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Emergency And Acute Medicine – Croup
Description
Croup is a viral infection of the upper respiratory tract that most commonly affects children between 6 months and 3 years of age. It typically presents as laryngotracheitis or laryngotracheobronchitis with inspiratory stridor caused by extrathoracic airway obstruction. Expiratory wheezing suggests lower airway involvement. The disease results from inflammatory edema of the subglottic region, the narrowest portion of the pediatric airway, and may progress to respiratory failure in severe cases.
Etiology
The most common causative organisms are parainfluenza virus types 1, 2, and 3. Other causes include human coronavirus NL63, influenza A and B, adenovirus, respiratory syncytial virus, measles, Mycoplasma pneumoniae, and herpes simplex virus.
Clinical Presentation
Children usually develop a nonspecific upper respiratory prodrome with or without fever. Important historical features include duration of illness, prior tracheal intubation, risk of foreign body aspiration, previous episodes of croup, history of wheezing, and immunization status, particularly against Haemophilus influenzae type b, diphtheria, pertussis, tetanus, and influenza.
On examination, children are often not toxic appearing and typically prefer to sit upright. Cyanosis is uncommon and suggests severe disease when present. Clinicians should assess the quality of cry or voice, mental status, hydration, presence of drooling or trismus, neck mobility, stridor at rest, and work of breathing.
Severity can be graded using the Westley croup score, which incorporates stridor, retractions, air entry, cyanosis, and level of consciousness.
Diagnostic Evaluation
Continuous pulse oximetry is recommended. Routine laboratory testing is not indicated. Imaging is generally unnecessary but, when obtained for atypical presentations, anteroposterior and lateral neck radiographs may show the classic “steeple sign” reflecting subglottic narrowing. Imaging should never delay airway management in patients with suspected epiglottitis or bacterial tracheitis, and children must be closely monitored if imaging is performed.
Differential Diagnosis
Infectious causes include bacterial tracheitis, epiglottitis, retropharyngeal or parapharyngeal abscess, peritonsillar abscess, and diphtheria. Noninfectious causes include foreign body aspiration, angioedema, congenital airway abnormalities such as laryngomalacia or tracheomalacia, acquired subglottic stenosis, vocal cord paralysis, airway burns, hemangioma, laryngeal papillomatosis, and vocal cord dysfunction in adolescents.
Initial Management
Children should be allowed to maintain their position of comfort, and interventions that may increase distress, such as IV access or intramuscular injections, should be deferred when possible. In cases of severe respiratory distress, immediate nebulized epinephrine should be administered.
Emergency Department Management
Nebulized racemic epinephrine or L-epinephrine is indicated for stridor at rest or significant respiratory distress and is effective in reducing airway edema. Supplemental oxygen may be provided via blow-by if hypoxia is suspected. Dexamethasone significantly improves outcomes by reducing the need for intubation, hospital admission, and return visits, and is effective even in mild cases. If there is an incomplete response to epinephrine, heliox may be considered to reduce work of breathing.
For patients with impending or established respiratory failure, tracheal intubation should be performed by the most experienced provider available using an uncuffed endotracheal tube 0.5–1 mm smaller than standard size. If epiglottitis or foreign body aspiration is suspected, airway management should ideally occur in the operating room with surgical backup available.
Medications
Racemic epinephrine 2.25% is administered as 0.25–0.5 mL nebulized in normal saline. L-epinephrine 1:1,000 may be given as 5 mL nebulized. Dexamethasone is given as a single dose of 0.6 mg/kg, up to a maximum of 10 mg, via oral, intravenous, or intramuscular routes. Heliox may be administered as a 70:30 helium–oxygen mixture. Antibiotics are not indicated.
Disposition And Follow-Up
Hospital admission is recommended for young infants, children with pre-existing airway disease, persistent or recurrent stridor at rest despite treatment, or those requiring repeated epinephrine treatments. Pediatric intensive care admission is indicated for severe obstruction, frequent need for epinephrine or heliox, or need for intubation.
Children may be discharged if they have normal oxygenation on room air, no stridor at rest after observation for at least 2–3 hours, and reliable caregivers with access to follow-up care.
Referral Considerations
Evaluation by specialists is warranted for children with suspected anatomic airway abnormalities, recurrent episodes, prior intubation, or infants younger than one year with unexplained stridor.
Follow-Up Guidance
Most children with uncomplicated croup do not require routine follow-up. Caregivers should be instructed to seek medical attention if stridor persists, worsens, or recurs.
Key Teaching Points And Common Errors
Stridor in young infants warrants careful evaluation due to a higher likelihood of congenital airway abnormalities. Early epiglottitis or bacterial tracheitis may closely mimic croup and should be considered when symptoms are atypical or severe.
