Imaging: normal prevertebral space is < 1/2 vertebral body at C2, soft tissue thickening of > 1 cervical vertebral body, to diagnose retropharyngeal mass need inspiratory image taken in extension, measurements less important than whether retropharynx changes with respiration, always check for airway compression / jugular vein occlusion / extension into mediastinum
DDX: physiological tracheal buckling which can be seen on lateral neck images obtained on expiration + flexion – so beware of false positives due to expiration / flexion – airway radiograph should always be taken in inspiration + extension
Clinical: seen in infancy and young children – 6 months to 6 years (older children + adults have peritonsillar + parapharyngeal abscess), 50% cases between 6-12 months, fever / stiff neck / dysphagia / stridor
Cases of Retropharyngeal Abscess
Lateral radiograph of the airway taken in inspiration and extension shows massive thickening of the prevertebral soft tissues.
