Epiglottitis: When a Simple Sore Throat Becomes a Medical Emergency

A 60-year-old man arrived at the emergency department with a severe sore throat, hoarseness, and fever that had progressively worsened over two days.

At first glance, the clinical findings seemed surprisingly benign.

No drooling.

No obvious respiratory distress.

No stridor.

No alarming findings on oral examination.

Yet a lateral neck radiograph revealed a critical clue.

A swollen epiglottis projects like an enlarged thumb.

The classic Thumb Sign.

Within hours, clinicians confirmed acute epiglottitis and admitted the patient to intensive care because airway obstruction can occur suddenly and catastrophically.

This real-world scenario highlights one of the most important lessons in emergency diagnosis:

Patients with epiglottitis may appear stable until they suddenly are not.

Understanding the imaging characteristics of epiglottitis is therefore essential for physicians, radiologists, emergency clinicians, and medical imaging professionals.

What Is Epiglottitis?

Epiglottitis is an acute inflammatory condition involving the epiglottis and surrounding supraglottic structures.

The epiglottis is a leaf-shaped cartilaginous structure that protects the airway during swallowing.

When inflamed, the epiglottis becomes enlarged and edematous, potentially obstructing airflow.

Because the airway diameter in this region is relatively narrow, even modest swelling can become life-threatening.

Why Epiglottitis Is Dangerous

The danger lies not in infection alone but in rapid airway compromise.

Complications include:

Acute respiratory failure
Complete airway obstruction
Hypoxic brain injury
Cardiac arrest
Death

Before widespread vaccination, epiglottitis was one of the most feared pediatric emergencies.

Today, the disease has shifted predominantly toward adults.

Epidemiology

Historical Perspective

Before the introduction of the Hib vaccine, most cases occurred in children aged 2–6 years.

The routine administration of the Haemophilus influenzae type b vaccine dramatically reduced pediatric disease incidence.

Today:

Population	Incidence Trend
Children	Markedly decreased
Adults	Increasing proportion
Elderly	Higher morbidity risk
Immunocompromised patients	Increased susceptibility

The majority of modern cases are diagnosed in adults.

Pathophysiology

The disease begins when pathogens invade supraglottic tissues.

Inflammation triggers:

Vascular dilation
Increased capillary permeability
Tissue edema
Epiglottic enlargement
Progressive airway narrowing

As swelling progresses:

Airway diameter decreases exponentially.

A small increase in tissue thickness may result in a dramatic increase in airflow resistance.

This explains why patients can deteriorate unexpectedly.

Causes of Epiglottitis

Bacterial Causes

Most common organisms include:

Haemophilus influenzae type b
Streptococcus pneumoniae
Streptococcus pyogenes
Staphylococcus aureus

Viral Causes

Influenza
Varicella-zoster virus
Herpes simplex virus

Noninfectious Causes

Thermal injury
Caustic ingestion
Airway trauma
Foreign bodies
Radiation therapy complications

Clinical Presentation

Classic Symptoms

Patients frequently report:

Severe sore throat
Fever
Hoarseness
Odynophagia
Dysphagia

Interestingly, physical examination may appear relatively normal despite severe symptoms.

This mismatch is a classic clue.

Advanced Symptoms

As airway compromise develops:

Drooling
Stridor
Respiratory distress
Tachypnea
Cyanosis
Tripod positioning

These findings indicate imminent airway danger.

Imaging Evaluation of Epiglottitis

Medical imaging plays a central role in diagnosis.

Radiologists often provide the first objective evidence of disease.

Figure 1. Acute Epiglottitis on Lateral Neck X-ray

Radiologic Interpretation:

The lateral neck radiograph demonstrates marked enlargement and edema of the epiglottis, producing the characteristic Thumb Sign.

The swollen epiglottis projects posteriorly into the airway and resembles an enlarged thumb.

This finding is highly suggestive of acute infectious epiglottitis.

Diagnostic Contribution:

The thumb sign remains one of the most recognized radiographic indicators of epiglottitis and may prompt urgent airway evaluation before respiratory deterioration occurs.

The Classic Thumb Sign

The thumb sign results from:

Thickened epiglottis
Soft tissue edema
Enlargement of supraglottic structures

Normal epiglottic thickness:

< 8 mm

Epiglottitis often exceeds this threshold.

CT Imaging Findings

Figure 2. CT Neck non-contrast, Sagittal

A sagittal view of a computed tomography scan of the neck is presented. This exam reveals significant pathology in the supraglottic airway, marked by a red box for emphasis.

There is marked swelling of the epiglottis, which appears globular and enlarged. This prominent, rounded morphology is characteristic of the "thumb sign" typically described on lateral radiographs but is well-demonstrated here in the CT sagittal reconstruction. The adjacent aryepiglottic folds are also thickened, contributing to the soft tissue redundancy.

Consequently, there is a significant narrowing of the oropharyngeal and supraglottic airway space, placing the patient at high risk for acute airway obstruction. The underlying laryngeal ventricles and vocal cords are partially visible but difficult to fully evaluate due to the overlying edema.

No clear ring-enhancing fluid collection is visible on this non-contrast image to definitively diagnose an epiglottic abscess, though diffuse cellulitis is evident. The thyroid gland appears grossly within normal limits for this view, and the cervical vertebral column and spinal canal show no gross acute abnormalities. A dental restoration creates some streak artifact near the tongue base.

