Croup and epiglottitis: Clinical sciences

Croup and epiglottitis are causes of acute upper airway obstruction in children. Croup, also known as laryngotracheitis, is a common viral infection, mostly caused by the parainfluenza virus or other respiratory viruses, that results in subglottic inflammation and narrowing. 

On the other hand, epiglottitis is typically a bacterial infection, most often caused by Haemophilus influenzae or Streptococcus pneumoniae, that can cause rapid and life-threatening swelling of the epiglottis and supraglottic structures. 

Signs and symptoms on a focused history and physical examination can help distinguish croup from epiglottitis.

When a patient presents with a chief concern suggesting croup or epiglottitis, first perform an ABCDE assessment to determine if your patient is unstable or stable.

If unstable, stabilize their airway, breathing, and circulation. In some cases, you might need to intubate your patient. Next, obtain IV access, put your patient on continuous vital sign monitoring, including pulse oximetry, respiratory rate, and cardiac monitoring, and don’t forget to provide supplemental oxygen if needed.

Here’s a clinical pearl to keep in mind! Whenever possible, ensure the child’s airway is secured before any anxiety-producing procedures like obtaining IV access. That’s because discomfort and agitation can exacerbate symptoms, increase narrowing of the airway, and ultimately cause an acute airway obstruction.

Once you stabilize the patient, obtain a focused history and physical exam.

If your patient’s caregiver reports a rapid onset of high fever as well as difficulty breathing and swallowing, with drooling and the absence of a cough, you should immediately think of epiglottitis! Physical exam will usually reveal an anxious-appearing child sitting upright with their neck extended in a tripod position, with the chin pushed forward. Additionally, your patient may have a muffled voice and audible stridor with labored breathing.

If you’re able to visualize the pharynx without worsening your patient’s distress, you may even see a cherry-red epiglottis! These signs and symptoms are highly suggestive of epiglottitis, which is a true emergency, so don’t waste any more time and secure the airway emergently!

Now, here’s a clinical pearl! If your patient has a stable airway, or their signs and symptoms do not clearly point to epiglottitis, you can order a lateral neck X-ray. If it reveals a “thumb sign,” as well as swelling of the aryepiglottic folds, you can confirm the diagnosis of epiglottitis.

Once you’ve diagnosed epiglottitis, you should promptly proceed with treatment!

First, perform emergent endotracheal intubation in a controlled setting such as the operating room. Additionally, you should consult the surgical team in advance, for consideration of tracheotomy if an endotracheal tube cannot be placed. Medical management involves empiric IV antibiotics, which commonly consists of a third-generation cephalosporin as well as additional coverage of methicillin-resistant Staphylococcus aureus. Before starting the antibiotics, make sure you obtain cultures of blood and airway secretions, if possible. Culture results may identify the causative bacteria, in which case you can tailor antibiotics.

Now, here’s a high-yield fact! The most common causes of epiglottitis include respiratory pathogens, such as Haemophilus influenzae type B and Streptococcus pneumoniae. Since these bacterial infections are vaccine-preventable, you should have a high index of suspicion for epiglottitis in patients who are unvaccinated.

Now, let’s return to the ABCDE assessment and take a look at stable patients.

In this case, start by performing a focused history and physical exam. A child presenting with symptoms suggesting croup is typically between 6 months and 3 years old, with a low-grade fever and upper respiratory infection symptoms, such as nasal congestion or rhinorrhea. In addition, your patient’s caregiver may describe hoarseness, as well as the rapid onset of a cough that’s barking or seal-like and may worsen at night.

A physical exam typically reveals a child with labored breathing, tachypnea, and normal oxygen saturation. Inspiratory stridor is a common finding, and suprasternal, intercostal, and subcostal retractions may also be present. If your patient presents with these signs and symptoms, you can clinically diagnose croup!

Here’s a clinical pearl to keep in mind! Although croup can usually be diagnosed clinically based on classic history and physical exam findings, in some circumstances, the presentation might not be so clear-cut. If this is the case, you can order a lateral neck X-ray to evaluate the subglottic structures, and consider a viral PCR to identify respiratory viral pathogens. If the neck X-ray demonstrates the “steeple sign,” with subglottic narrowing, or if PCR results are positive for parainfluenza virus, RSV, influenza virus, or adenovirus, you can confirm the diagnosis of croup. 

Also, keep in mind that certain auscultatory findings, such as crackles and wheezing, do not suggest croup, so consider other diagnoses if you hear these!

Now that you’ve diagnosed croup, your next step is to assess the underlying cause.