Croup

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It’s 2230 and Roberto, 2, is sitting in triage when, from across the department you hear a seal-bark cough. He becomes distressed and is quickly bundled into the resus bay by the worried triage staff. You hear a biphasic stridor and can see some intercostal recession. Roberto’s parents are worried and tearful.

Bottom line:

  • Croup is viral laryngotracheitis
  • Consider the “Big Four” Differentials
  • Keep everyone calm
  • Assess the severity
  • Give steroids early
  • Think critically about your management

So, what is croup?

Croup is also known as laryngotracheitis. It’s an inflamed larynx and trachea, secondary to viral infection. It can occasionally progress to laryngotracheobronchitis; involving the bronchi.

Who gets it?

Croup is most prevalent in the 6–36 month age group, and boys are affected more often than girls. A positive family history is associated with a four-fold likelihood of having croup.

According to a US study, only 1 in 20 require admission to hospital (re-presentation rate ~1 in 20 of DEM discharges within 48hrs).

The most common cause of croup is Parainfluenza virus type 1 (PIV1), which peaks in infection rates every two years. Judging from the increased number of presentations so far this autumn, here in Australia, it’s a “croup year”. Sporadic cases of croup are often due to PIV3, which reportedly can be more severe.
(See graph)

What’s all the noise about?

  • Tracheal narrowing at sub-glottic level
  • Fixed obstruction
  • Dynamic obstruction

The clinical presentation of croup has some hallmark features:

Barking cough
Hoarse voice
Stridor

Additionally, you may identify:

  • Presentation to hospital in the evening and at night
  • Gradual onset 12-48 hrs
  • Coryza
  • Febrile

Features that are not consistent with croup:

  • Toxic looking child
  • Drooling
  • Posturing to protect airway
  • Sore throat

If you remember nothing else from this post, it’s to consider the differential diagnoses for croup. The big four:

  1. Acute epiglottitis
  2. Bacterial tracheitis
  3. Foreign body, inhaled or aspirated
  4. Allergic reaction / anaphylaxis

These can be life threatening. Consider them in every patient who is stridulous or has a barking cough.

Also consider:

  • Peritonsillar & retropharyngeal abscess
  • Upper airway injury
  • Congenital upper airway anomalies
  • Acute angioneurotic oedema
  • Neck mass
  • Laryngeal diphtheria
  • Measles

Okay, you’re satisfied that Roberto has croup. How bad is it?

There are a few different scoring systems to ascertain the severity of croup. The Westley croup score was first described in 1978 for a trial comparing nebulized adrenaline vs saline for croup. The scoring system, shown below, heavily weights more ominous signs, and is more for the purpose of research than clinical usage.

Westley Croup score
RCH Melbourne

What is the treatment?

Always:
Keep the child calm.
Keep the parents calm.

Mild / Moderate:
PO Dexamethasone or PO Prednisolone.
A period of observation.

Severe:
Adrenaline, nebulised (5mL of 1:1000)
IM/IV Dexamethasone 0.6mg/kg (max 12mg)
Admit & observe

Where do you stand on the controversies?

The management of croup is an ongoing debates in Paediatrics, with strong opinions. We’d love you to comment below to voice your thoughts on each of these…

Adrenaline: It’s a no-brainer to use adrenaline in severe croup. The controversy is around the a) a threshold for nebulized adrenaline and, b) the use of multiple doses of nebulized adrenaline.

The 2013 Cochrane Review states:

“Compared to no medication, inhaled epinephrine improved croup symptoms in children at 30 minutes following treatment (three studies, 94 children). This treatment effect disappeared two hours after treatment (one study, 20 children). However, children’s symptoms did not become worse than prior to treatment. No study measured adverse events.”

Indeed, Westley’s 1978 study had similar findings to this much more recent review.

Anecdotally, we tend to see a fair amount of adrenaline overuse, in lieu of keeping the child calm. Indeed, nebulised adrenaline can have the opposite effect; putting something on the child’s face, wrestling with them and giving the child a tachycardia (distress, not adrenaline). The ‘need’ for this treatment can also convey an overly worried demeanor to child & parents, further distressing everyone.

