Croup

Croup is a clinical syndrome of upper airway obstruction defined by barking cough, stridor, and hoarseness. Management hinges on severity assessment, universal corticosteroid use, and selective epinephrine. The key clinical task is distinguishing typical croup from high-risk mimics that require urgent airway intervention.

Learning Objectives

1. Differentiate croup from other causes of pediatric upper airway obstruction using key historical and physical exam features.
2. Apply a severity-based approach to croup management, including appropriate use of corticosteroids and nebulized epinephrine.
3. Recognize clinical features that suggest alternative or life-threatening diagnoses requiring escalation of care.

References

1. Cooke A, Conway S, Griffin L. Croup: Rapid Evidence Review. Am Fam Physician. 2026;113(3):254-258.
2. Gates A, Johnson DW, Klassen TP. Glucocorticoids for Croup in Children. JAMA Pediatr. 2019;173(6):595-596. doi:10.1001/jamapediatrics.2019.0834
3. Bjornson CL, Klassen TP, Williamson J, et al. A Randomized Trial of a Single Dose of Oral Dexamethasone for Mild Croup. N Engl J Med. 2004;351(13):1306-1313. doi:10.1056/NEJMoa033534
4. Bjornson CL, Johnson DW. Croup. Lancet. 2008;371(9609):329-339. doi:10.1016/S0140-6736(08)60170-1
5. Bjornson C, Russell K, Vandermeer B, Klassen TP, Johnson DW. Nebulized Epinephrine for Croup in Children. Cochrane Database Syst Rev. 2013;(10):CD006619. doi:10.1002/14651858.CD006619.pub3

Transcript

This transcript was generated using Descript and subsequently reviewed and lightly edited for spelling, grammar, and clarity. Minor inaccuracies may remain, and the audio recording should be considered the definitive version of this content.

 Welcome to PEM Currents: The Pediatric Emergency Medicine Podcast. As always, I’m your host, Brad Sobolewski. And today we’re gonna talk about croup. We’re gonna focus on diagnosis, severity based management, and how to differentiate it from scarier high risk conditions that may present similarly, but behave very differently.

So croup is best understood as a clinical syndrome of upper airway obstruction caused by inflammation at the level of the larynx and subglottis. So in most cases this is viral laryngotracheitis, most commonly due to parainfluenza virus. But as you’d expect multiple viruses can cause it. The subglottis is the narrowest portion of the pediatric airway.

So even small amounts of edema create large increases in airway resistance. So that’s why the clinical picture is so consistent. You’ve got inspiratory stridor, hoarseness, and that characteristic barking cough, which either sounds like a seal or a dog, and yes, of course, I know the difference between the two coughs because I was a biology major.

This is primarily a disease of children between six months and three years of age with a peak incidence in the second year of life. It’s really, really common, like one and a half percent of all ED visits, maybe 350,000 visits a year, and 85% of these kids have mild disease. Hospitalization is rare. The range is variable, about two to 8% of cases, and return visits occur in about three to 5%. Fewer than 1% of children, a lot fewer, require intensive care or airway intervention. Honestly, most kids do really well. The ones who don’t can get sick very quickly, and that’s been my clinical experience.

In the Northern Hemisphere, we see croup throughout the fall and winter, usually starting in around November and sort of tapering off by April. But that being said, I’ve seen croup-like symptoms every month of the year over the past couple of decades.

Croup is absolutely a classic clinical diagnosis. A typical case begins with 12 to 48 hours of viral prodrome, you know, body aches, fever, congestion, cough, followed by often abrupt nighttime onset of barky cough and stridor. Symptoms fluctuate, and they’re generally worse with agitation and get better when the kid is calm. That variability is the key feature.

So what you’ll have is a child who wakes up after sleeping for a few hours with a barky cough and then noisy stridor. This freaks parents out, and this is not hyperbole. There’s this little center in the back of your brain that’s like, please don’t stop breathing and die. So appropriately, they’re worried about the kid, they call emergency medical services, they bring them to the emergency department, and by and large, by the time they get there, the stridor has resolved. The kid is calm, and parents will say, I swear he looked a lot worse at home. Trust me, we believe you parents, this is what croup does.

When I’m taking a history of croup, I get all of these details. Are there any sick contacts? If the parents are worried about a foreign body inhalation or ingestion, then I’m worried about a foreign body inhalation or ingestion. Listen to the lungs, inspect their airway. Always check the ears for concomitant otitis and I’ll feel their trachea. I’ll actually grab and hold the trachea and move it. Kids with croup really don’t have a painful trachea. Kids with bacterial tracheitis, aside from looking more toxic, actually have a lot of pain when they move their trachea.