Impression:

CT findings are highly suggestive of acute epiglottitis, demonstrated by marked globoid swelling of the epiglottis and aryepiglottic folds.
Resultant critical narrowing of the supraglottic airway space.

Recommendation: Immediate clinical management and airway stabilization are indicated. Consideration should be given to a contrast-enhanced study if an abscess is suspected, provided the patient is airway-stable.

Why CT Scan Diagnosis Matters

CT imaging helps determine:

Extent of infection
Presence of an abscess
Airway narrowing severity
Surgical planning needs

This is particularly valuable in adult patients whose symptoms may be atypical.

MRI Findings

MRI is rarely required in emergency diagnosis.

Potential findings include:

T2 hyperintense edema
Soft tissue enhancement
Abscess characterization

MRI is mainly reserved for complicated infections.

Differential Diagnosis

Several disorders may mimic epiglottitis.

Disease	Key Imaging Feature
Retropharyngeal abscess	Posterior pharyngeal fluid collection
Peritonsillar abscess	Tonsillar asymmetry
Croup	Steeple sign
Angioedema	Diffuse soft tissue swelling
Supraglottic carcinoma	Mass lesion
Foreign body	Direct visualization

Accurate radiology interpretation is essential to avoid misdiagnosis.

Diagnostic Workflow

Step 1: Clinical Suspicion

Red flags include:

Severe sore throat
Minimal oropharyngeal findings
Hoarseness
Fever

Step 2: Airway Assessment

Evaluate:

Oxygen saturation
Respiratory effort
Stridor

Step 3: Imaging

Preferred modalities:

Lateral neck X-ray
CT neck with contrast

Step 4: Fiberoptic Laryngoscopy

Gold standard visualization method.

Typically reveals:

Cherry-red epiglottis
Marked swelling
Purulent exudate

Step 5: Microbiologic Testing

Includes:

Blood cultures
Airway cultures

Notably, the presented case had negative blood cultures.

Treatment Strategies

Airway Management

Primary priority.

Patients with:

Stridor
Respiratory distress
Rapid progression

may require:

Endotracheal intubation
Emergency tracheostomy

Antibiotic Therapy

Empiric coverage typically includes:

Ceftriaxone
Cefotaxime
Ampicillin-sulbactam

Additional anti-staphylococcal coverage may be necessary.

Intensive Care Monitoring

Many patients require ICU observation.

The uploaded patient was admitted to intensive care due to the risk of airway compromise.

Corticosteroids

Potential benefits:

Reduced edema
Faster symptom improvement

Evidence remains mixed.

Prognosis

With prompt recognition:

Survival exceeds 95%
Most patients recover fully

Poor prognostic factors include:

Delayed diagnosis
Advanced age
Airway compromise
Immunosuppression

The presented patient improved with intravenous antibiotics and completed oral therapy after discharge.

Radiology Pearls for Medical Imaging Professionals

Key Imaging Clues

✓ Thumb Sign

✓ Thickened epiglottis

✓ Aryepiglottic fold edema

✓ Airway narrowing

✓ Supraglottic soft tissue swelling

High-Risk Findings

✓ Abscess formation

✓ Near-complete airway obstruction

✓ Extensive supraglottic edema

Summary Table

Feature	Epiglottitis
Emergency?	Yes
Imaging Modality	X-ray, CT
Classic Sign	Thumb Sign
Common Organism	Hib historically
Airway Risk	Very High
ICU Admission	Often required
Prognosis	Excellent with treatment

Quiz

Question 1. Which radiographic sign is classically associated with epiglottitis?

A. Steeple sign

B. Silhouette sign

C. Thumb sign

D. Air crescent sign

E. Halo sign

Correct Answer: C. Thumb sign. Explanation: The thumb sign reflects enlargement and edema of the epiglottis on lateral neck radiography.

Question 2. Which imaging modality best evaluates abscess formation in adult epiglottitis?

A. Ultrasound

B. Mammography

C. CT with contrast

D. Bone scan

E. Fluoroscopy

Correct Answer: C. CT with contrast. Explanation: Contrast-enhanced CT provides excellent assessment of soft tissue infection, abscesses, and airway narrowing.

Question 3. What is the most immediate concern in acute epiglottitis?

A. Pneumonia

B. Sepsis

C. Vocal cord paralysis

D. Airway obstruction

E. Pleural effusion

Correct Answer: D. Airway obstruction. Explanation: Airway compromise is the primary cause of morbidity and mortality.

Key Takeaways

Epiglottitis is a life-threatening airway emergency.
Adults now account for most cases.
A severe sore throat with a normal oral examination should raise suspicion.
The Thumb Sign remains a classic radiographic finding.
CT scan diagnosis is critical for assessing disease extent and abscess formation.
Airway management is the first treatment priority.
Early recognition dramatically improves outcomes.

Frequently Asked Questions (FAQ)

Can adults get epiglottitis?

Yes. Since Hib vaccination became widespread, most modern cases occur in adults.

Is CT better than X-ray?

CT provides superior anatomical detail and identifies complications such as abscess formation.

What is the thumb sign?

A swollen epiglottis is seen on lateral neck radiography, resembling a thumb.

Can epiglottitis be fatal?

Yes. Untreated disease can rapidly progress to complete airway obstruction.

How long does recovery take?

Most patients improve within several days after antibiotic therapy and airway stabilization.

Epiglottitis: The Hidden Airway Emergency Every Clinician Must Recognize