Infectious Diseases in Children

Table 1 Croup severity classification^a

Item	Mild	Moderate	Severe
General behavior	Normal	Mild intermittent agitation	Drowsiness or severe agitation
Presence of stridor	Only with irritation or activity	Intermittent at rest	Continuous at rest
Signs of respiratory distress	None	Mild increase of accessory muscles, nasal flaring, and increased respiratory rate	Marked use of accessory muscles of respiration Increased or decreased respiratory rate (muscle fatigue)
Hypoxemia			Very late and serious sign indicates life threatening airway obstruction