Croup is a respiratory illness characterized by inspiratory stridor, cough, and hoarseness. These symptoms result from inflammation in the larynx and subglottic airway. A barking cough is the hallmark of croup among infants and young children, whereas hoarseness predominates in older children and adults. Although croup usually is a mild and self-limited illness, significant upper airway obstruction, respiratory distress, and, rarely, death, can occur.
The clinical features, evaluation, and diagnosis of croup will be discussed here. The management of croup is discussed separately. (See "Croup: Approach to management" and "Croup: Pharmacologic and supportive interventions".)
The term croup has been used to describe a variety of upper respiratory conditions in children, including laryngitis, laryngotracheitis, laryngotracheobronchitis, bacterial tracheitis, or spasmodic croup . These terms are defined below. In the past, the term croup also has been applied to laryngeal diphtheria (diphtheritic or membranous croup), which is discussed separately. (See "Epidemiology and pathophysiology of diphtheria" and "Clinical manifestations, diagnosis and treatment of diphtheria".)
Throughout this review, the term croup will be used to refer to laryngotracheitis. Laryngotracheobronchitis, laryngotracheobronchopneumonitis, bacterial tracheitis, and spasmodic croup are designated specifically as such.
●Laryngitis refers to inflammation limited to the larynx and manifests itself as hoarseness . It usually occurs in older children and adults and, similar to croup, is frequently caused by a viral infection. The etiology, management, and evaluation of other causes of hoarseness are discussed in detail separately. (See "Hoarseness in children: Etiology and management" and "Hoarseness in children: Evaluation".)