Croup (laryngotracheitis) is a respiratory syndrome in young children which is usually caused by a viral infection. Severe cases can be life-threatening. Many cases occur in the Fall or early Winter but the condition can occur throughout the year.


Viruses that can cause a laryngotracheitis include:

(1) parainfluenza virus

(2) influenza A or B

(3) adenovirus

(4) rhinovirus

(5) respiratory syncytial virus (RSV)

(6) metapneumovirus

(7) coronavirus

(8) measles


Typical clinical features:

(1) occurs in young children (3 months to 3 years of age, usually under 2 years of age)

(2) often preceded by upper respiratory tract symptoms

(3) presence of stridor (high pitched sound on inspiration)

(4) presence of a hoarse voice or cry

(5) presence of cough, which in fully-developed cases resembles that of a barking seal

(6) worsening of symptoms at night or when the child is agitated

(7) progression to respiratory distress (exhaustion, agitation, cyanosis and air hunger) in severe cases


Less common features:

(1) occurrence in older children, adolescents or adults


Some of the viruses (RSV, influenza) can be detected by rapid diagnostic tests while others require viral culture or PCR.


Treatment may include:

(1) humidified air

(2) epinephrine, usually racemic; L-epinephrine is also effective

(3) steroids (dexamethasone)

(4) intubation if obstruction develops


To read more or access our algorithms and calculators, please log in or register.