Diagnosing deep space neck infections is important since they can cause respiratory compromise. A differential including peritonsilar abscess, retropharyngeal abscess, Ludwigs angina, epiglottitis, meningitis, and Lemierre syndrome should be considered in the patient who presents with trismus, muffled voice and limited neck mobility.
Retropharyngeal abscesses (RPA) occur in the potential space bound anterior to the prevertebral fascia, posterior to the pharyngeal constrictor muscles and their fascia and laterally by the carotid sheaths and parapharyngeal space (another potential space lying laterally to the pharynx). The retropharyngeal potential space runs superiorally from the base of the skull to the mediastinum distally. It is the most common deep neck infection. In children under 4 years of age, retropharyngeal lymph nodes are present which regress after this age.
Look for neck stiffness or limited range of motion of the neck. Limited ROM of the neck may present as dramatically as torticollis or more subtly as the patient refusing to look in a direction.
The peak incidence occurs in 3- to 5-year-olds. It is rare beyond 6 years of age as the retropharyngeal lymph nodes involute.
Lateral neck soft tissue XRAY: Evaluation of prevertebral soft tissue.
Should be obtained in extension on inspiration: Flexion of the neck, expiration and crying may result in pseudo-enlargement.
How do you diagnose retropharyngeal abscess? Lateral neck X-ray or CT scan.Anteroposterior (AP) diameter of soft tissues along anterior bodies of C1- 4 should be less than 40% of the AP diameter of the vertebral body behind it.
Ted Brenkert sticks his neck out to educate you on retropharyngeal abscesses. RPAs can be an especially worrisome diagnosis in young children who will present with fever, sore throat and limitation of neck movement.
Pearl: these patients prefer to lie flat (vs. epiglottitis patients prefer to sit up/tripoding)
Retropharyngeal abscesses are uncommon but potentially life-threatening diagnosis. They can occur at any age, although are most commonly found in children under the age of five.
Patients may prefer to lay supine to prevent abscess and edematous posterior wall to collapse into airway, so patients should not be forced to sit up