Croup vs Epiglottitis Tips TMC CSE Exam Vector

Croup vs. Epiglottitis: Tips for the TMC/CSE Exams (2025)

by | Updated: Jan 29, 2025

Croup and epiglottitis are two pediatric respiratory conditions that share similar symptoms but require distinct management strategies. For respiratory therapists preparing for the TMC and CSE exams, understanding the differences between these conditions is critical.

Croup, a viral infection, typically presents with a barking cough and inspiratory stridor, while epiglottitis, a bacterial infection, is characterized by sudden-onset fever, drooling, and severe respiratory distress.

Since misdiagnosing these conditions can lead to inappropriate interventions and severe complications, mastering their identification and treatment is essential for safe and effective patient care.

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Croup vs. Epiglottitis: Why Respiratory Therapists Must Know the Difference

When preparing for the TMC and CSE exams, respiratory therapists must be able to differentiate between croup and epiglottitis, two upper airway conditions that can cause life-threatening respiratory distress in children.

While they share some overlapping symptoms, such as stridor and respiratory difficulty, their causes, progression, and treatments differ significantly.

A misdiagnosis could lead to improper treatment and serious complications. Understanding their distinct characteristics will not only help you excel on your exams but also prepare you to manage these critical situations in clinical practice.

Causes and Pathophysiology

Croup (Laryngotracheobronchitis)

Croup is a viral infection that causes inflammation and swelling of the larynx, trachea, and bronchi. The parainfluenza virus is the most common culprit, though other viruses like influenza and respiratory syncytial virus (RSV) can also be responsible.

The swelling leads to airway narrowing, particularly in the subglottic region, causing the characteristic “barking” cough and inspiratory stridor. Symptoms usually develop gradually over a few days, often worsening at night.

Epiglottitis

Epiglottitis, on the other hand, is a bacterial infection that leads to rapid inflammation of the epiglottis, the flap of tissue that covers the trachea during swallowing.

The most common causative agent is Haemophilus influenzae type B (Hib), though Streptococcus and Staphylococcus species can also be responsible. Unlike croup, epiglottitis progresses quickly and can lead to complete airway obstruction within hours if not treated promptly.

Clinical Presentation

Recognizing the key differences in symptoms between croup and epiglottitis is essential for both the TMC/CSE exams and real-world patient care.

While both conditions involve upper airway obstruction, their presentations are distinct:

Croup Symptoms

  • Onset: Gradual, typically over a few days
  • Age Group: Most common in children 6 months to 3 years
  • Fever: Low-grade fever (rarely exceeds 102°F)
  • Cough: Characteristic “barking” or “seal-like” cough
  • Stridor: Present, worsens with agitation or crying
  • Drooling: Absent
  • Voice: Hoarse, weak cry
  • Positioning: Can lie flat; symptoms often improve with cool air or humidity

Epiglottitis Symptoms

  • Onset: Sudden, rapid progression over a few hours
  • Age Group: Typically affects children 2 to 6 years, but can occur in adults
  • Fever: High fever (often >102°F)
  • Cough: Minimal or absent
  • Stridor: Soft or absent due to severe airway obstruction
  • Drooling: Present, due to inability to swallow
  • Voice: Muffled or “hot potato” voice
  • Positioning: Tripod position (leaning forward with hands supporting body) to improve breathing

Diagnosis

Both conditions require careful assessment to avoid misdiagnosis. The NBRC TMC and CSE exams often include questions that test your ability to differentiate between these two conditions based on diagnostic findings:

Croup Diagnosis

  • Neck X-ray (AP View): Shows “steeple sign” due to subglottic narrowing.
  • Pulse Oximetry: Usually normal unless severe.
  • Clinical Observation: Based on symptoms, no invasive testing needed.

Epiglottitis Diagnosis

  • Neck X-ray (Lateral View): Shows “thumb sign,” indicating an enlarged epiglottis.
  • Laryngoscopy (Only in a Controlled Setting!): Shows cherry-red, swollen epiglottis.
  • Blood Cultures: To identify the bacterial pathogen.

Exam Hint: Never attempt to visualize the airway with a tongue depressor in a suspected epiglottitis case—it can trigger complete airway obstruction.

Treatment and Management

Once croup or epiglottitis is diagnosed, immediate and appropriate treatment is crucial. The TMC and CSE exams will test your ability to recognize the correct interventions for each condition:

Croup Treatment

Since croup is viral, treatment focuses on symptom management and reducing airway inflammation. Most cases are mild and can be managed at home, but severe cases may require hospitalization.

  • Mild cases: Supportive care with humidified air (cool mist or steam), hydration, and antipyretics for fever.
  • Moderate to severe cases: Nebulized racemic epinephrine (for moderate to severe stridor) to reduce airway swelling, corticosteroids (e.g., dexamethasone) to decrease inflammation, oxygen therapy for hypoxemia, and hospitalization if signs of increasing respiratory distress.

Epiglottitis Treatment

Epiglottitis is a medical emergency due to the risk of sudden airway obstruction. The priority is securing the airway before respiratory failure occurs.

  • Immediate airway management: Endotracheal intubation (in a controlled setting) to maintain a patent airway. If intubation is not possible, an emergency tracheostomy may be required.
  • Oxygen therapy: Administer humidified O2 if SpO2 is low.
  • IV antibiotics: Ceftriaxone or Cefotaxime to treat the bacterial infection.
  • IV fluids: To maintain hydration, since swallowing is impaired.
  • Close ICU monitoring: Due to risk of rapid deterioration.

