Pulmonology Book


CroupAka: Laryngo-tracheo Bronchitis, Laryngotracheal Bronchitis, Laryngotracheitis, Laryngotracheobronchitis, Spasmodic Croup


  1. History
    1. Word "Croup" derived from Scottish for raven's "croak"
  2. Epidemiology
    1. Incidence
      1. Overall Incidence: 6 cases per 100 children <6 years
      2. Hospitalizations: 1-15% of US cases (20,000 per year)
      3. Intubation: 1-5% of cases hospitalized
    2. Boys affected more than girls by ratio of 1.5 to 1
    3. Outbreaks and epidemics occur in autumn to early winter
    4. Affects ages under 12 years (peaks at age 1-2 years)
  3. Pathophysiology
    1. Subglottic infection
  4. Etiology
    1. Parainfluenza virus type 1 (18% of cases)
    2. Parainfluenza virus types 3, 2
    3. Adenovirus
    4. Respiratory Syncytial Virus (RSV)
    5. Influenza A and Influenza B
    6. Rhinovirus
    7. Enteroviruses
    8. Mycoplasma pneumoniae (uncommon)
  5. Symptoms
    1. Fever
    2. Coryza precedes other symptoms by several days
    3. Upper respiratory symptoms rapidly develop
      1. Hoarseness
      2. Cough: "Barking" OR "seal-like"
      3. Inspiratory Stridor
      4. Expiratory Wheezing
      5. Dyspnea
    4. Symptoms worse at night
    5. Symptom duration <1 week (peaks at 1-2 days)
  6. Signs
    1. "Sound worse than they look" (Opposite of Epiglottitis)
    2. Mild to Moderate respiratory distress
    3. Mild Wheezes
  7. Labs
    1. Complete Blood Count with mild Leukocytosis
  8. Diagnosis
    1. See Croup Score
  9. Differential Diagnosis (Croup is diagnosis of exclusion)
    1. Epiglottitis
    2. Bacterial Tracheitis
    3. Ludwig's Angina
    4. Peritonsillar Abscess
    5. Diphtheria
    6. Paraquat Poisoning (Herbicides)
    7. Foreign-body obstruction
      1. History of Choking episode (88%)
      2. Neck XRay PA and Lateral if object is radiopaque
  10. Radiology: Neck XRay
    1. Subglottic Narrowing
    2. "Steeple" sign on PA Neck XRay (40-50% of croup cases)
    3. Narrowing of subglottic region from mucosal edema
    4. Images
      1. RadCroupMedPix1246.jpg
  11. Management: Home Therapy
    1. Maintain adequate Ambient humidity in house
    2. Cool mist may decrease subglottic edema
      1. No studies to support this
      2. May make Asthma worse due to irritation
      3. Options
        1. Cool-mist humidifier
        2. Cold weather
          1. Bundle child warmly
          2. bring outside for 15 minutes
        3. Closed bathroom with cold shower mist
    3. Maintain adequate hydration
      1. Offer child favorite drink every 10 minutes
      2. Consider crushed ice drinks or other frozen treats
    4. Corticosteroids
      1. See Dexamethasone in Croup
  12. Management: Emergency Department and Inpatient
    1. Humidified Oxygen
    2. Nebulized racemic epinephrine
    3. Corticosteroids
      1. See Dexamethasone in Croup
    4. Antibiotics
      1. Not indicated unless concurrent bacterial infection
    5. Helium added to Oxygen
      1. May prevent intubation in borderline patients
    6. Intubation
      1. Indicated less frequently now with above management
      2. Significant risk of subglottic stenosis
      3. Use ET Tube at least 1 size smaller than predicted
  13. Outpatient Management Indications
    1. Non-toxic appearance
    2. Well hydrated and taking oral fluids
    3. Minimal or no Stridor or retractions at rest
      1. At presentation or 2 hours after Epinephrine
    4. Reliable parents
  14. Inpatient Observation Indications
    1. Signs of respiratory distress or respiratory failure
    2. Cyanosis
    3. Tachypnea
    4. Agitation or Fatigue
    5. Stridor severity
    6. Accessory muscle use
      1. Intercostal retractions
      2. Neck or abdominal muscle use
    7. Rising arterial PCO2
  15. References
    1. Folland (1997) J Postgrad Med 101(3):271
    2. Geelhoed (1997) Pediatr Pulmonol 23:370
    3. Klassen (1994) N Engl J Med 331:285
    4. Knutson (2004) Am Fam Physician 69(3):535
    5. Quan (1992) Am Fam Physician 46(3):747

Croup (C0010380)

Definition (MSH)A condition characterized by resonant barking cough, hoarseness and persistant stridor and caused by allergy, foreign body, infection, or neoplasm. It occurs chiefly in infants and children.
ConceptsDisease or Syndrome (T047)
ICD9464.4, 464.4
EnglishAcute laryngotracheobronchitis, Acute Obstructive Laryngitis, Croup, Croup syndrome
Spanishcrup, crup laringeo, sindrome crupal
Parent ConceptsOther upper respiratory infections (C0810016), Acute laryngitis and/or tracheitis (C0155811), Laryngitis (C0023067), Acute laryngitis NOS (C0001327), Laryngotracheobronchitis (C0023077), Acute bronchitis (C0149514), Acute tracheobronchitis (C0264321), Duplicate concept (C1274013)
Derived from the NIH UMLS (Unified Medical Language System)

Laryngotracheitis (C0023076)

ConceptsDisease or Syndrome (T047)
EnglishLaryngotracheitis, Tracheitis with laryngitis
Parent ConceptsLaryngitis (C0023067), Tracheitis (C0040584), Duplicate concept (C1274013)
Derived from the NIH UMLS (Unified Medical Language System)

Laryngotracheobronchitis (C0023077)

ConceptsDisease or Syndrome (T047)
EnglishLaryngotracheobronchitis, LTB - Laryngotracheobronchitis
Spanishfalso crup, laringotraqueobronquitis
Parent ConceptsBronchitis (C0006277), Laryngotracheitis (C0023076), Tracheobronchitis NOS (C0040586), Duplicate concept (C1274013)
Derived from the NIH UMLS (Unified Medical Language System)

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