Steroids: Oral dexamethasone (and the dosage) vs oral prednisolone has been the topic of a number of studies in the last two decades, with regular publications in favour of either. Check your local guidelines and preferences, and give the steroids early. For what it’s worth, I lean towards dexamethasone – it’s longer acting and may just reduce the inflammation enough to account for a second night of symptoms. Again, we’d love you to comment below.

What’s the prognosis?

Croup is NOT a benign self limiting illness. It’s an illness that is usually benign and self limiting but can very definitely kill you.
Once the initial airway compromise is managed with steroids, further sequelae are very rare.
Nonetheless, ~3 in 1000 cases require intubation, with
<0.5% mortality in intubated patients.
Kids should never be discharged with a stridor at rest!

Roberto settles down for the night in short stay, and can be hear breathing quietly when you check him through the night. He goes home after tucking into a large breakfast.

South, M. Croup – Clinical Practice Guidelines. The Royal Children’s Hospital, Melbourne. www.rch.org.au 27 April 2014.

Russell KF et al., Glucocorticoids for croup (Review), 2011. Cochrane Collaboration

Cronin et al. Single dose oral dexamethasone versus multi-dose prednisolone in the treatment of acute exacerbations of asthma in children who attend the emergency department: study protocol for a randomized controlled trial. Trials 2012, 13:141

Bjornson C et al., Nebulised epinephrine for croup in children (Review), 2013. Cochrane Collaboration

Port, C. via BestBets: Dose of dexamethasone in croup. 2009. http://bestbets.org/bets/bet.php?id=502

Winckworth, L. via BestBets: Is oral prednisolone as effective as oral dexamethasone in treating mild to moderate croup? An update. 2011. http://bestbets.org/bets/bet.php?id=2080

C. Ross Westley, MD; Ernest K. Cotton, MD; John G. Brooks, MD Nebulized Racemic Epinephrine by IPPB for the Treatment of Croup: A Double-Blind Study Am J Dis Child. 1978;132(5):484-487.

Rihkanen H, Rönkkö E, Nieminen T, et al. Respiratory viruses in laryngeal croup of young children. J Pediatr 2008; 152:661.

Fry AM, Curns AT, Harbour K, et al. Seasonal trends of human parainfluenza viral infections: United States, 1990-2004. Clin Infect Dis 2006; 43:1016-22.

 

 

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A Paediatric Trainee based in Queensland, Australia, Henry is passionate about Adolescent Medicine & General Paediatrics, with a strong interest in Medical Education & Clinical Teaching. An admitted nerd & ironman with a penchant for Rubik's Cubes & 'Dad jokes'.

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2 Responses to "Croup"

  1. Penny Wilson
    Penny Wilson 3 years ago .Reply

    Hi Henry,
    Thanks for the post.
    For those of us in GP land – what do you think about the kids with croupy cough who don’t have any stridor or respiratory distress. Should we be giving them all steroids? Should we give them steroids to take home and take if they get worse at night? I was always taught that the steroids don’t actually help the cough, they just reduce the risk of progressing to more severe respiratory distress and requiring intervention. Is there any updated evidence on that?
    Cheers
    Penny

  2. Ben Lawton
    Ben Lawton 3 years ago .Reply

    Hi Penny
    my view on that is to have a very low threshold for treatment. At the end of the day croup is a potentially life threatening illness and the kind of steroid doses we are talking about for treatment have a minimal side effect profile while being quite efficacious in preventing more severe symptoms. You have to be aware of how often that particular child is getting steroids as frequent dosing (to me that means more than 3-4 times per year) is starting to become more of a concern for long term side effects – though this concern is minor when compared to the danger of untreated croup. I would think it reasonable to treat a clear croupy cough in the absence of stridor and in most circumstances to refer anyone with stridor at rest and certainly anyone with respiratory distress to hospital (via ambulance where appropriate). Our local ambulance service use stridor at rest as an indication for nebulised adrenaline (which I think is a bit heavy handed in the hospital context but perfectly reasonable pre-hospital) and I would certainly not be discharging a croup pt from my ED while they still had stridor at rest. My concern about prescribing take home steroids for the parents to use should the child become more distressed would be that they may use that steroid to treat symptoms that require more significant intervention and hence not call 000 when maybe they should so I would tend to avoid that practice. Your assertion that steroids don’t help the cough but do reduce the risk of progression of respiratory symptoms is an important point for the parents to understand. Hope that is helpful. Ben

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