33. Inflammatory diseases of the larynx - subchordal laryngitis, epiglottitis.

Inflammatory diseases of the larynx – subchordal laryngitis, epiglottitis.

1. Subchordal Laryngitis - Acute Laryngotracheobronchitis, this involves inflammation and edema of the subglottic region

1. Definition: An acute viral infection causing inflammation and narrowing of the subglottic airway, primarily affecting children aged 6 months to 3 years. Below vocal cords. Leading to airway narrowing.

2. Etiopathogenesis

• Pathogens: Mostly viral. Parainfluenza virus (Type 1 & 3) is the most common. include Adenovirus, RSV, and Influenza.
• Predisposing Factors: Age 6 months–6 years, Cold climate, Allergies, Passive smoking
• Mechanism: Viral infection → mucosal inflammation → narrowing of the subglottic airway
• Children have a naturally narrow subglottic space → small edema causes large airway obstruction
• Leads to inspiratory stridor, barking cough

3. Classification - Westley Croup Score

1. 1. Mild: Occasional barking cough, no stridor at rest
2. 2. Moderate: Stridor at rest, mild retractions
3. 3. Severe: Marked retractions, agitation, fatigue
4. 4. Impending respiratory failure: Lethargy, cyanosis, severe hypoxia

4. Clinical Picture

• Prodrome: 1–3 days of coryza (runny nose) and low-grade fever.
• Classic Triad: 1. Barking cough (seal-like). 2. Inspiratory stridor. 3. Hoarseness.
• Symptoms often worsen at night.
• Signs of distress: cyanosis, dyspnoea, Suprasternal and intercostal retractions.

5. Paraclinical & Radiological Examinations

• Diagnosis: Primarily clinical.
• Radiology: X-ray of the neck (AP view) shows the "Steeple Sign" — a subglottic narrowing of the tracheal air column.

6. Treatment Options

1. 1. Mild: Humidified air/cool mist (historical, although evidence is limited) and hydration.
2. 2. Moderate/Severe: Corticosteroids: Dexamethasone (oral or IM) is the gold standard.

• Nebulized Epinephrine: Provides rapid, temporary vasoconstriction to reduce edema.

1. 3. Oxygen: If saturations are low.

7. Complications & Differential Diagnosis

• Complications: Bacterial tracheitis (secondary infection), pneumonia, or respiratory failure.
• Differential: Foreign body aspiration, subglottic stenosis, or epiglottitis.

2. Acute Epiglottitis (Supraglottitis) - This is a medical emergency involving the structures above the vocal cords.

1. Definition: Acute epiglottitis is a rapidly progressing inflammation of the epiglottis and supraglottic structures, causing sudden airway obstruction.

2. Etiopathogenesis

• Pathogens: Historically Haemophilus influenzae type b (Hib). Due to vaccination, it is now rare in children but seen in adults. Other causes: Streptococcus pyogenes, S. pneumoniae, and S. aureus.
• Non-infectious: Thermal burns (hot liquids/steam), chemical burns.
• Pathophysiology:
• Infection → rapid edema of epiglottis
• Obstruction of supraglottic airway
• Patient compensates by leaning forward (tripod position)

3. Clinical Picture (The "4 Ds")

1. 1. Drooling: Due to severe odynophagia (painful swallowing).
2. 2. Dysphagia: Difficulty swallowing.
3. 3. Dysphonia: Muffled "hot potato" voice (not hoarse like croup).
4. 4. Distress: Rapidly progressive respiratory obstruction.