investigation

Last reviewed 10/2022

• investigation is probably indicated if a child has suffered a number of episodes of croup, and is especially indicated if the child was preterm
• investigations in the acute presentation may include:
  • plain neck radiography (1)
    • the steeple sign (1)
      • posterior-anterior view - shows a narrowed column of subglottic air
      • lateral view -shows an overdistended hypopharynx
      • this sign is seen only in 50 percent of patients
  • computed tomography (1)
  • pulse oximetry (1)
• in recurrent croup
  • bronchoscopy - probably best by a paediatric chest physician rather than an ENT surgeon since the paediatrician will investigate below the vocal cords

Reference:

• (1) Doug Knutson, Viral Croup, Am Fam Physician, 2004;69:535-40,541-2