Exam Hint: In a suspected epiglottitis case, never delay airway intervention to obtain an X-ray. If severe respiratory distress is present, immediate intubation is the priority before further testing.

Relevance to the TMC and CSE Exams

Understanding the differences between croup and epiglottitis is critical for passing the NBRC exams, as well as for real-world clinical practice.

The TMC exam may test your ability to recognize key clinical signs, diagnostic findings, and initial treatments. The CSE may present you with a case scenario where you must make the correct clinical decisions in a simulated environment.

Key concepts that often appear on the exams include:

  • Recognizing “steeple sign” (croup) vs. “thumb sign” (epiglottitis) on X-rays.
  • Identifying the appropriate treatment (steroids and nebulized epinephrine for croup, immediate intubation and antibiotics for epiglottitis).
  • Understanding the urgency of airway intervention in epiglottitis.
  • Avoiding critical mistakes, such as using a tongue depressor in suspected epiglottitis.

TMC Exam Tips on Croup and Epiglottitis

To succeed on the TMC exam, you need to quickly recognize the differences between croup and epiglottitis and choose the appropriate interventions.

Here are some key tips to help you answer these questions correctly:

1. Differentiate Based on Symptoms

  • Croup: Barking cough, inspiratory stridor, low-grade fever, hoarseness, and a gradual onset.
  • Epiglottitis: No cough, high fever, drooling, muffled voice, and sudden onset with tripod positioning.

Exam Hint: If a child is sitting forward, drooling, and has difficulty breathing but no cough, suspect epiglottitis and prepare for immediate airway intervention.

2. Know the X-ray Findings

  • Croup: “Steeple sign” (subglottic narrowing) on AP neck X-ray.
  • Epiglottitis: “Thumb sign” (swollen epiglottis) on lateral neck X-ray.

Exam Hint: If an exam question asks for a diagnostic test and you suspect epiglottitis, do not pick an X-ray as the first step—the priority is securing the airway first.

3. Choose the Correct Treatment

  • Croup: Treat with racemic epinephrine, corticosteroids (dexamethasone), and humidified oxygen.
  • Epiglottitis: Immediate intubation, IV antibiotics (ceftriaxone or cefotaxime), and humidified oxygen.

Exam Hint: If a question asks about an intervention for epiglottitis, never select “nebulized epinephrine” or “steroids”—these are ineffective and delay urgent airway management.

4. Avoid Common Pitfalls

  • Never attempt to examine the throat with a tongue depressor in suspected epiglottitis—it can trigger complete airway obstruction.
  • Never delay airway management in epiglottitis for additional testing. If the child is in severe distress, intubate first.
  • Do not give antibiotics for croup—it is viral, not bacterial.

Exam Hint: If the question asks about first-line treatment in epiglottitis and one of the options is immediate intubation, this is usually the correct answer.

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CSE Tips on Croup and Epiglottitis

The Clinical Simulation Exam (CSE) assesses your ability to make critical decisions in real-time patient scenarios. Understanding when and how to intervene in croup and epiglottitis cases is essential for success.

1. Choose the Right Initial Assessment

For Croup:

  • History and physical exam.
  • Pulse oximetry.
  • AP neck X-ray (to check for steeple sign).

For Epiglottitis:

  • History and physical exam.
  • Pulse oximetry.
  • Do not request a throat exam with a tongue depressor.
  • Secure the airway before ordering X-rays or lab tests.

2. Prioritize Airway Management

For Croup (Moderate to Severe Cases):

  • Start oxygen therapy.
  • Administer nebulized racemic epinephrine.
  • Give corticosteroids (dexamethasone).
  • Monitor for improvement before considering intubation.

For Epiglottitis:

  • Secure the airway immediately with controlled endotracheal intubation.
  • Prepare for emergency tracheostomy if intubation fails.
  • Once the airway is secured, start IV antibiotics (ceftriaxone or cefotaxime).

3. Recognize When to Escalate Care

For Worsening Croup:

  • If symptoms persist after racemic epinephrine, consider ICU admission.
  • If stridor worsens despite treatment, be prepared for intubation.

For Worsening Epiglottitis:

  • If signs of complete airway obstruction appear, perform an emergency tracheostomy if intubation fails.
  • Move to ICU for continued monitoring.

4. Avoid Critical Mistakes

For Croup:

  • Do not order antibiotics.
  • Do not intubate unless there is severe respiratory distress.

For Epiglottitis:

  • Do not delay airway management for diagnostic tests.
  • Do not attempt to visualize the airway with a tongue depressor.
  • Do not leave the patient lying flat—keep them in a comfortable position.

Final Takeaway

  • Croup is managed with racemic epinephrine, corticosteroids, and supportive care.
  • Epiglottitis requires immediate airway management followed by IV antibiotics.
  • Always prioritize securing the airway in epiglottitis before ordering additional tests.

Final Thoughts

For respiratory therapists preparing for the TMC and CSE exams, mastering the differences between croup and epiglottitis is essential. While both conditions involve upper airway obstruction, their causes, progression, and treatment strategies are dramatically different.

Croup is viral, progresses gradually, and responds well to steroids and epinephrine, whereas epiglottitis is bacterial, develops rapidly, and requires immediate airway management. By understanding these key differences, you can ensure not only exam success but also life-saving interventions in clinical practice.

For more exam preparation tips and resources, be sure to utilize the materials inside our TMC/CSE Bundle, which includes everything you need to earn a passing score.

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John Landry, BS, RRT

Written by:

John Landry, BS, RRT

John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.