen symptoms)
• Do not reposition the child from the posture they have naturally adopted as this will be one that minimises airway obstruction

Question 9

Croup differentials

Answer 9

Epiglottitis (non-barking cough, sudden onset fever, preferred posture is sitting upright with head extended), bacterial tracheitis, foreign body in upper airway, allergic reaction

Question 10

When should infants be reffered to hospital, what might lwoer threshold for admission.

Answer 10

• Admit all children with moderate or severe illness (and children with impending respiratory failure)
• Consider hospital admission for children with a respiratory rate over 60 breaths/minute or who have a high fever/ toxic appearance
• Threshold for admission should be lower in children with immunodeficiency, chronic lung disease, haemodynamically significant CHD, aged under three months, inadequate fluid intake

Question 11

Management of severe croup

Answer 11

• Give controlled supplementary oxygen if any signs of respiratory distress
• Administer a dose of oral dexamethasone (0.15 mg/kg). Inhaled budesonide (2mg nebulised as a single dose) or IM dexamethasone (0.6 mg/kg) are possible alternatives
• Give nebulised adrenaline (1mg/ml)- provides transient relief whilst waiting for steroids to take effect
• Consider intubation (occurs in 1-3% of cases)

Question 12

Management of mild croup

Answer 12

• Prescribe a single dose of oral dexamethasone (0.15 mg/kg) to be taken immediately
• o Advise parents that symptoms of croup generally resolve within 48 hours (may last up to a week) and that it is generally self-limiting (dexamethasone speeds up the process)
• Encourage use of paracetamol or ibuprofen for fever/pain and to take fluids regularly
• Advise to seek medical attention if the stridor can be heard continually, the skin between the ribs is pulling in with every breath, and if the child becomes restless or agitated (advise to check during the night)
• Advise parents to call an ambulance if the child is very pale, grey, or blue for more than a few seconds, is sleepy or unresponsive or having trouble breathing