Croup Clinical Presentation

Croup usually begins with nonspecific respiratory symptoms, including rhinorrhea, sore throat, and cough. Fever is generally low grade (38-39°C) but can exceed 40°C. Within 1-2 days, the characteristic signs of hoarseness, barking cough, and inspiratory stridor develop, often suddenly, along with a variable degree of respiratory distress. Symptoms are perceived as worsening at night, with most ED visits occurring between 10 pm and 4 am. Symptoms typically resolve within 3-7 days but can last as long as 2 weeks.

Spasmodic croup typically presents at night with the sudden onset of "croupy" cough and stridor. The child may have had mild upper respiratory complaints prior to this but more often has acted and appeared completely well prior to the onset of symptoms.

The physical presentation of croup widely varies. Most children have no more than a "croupy" cough and hoarse cry. Some may have stridor only upon activity or agitation, whereas others have audible stridor at rest and evidence of respiratory distress. Paradoxically, the severely affected child may have "quiet" stridor secondary to the degree of airway obstruction. The child with croup typically does not appear toxic.

The child's symptoms range from minimal inspiratory stridor to severe respiratory failure secondary to airway obstruction.^[8] In mild cases, respiratory sounds at rest are normal; however, mild expiratory wheezing may be heard. Children with more severe cases have inspiratory and expiratory stridor at rest with suprasternal, intercostal, and subcostal retractions. Air entry may be poor. Lethargy and agitation may be due to hypoxemia.

Other warning signs of severe respiratory disease include tachypnea, tachycardia out of proportion to fever, and hypotonia. Children may be unable to maintain adequate oral intake, which results in compromised hydration and leads to dehydration. Cyanosis is a late, ominous sign.

Scoring systems

Croup scores have been developed to assist the clinician in assessing the degree of respiratory compromise. One of the most commonly cited is the Westley score. Although widely used to evaluate treatment protocols, its clinical efficacy has not been extensively studied. The score evaluates the severity of croup by assessing the following 5 factors, with a score range of 0 to 17:

• Inspiratory stridor: None - 0 points, Upon agitation - 1 point, At rest - 2 points
• Retractions: None - 0 points, Mild - 1 point, Moderate - 2 points, Severe - 3 points
• Air entry: Normal - 0 points, Mild decrease - 1 point, Marked decrease - 2 points
• Cyanosis: None - 0 points, Upon agitation - 4 points, At rest - 5 points
• Level of consciousness: Normal, including sleep - 0 points, Depressed - 5 points

According to the Westley score, a score of less than 3 represents mild disease; a score of 3-6 represents moderate disease; and a score greater than 6 represents severe disease.

Mild disease consists of occasional barking cough, no stridor at rest, and mild or nonexistent suprasternal or subcostal retractions. Moderate disease includes frequent cough, audible stridor at rest, and visible retractions, but little distress or agitation. Severe disease consists of frequent cough, prominent inspiratory (and, occasionally, expiratory) stridor, conspicuous retractions, decreased air entry on auscultation, and significant distress and agitation. Lethargy, cyanosis, and decreasing retractions are harbingers of impending respiratory failure.

Another clinically useful severity assessment table has been developed by the Alberta Clinical Practice Guideline Working Group.^[9] Using this classification scheme, 85% of children in 21 general emergency departments in Alberta, Canada, were determined to have mild croup, and less than 1% had severe croup. The assessment is as follows:

• Mild severity - Occasional barking cough, no audible stridor at rest, and either no or mild suprasternal and/or intercostal retractions
• Moderate severity - Frequent barking cough, easily audible stridor at rest, and suprasternal and sternal wall retractions at rest, with no or minimal agitation
• Severe severity - Frequent barking cough, prominent inspiratory (and occasionally expiratory) stridor, marked sternal wall retractions, significant agitation and distress
• Impending respiratory failure - Barking cough (often not prominent), audible stridor at rest, sternal wall retractions may not be marked, lethargy or decreased consciousness, and often dusky appearance without supplemental oxygen support

As part of these clinical practice guidelines, recommendations for medical interventions and care are presented in an algorithm based on the severity of the patient’s initial symptoms.