Emergent Care / Stabilization: Emergency care may include intravenous (IV) broad-spectrum antibiotics, surgical drainage, and airway support.
Diagnosis Overview: A retropharyngeal abscess (RPA) is a rare, yet dangerous, deep neck space infection characterized by a collection of pus located in the retropharyngeal space (the space behind the hypopharynx and esophagus).
This infection, as with other deep neck space infections, is usually odontogenic (most commonly) or originates in the upper respiratory tract and spreads along nearby tissue planes. This infection can also spread contiguously from a focus of vertebral osteomyelitis or epidural abscess. Penetrating trauma of the pharynx (eg, from an animal bone) or instrumentation is another risk factor for this infection. Infections of the retropharyngeal space can extend to involve the lateral pharyngeal space and the carotid sheath. Infections can additionally reach the mediastinum via spread in the retropharyngeal space or via the "danger space," which lies between the alar and prevertebral fascia. The most dangerous complication of spread is acute necrotizing mediastinitis, which is difficult to treat and has a high mortality.
Organisms usually involved in this infection are mouth and upper respiratory tract flora, most notably: group A Streptococcus, Staphylococcus aureus, Streptococcus pneumoniae, Viridans-group Streptococci, Haemophilus influenzae, and oral anaerobes (Fusobacterium species, Prevotella species, Bacteroides species, Peptostreptococcus species). Infection is frequently polymicrobial.
Adult RPA may present with odynophagia, neck pain, torticollis, trismus, fever, and dyspnea. Neck pain may be unilateral, and examination may reveal a bulging of the posterior wall of the oropharynx. Airway compromise and toxic appearance are signs of a very severe infection, and subcutaneous emphysema indicates acute mediastinitis, both requiring immediate intervention.
A CT scan of the neck with contrast can identify an RPA and is the imaging method of choice. A lateral x-ray of the neck can be used as a rapid screening method if airway compromise is present. Treatment involves surgical drainage in addition to IV antibiotic therapy. Airway support in the form of intubation may be necessary, depending on the status of the patient.
ICD10CM: J39.0 – Retropharyngeal and parapharyngeal abscess
SNOMEDCT: 18099001 – Retropharyngeal abscess
Differential Diagnosis & Pitfalls
Cervical osteomyelitis – More likely if there is not an obvious peritonsillar abscess seen on imaging.
Retropharyngeal cellulitis – CT scan will be able to differentiate (no evidence of fluid). May be a precursor to the development of an abscess.