Testing for croup is generally unnecessary. Labs and viral studies do not change management, and imaging is really reserved for atypical presentations or when you’re considering an alternative diagnosis like a foreign body. If you do get an X-ray, what you’re looking for is the classic steeple sign on the AP view. It is seen in croup, but it’s not 100% sensitive nor specific.

Once you’ve made the diagnosis of croup, it’s important to assess severity, and remember that I said that most kids are mild. So mild croup is defined by the absence of stridor at rest. So they may have some stridor when they’re upset or even a little bit of hoarseness or noise. It’s important to listen to many, many children with croup to get a sense of this.

Moderate croup includes stridor at rest with mild to moderate retractions. So at rest means that the child is in a position of comfort. They’re calm with a parent, and they’ve generally been that way for about 10 to 15 minutes. Sometimes that’s how long it can take for the stridor to dissipate once you get the kid calm.

Severe croup, which is fortunately rare, involves marked work of breathing, agitation, fatigue, need for oxygen, altered mental status, and this aligns with the Westley croup score. It formalizes stridor, retractions, air entry, cyanosis, and mental status. But really, in practice, most of us get very good at bedside assessment of croup.

Management of croup starts with corticosteroids. This is one of the highest-yield interventions that we have in pediatric emergency medicine. Every child with croup should receive dexamethasone. Typically 0.6 milligram per kilogram as a single dose up to a maximum of 10 milligrams. Some places will use 0.15 milligram per kilogram.

Locally, we often give the IV formulation orally. It’s 10 milligrams per mL. Tastes bad, but pairs reasonably well with apple juice. The oral suspension is 1 milligram per mL, tastes terrible, and pairs nicely with being spit on the ground by toddlers.

The evidence behind dexamethasone is very robust. The main benefit is that it reduces return visits and hospital readmissions by about half, and those return visits include doctor’s offices and emergency departments. In a Cochrane review of 1,679 children, glucocorticoids reduce return visits or readmissions with a risk ratio of 0.52, so that translates to a number needed to treat of seven.

I’ve certainly seen seven or more croup kids during one shift, so for every seven children treated with dexamethasone, one return visit is prevented. Symptom improvement begins within about two hours and lasts at least 24 hours, but maybe up to a couple of days. Hospital length of stay for kids that get steroids is reduced by an average of 15 hours as well. Serious adverse events are rare. It’s well tolerated, and other than the taste, kids do fine with it. And importantly, the benefit is consistent across all severities of croup, mild, moderate, and severe.

So when you explain this to families who are very scared about their kids, but now their kid is looking better and you’re only giving them a single medicine, not doing any tests or X-rays or anything, I think you have to frame the medicine in terms of what it’s going to do for them over the next couple of days.

So one way of explaining this to families would be to say something like this is a steroid called dexamethasone. It reduces the swelling in your child’s airway that’s causing the barky cough and noisy breathing. Most children start feeling better within a couple of hours, and the benefit lasts at least a full day, if not longer.

Without this medicine, about one in five children need to come back because symptoms get worse again. You really get two bad days with croup in most cases. With this medicine, the risk of returning drops to about one in 10, so it cuts the chance of coming back in half.

We can expect your child’s cough to start improving over the next day or two. Most children are feeling a lot better within 48 hours, though a little bit of hoarseness and cough can last for a week to about 10 days.

So it’s possible that when your child goes to sleep later tonight, they may experience that barking cough and noisy breathing again. They’re almost certainly going to be upset. The steroid blunts enough of the swelling so that you are much more likely to have them free of distress and stridor, that noisy breathing, once you get them calm.

So if they’re upset, get them calm, and if in about 10 minutes the stridor and noisy breathing get better, that’s the dexamethasone doing its job and you can safely stay home.

For children with moderate or severe croup, we’re gonna use nebulized racemic epinephrine. It works fast by reducing airway edema by constricting inflamed blood vessels. You’ll see improvement in stridor and work of breathing often within 30 minutes. The effect is transient and largely gone by about two hours, and you need to do a structured reassessment at about 30 minutes after the racemic epinephrine.

If the child’s clearly better, continue that observation for up to two hours. If they’re unchanged or worse, repeat the epinephrine and start thinking more carefully about your diagnosis and disposition. Because it’s got such a short duration, that two hours after treatment is the most common time period, though some institutions and some children will need to be observed a little bit longer.

If they remain well appearing with no stridor at rest, normal oxygenation, minimal work of breathing, and they can tolerate oral fluids, they can be discharged. If symptoms recur, they require repeated epinephrine, or they fail to improve, then you may have to escalate care and consider admission.