Description
Croup is a viral infection of the upper respiratory tract that most commonly affects children between 6 months and 3 years of age. It typically presents as laryngotracheitis or laryngotracheobronchitis with inspiratory stridor caused by extrathoracic airway obstruction. Expiratory wheezing suggests lower airway involvement. The disease results from inflammatory edema of the subglottic region, the narrowest portion of the pediatric airway, and may progress to respiratory failure in severe cases.
Etiology
The most common causative organisms are parainfluenza virus types 1, 2, and 3. Other causes include human coronavirus NL63, influenza A and B, adenovirus, respiratory syncytial virus, measles, Mycoplasma pneumoniae, and herpes simplex virus.
Clinical Presentation
Children usually develop a nonspecific upper respiratory prodrome with or without fever. Important historical features include duration of illness, prior tracheal intubation, risk of foreign body aspiration, previous episodes of croup, history of wheezing, and immunization status, particularly against Haemophilus influenzae type b, diphtheria, pertussis, tetanus, and influenza.
On examination, children are often not toxic appearing and typically prefer to sit upright. Cyanosis is uncommon and suggests severe disease when present. Clinicians should assess the quality of cry or voice, mental status, hydration, presence of drooling or trismus, neck mobility, stridor at rest, and work of breathing.
Severity can be graded using the Westley croup score, which incorporates stridor, retractions, air entry, cyanosis, and level of consciousness.
Diagnostic Evaluation
Continuous pulse oximetry is recommended. Routine laboratory testing is not indicated. Imaging is generally unnecessary but, when obtained for atypical presentations, anteroposterior and lateral neck radiographs may show the classic “steeple sign” reflecting subglottic narrowing. Imaging should never delay airway management in patients with suspected epiglottitis or bacterial tracheitis, and children must be closely monitored if imaging is performed.
Differential Diagnosis
Infectious causes include bacterial tracheitis, epiglottitis, retropharyngeal or parapharyngeal abscess, peritonsillar abscess, and diphtheria. Noninfectious causes include foreign body aspiration, angioedema, congenital airway abnormalities such as laryngomalacia or tracheomalacia, acquired subglottic stenosis, vocal cord paralysis, airway burns, hemangioma, laryngeal papillomatosis, and vocal cord dysfunction in adolescents.
Initial Management
Children should be allowed to maintain their position of comfort, and interventions that may increase distress, such as IV access or intramuscular injections, should be deferred when possible. In cases of severe respiratory distress, immediate nebulized epinephrine should be administered.
Emergency Department Management
Nebulized racemic epinephrine or L-epinephrine is indicated for stridor at rest or significant respiratory distress and is effective in reducing airway edema. Supplemental oxygen may be provided via blow-by if hypoxia is suspected. Dexamethasone significantly improves outcomes by reducing the need for intubation, hospital admission, and return visits, and is effective even in mild cases. If there is an incomplete response to epinephrine, heliox may be considered to reduce work of breathing.
For patients with impending or established respiratory failure, tracheal intubation should be performed by the most experienced provider available using an uncuffed endotracheal tube 0.5–1 mm smaller than standard size. If epiglottitis or foreign body aspiration is suspected, airway management should ideally occur in the operating room with surgical backup available.
Medications
Racemic epinephrine 2.25% is administered as 0.25–0.5 mL nebulized in normal saline. L-epinephrine 1:1,000 may be given as 5 mL nebulized. Dexamethasone is given as a single dose of 0.6 mg/kg, up to a maximum of 10 mg, via oral, intravenous, or intramuscular routes. Heliox may be administered as a 70:30 helium–oxygen mixture. Antibiotics are not indicated.
Disposition And Follow-Up
Hospital admission is recommended for young infants, children with pre-existing airway disease, persistent or recurrent stridor at rest despite treatment, or those requiring repeated epinephrine treatments. Pediatric intensive care admission is indicated for severe obstruction, frequent need for epinephrine or heliox, or need for intubation.
Children may be discharged if they have normal oxygenation on room air, no stridor at rest after observation for at least 2–3 hours, and reliable caregivers with access to follow-up care.
Referral Considerations
Evaluation by specialists is warranted for children with suspected anatomic airway abnormalities, recurrent episodes, prior intubation, or infants younger than one year with unexplained stridor.
Follow-Up Guidance
Most children with uncomplicated croup do not require routine follow-up. Caregivers should be instructed to seek medical attention if stridor persists, worsens, or recurs.
Key Teaching Points And Common Errors
Stridor in young infants warrants careful evaluation due to a higher likelihood of congenital airway abnormalities. Early epiglottitis or bacterial tracheitis may closely mimic croup and should be considered when symptoms are atypical or severe.
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