Note: OP Ghai 10th Edition is not available in the digital textbook library. The content below is synthesized from authoritative pediatric and ENT references (Rosen's Emergency Medicine, Cummings Otolaryngology, Harriet Lane Handbook) to match OP Ghai's coverage and Indian exam focus, supplemented with standard OP Ghai teaching points well-established in the literature.

CROUP (Acute Laryngotracheobronchitis - LTB)

Definition

Mnemonic 1: CROUP - Basic Overview

Children 6 months-3 years Rooster/seal-like barky cough Obstruction at subglottis Upper airway (larynx + trachea) Parainfluenza virus (most common - types 1, 2, 3)

Etiology

• Season: Late autumn and winter (peak October-November)
• Age: 6 months to 3 years (most cases <3 years); rare after 6 years
• Sex: Boys > Girls (1.4:1)
• Incubation: 2-6 days

Pathophysiology

Subglottic edema (primary site) Infection spreads nasopharynx → larynx → trachea Rigid cricoid ring (only complete cartilaginous ring) - cannot expand Exudates + mucosal inflammation narrow lumen Narrowing to 1-2 mm in severe cases

Clinical Features

Prodrome (1-3 days):

• Mild fever, coryza, runny nose (viral URI symptoms)

Classic Triad - Mnemonic: "HBS"

Hoarseness (voice) Barky/Brassy cough (seal-like, "croupy") Stridor (inspiratory, high-pitched)

Additional features:

• Symptoms worse at night
• Child typically not toxic in appearance (unlike epiglottitis)
• Symptoms usually resolve in 4-7 days (80% resolve within 2 days)
• Tachycardia, tachypnea in moderate-severe cases

Severity Grading (Westley Score)

Mnemonic: "SCARE" (5 parameters)

Stridor Cyanosis Air entry (decreased) Retractions Extra work - consciousness level

Important: Decreasing stridor with worsening distress = impending respiratory failure (not improvement!)

Diagnosis

Clinical Diagnosis - Mnemonic: "BASH"

Barky cough Age 6 months-3 years Stridor (inspiratory) Hoarseness

X-ray Finding:

• AP view neck/chest: "Steeple sign" (church steeple/pencil sign) - subglottic narrowing
• Present in only 50% of cases - absence does NOT rule out croup
• Lateral view: Hypopharyngeal dilation above narrowed subglottis

Mnemonic for X-ray: "Croup = Church Steeple" (pointed narrowing on AP view)

Differential Diagnosis - Mnemonic: "BEEFAR"

Bacterial tracheitis (toxic, high fever, no response to treatment) Epiglottitis (toxic, drooling, tripod position, no cough, muffled voice) Extrinsic compression (vascular ring, lymph nodes) Foreign body aspiration (no URI, sudden onset, choking history) Anaphylaxis (acute, trigger history, urticaria) Retropharyngeal abscess (fever, torticollis, neck stiffness)

Croup vs. Epiglottitis - Key Differences:

Mnemonic for Epiglottitis features: "4 D's" - Dysphagia, Drooling, Distress, Dysphonia (muffled)

Management

Mnemonic: "CROUP Treatment"

Comfort the child (minimize agitation!) Racemic epinephrine nebulization (moderate-severe) Oxygen (if SpO2 <94%) Upright/comfortable position P - dexamethasone (steroid)

Step-by-Step Management:

All patients:

• Minimize agitation (crying worsens obstruction)
• Comfortable position (parent's lap preferred)
• Mist therapy (cool humidified air) - traditionally used; current evidence limited
• Antipyretics + oral hydration

Mild Croup:

• Oral Dexamethasone: 0.15-0.6 mg/kg (single dose, max 16 mg) - drug of choice
• Discharge with instructions

Moderate Croup:

• Dexamethasone 0.6 mg/kg oral/IM (single dose)
• Nebulized budesonide 2 mg if unable to take oral
• Nebulized epinephrine (racemic 2.25% solution, 0.5 mL in 2.5 mL NS) or L-epinephrine (5 mL of 1:1000)
• Observe for minimum 2-3 hours after epinephrine (rebound phenomenon possible at 2 hours)

Severe Croup:

• Nebulized epinephrine + Dexamethasone (IV/IM)
• Heliox (helium-oxygen 70:30) - reduces work of breathing
• ICU admission
• Intubation if necessary (use tube 0.5-1 mm smaller than calculated)
• Oxygen supplementation

Drug Summary - Mnemonic: "DEB"

Dexamethasone - steroid of choice (oral preferred) Epinephrine - nebulized (racemic or L-epi) Budesonide - alternative inhaled steroid

Indications for Hospital Admission

Mnemonic: "SHARP"

Stridor at rest despite treatment Hypoxia or cyanosis Abnormal mental status / altered sensorium Respiratory distress (severe retractions) Poor oral intake / dehydration OR persistent tachycardia/tachypnea

Spasmodic Croup

• Recurrent, atypical croup
• Associated with allergy, atopy, GERD, airway hyper-reactivity
• No viral prodrome
• Sudden onset, typically at night, resolves quickly
• Responds well to cool air/mist, steroids

Complications (Rare)

• Respiratory failure
• Bacterial superinfection (bacterial tracheitis) - caused by S. aureus or H. influenzae
• Subglottic stenosis (post-intubation)
• Pulmonary edema (post-obstruction)

Key Points for Exam (OP Ghai Focus)

Master Mnemonic Summary

"PARA CROUP" - Remember Everything

Parainfluenza (most common cause) Age 6 months - 3 years Retractions + Respiratory distress AP X-ray = Steeple sign

Coryza prodrome 1-3 days Rooster/seal barky cough Obstruction at subglottis Upright position + minimize crying Peak severity at night