Honestly, with croup, supportive care is still one of the most important things. You gotta keep kids calm by minimizing agitation. Parents are experts at this with their own children. Agitation worsens airway obstruction. Airway resistance is fourfold greater when the kid’s upset.

Give oxygen if the kid’s hypoxic. Fortunately, this is rare. Antipyretics and fluids are great, do them. Humidified air has not been shown to provide meaningful benefit, and obviously we should avoid sedatives because they can suppress respiratory drive without improving airway patency.

Many parents will say that their kid was better when they were exposed to cool air or mist in the shower. Those can help, but honestly, don’t stick your kid’s head in the freezer if it upsets them. Keep them calm, hold them, and comfort them.

Alright, croup, barking cough, stridor, variable symptoms, easy, right? There are some other diagnoses that can mimic this or overlap that you shouldn’t miss.

Spasmodic croup is a related phenotype. You’ve got sudden nighttime onset, often minimal prodrome, and recurrent episodes. These kids are typically well between episodes, and the pattern becomes more apparent over time. Some kids will bark with every mild cold or stuffy nose up until about eight or nine, but they usually don’t have stridor and respiratory distress.

Bacterial tracheitis is progression to a more severe and dangerous airway infection. These children often start with viral symptoms and then rapidly worsen. They’ve got a high fever, they appear toxic. Most importantly, they fail to respond to standard croup therapy. Toxic appearance plus lack of response should immediately shift your diagnostic reasoning.

These kids may have a lot of pain when you grab and move their trachea. The cough can be more junky because again, they’ve got purulent mucus in their trachea.

Epiglottitis is defined by the absence of barking cough and the presence of drooling, dysphagia, and tripod positioning. These children are very anxious, they’re very ill, their airway is at risk, and so your immediate priority is keeping them calm and having the airway managed in the safest environment, generally the operating room.

Deep neck space infections, including retropharyngeal cellulitis and abscesses and peritonsillar abscesses, present with fever, neck stiffness, sometimes even torticollis, and lymphadenopathy. Kids won’t really have a barky cough and the exam localizes to the neck rather than the airway alone.

Acute foreign body aspiration presents with sudden onset symptoms, no viral prodrome, no barking cough, and sometimes some asymmetric exam findings. The diagnosis is frequently missed when clinicians anchor too early on croup.

If you have an esophageal foreign body, remember that 70% of these get stuck at the thoracic inlet. So always think about a kid who sounded like they had croup and got croup treatments, but also has some swallowing issues and is the right age to put things in their mouth. This is when you see coins and button batteries and other things stuck not in the upper airway, but in the esophagus right behind it.

Alright, now when it comes to disposition, most kids with croup are gonna be sent home. Children who improve, they have no stridor at rest, minimal work of breathing, can be discharged home with clear return precautions. Those with persistent symptoms, need for repeated racemic epinephrine, hypoxia, or concerning features should be admitted.

For kids who continue to worsen despite standard therapy, escalation includes high-flow nasal cannula, noninvasive ventilation as a bridge. Heliox can be used as a temporizing measure to reduce work of breathing.

Fortunately, needing to intubate a child with croup is rare, but when it’s needed, it can be challenging due to subglottic narrowing. You need the best proceduralists, and you should downsize your endotracheal tube by 0.5 to 1 millimeter smaller than usual.

And I’ll reiterate this again. The natural course of croup is really favorable for most kids. The fear’s not gonna go away for the parents, this is a scary diagnosis, but I think with some reassurance, we can help them understand that this is something that is unlikely to cause significant problems and will get better.

Most kids improve significantly within 48 hours, though like any other respiratory illness, symptoms can persist for a week or so. Severe outcomes are fortunately rare, and they almost always occur in children whose severity or alternative diagnosis was not recognized early.

So again, here’s my take-home points. Croup is a clinical diagnosis. Severity determines your management. Steroids, dexamethasone, should be given to all patients. Racemic epinephrine is used for moderate to severe disease with mandatory reassessment and observation. And most importantly, always reassess the diagnosis when the presentation does not fit the expected patterns.

Things can get rough when you’re barking up the wrong tree and thinking it’s croup when it’s actually something else.

Well, I hope you enjoyed this episode on honestly one of the most classic conditions that we see in the pediatric emergency department. If you’ve got any feedback on the episode, send it my way.

As the kids would say, like, rate, and review. I would love it if you left a review on your favorite podcast site. It helps more people find the show. I do this as a labor of love because I enjoy teaching, and I think that this is a wonderful way to reach my colleagues and learners.

If you’ve got suggestions on other topics or episodes, I’d love to hear them.

For PEM Currents: The Pediatric Emergency Medicine Podcast, this has been Brad Sobolewski. See you next time.