Retropharyngeal abscess is a purulent collection in the retropharyngeal space (between the buccopharyngeal fascia and alar fascia). In children (<5 years), suppuration of retropharyngeal lymph nodes (Rouviere nodes — nodes draining nasopharynx, paranasal sinuses, and middle ear infections) is the most common cause; since these nodes atrophy by age 5-6, different mechanisms predominate in adults (penetrating trauma, foreign body ingestion, dental infection spread, vertebral osteomyelitis). CT shows retropharyngeal hypodense collection + rim enhancement + prevertebral edema. Spread to the mediastinum via the danger space (between alar fascia and prevertebral fascia) poses a life-threatening risk — posterior mediastinum can extend to T4 vertebra, anterior mediastinum to the diaphragm.
Age Range
0-65
Peak Age
4
Gender
Male predominant
Prevalence
Uncommon
Retropharyngeal abscess formation shows different pathogenesis by age. In children: Upper respiratory tract infection (nasopharyngitis, otitis media, sinusitis) → lymphatic spread to retropharyngeal lymph nodes (Rouviere) → suppurative lymphadenitis → nodal necrosis and abscess formation. Rouviere nodes are located at C1-C3 vertebral level and atrophy by age 5-6 — hence much more common in children. In adults: Penetrating trauma (fish bone, endoscopy), foreign body, dental/peritonsillar abscess spread, vertebral osteomyelitis/discitis (posterior route), or IV drug use. In abscess formation, bacteria (Streptococcus, Staphylococcus, anaerobes) cause tissue necrosis and pus formation. On CT: The necrotic center is avascular, showing low density and no enhancement; surrounding granulation tissue contains neovascularization creating rim enhancement. Prevertebral soft tissue edema (>7mm at C2, >14mm at C6 level is pathological) shows the extent of the inflammatory process. Critical anatomical relationship: the retropharyngeal space communicates with the posterior mediastinum (to T4) and anterior mediastinum (to diaphragm) via the 'danger space' — spread of infection to these potential spaces dramatically increases mediastinitis and mortality risk.
Rim-enhancing hypodense collection in the retropharyngeal space on contrast CT. Contains well-defined fluid collection unlike cellulitis. Gold standard finding for abscess diagnosis.
On contrast-enhanced CT, a hypodense fluid collection + rim (ring) enhancement in the retropharyngeal space (anterior to prevertebral muscles, posterior to pharyngeal constrictors). Collection is usually midline or slightly off-midline. Internal density 0-25 HU (purulent fluid). Wall thickness may be irregular. Gas bubbles suggest anaerobic infection. Cellulitis distinction is important: no collection in cellulitis, only diffuse edema and stranding.
Report Sentence
A __ x __ mm rim-enhancing hypodense collection is seen in the retropharyngeal space. Internal density is approximately __ HU, consistent with purulent collection. Gas bubbles [are present/are not identified]. Findings are consistent with retropharyngeal abscess.
Prevertebral soft tissue is thickened with edema showing fat stranding. Normal prevertebral soft tissue thickness: <7mm at C2 level, <14mm at C6 level (thinner in children). Exceeding these values is considered pathological. Edema and stranding indicate spread of the inflammatory process to the prevertebral space. Vertebral body and disc osteomyelitis/discitis findings should be sought (in adult cases).
Report Sentence
Prevertebral soft tissue measures __ mm at C2 level, __ mm at C6 level (exceeds pathological limits). Fat stranding and edema are seen.
Retropharyngeal abscess may extend to the mediastinum via the danger space — in this case, posterior mediastinal collection, mediastinal widening, and fat stranding are seen on chest CT. Mediastinal extension increases mortality up to 50%. Chest CT should be routinely performed in retropharyngeal abscess cases. Pneumomediastinum may accompany as an additional finding.
Report Sentence
The retropharyngeal collection shows mediastinal extension via the danger space. Posterior mediastinal collection is seen. Mediastinal fat stranding is present. EMERGENT surgical evaluation is recommended.
The retropharyngeal collection shows marked diffusion restriction on DWI — high DWI signal and low ADC values. Diffusion restriction reflects the high viscosity and cellular content of purulent material. This finding is very helpful in distinguishing abscess from reactive effusion/edema.
Report Sentence
Marked diffusion restriction is seen in the retropharyngeal collection on DWI (high DWI signal, low ADC). This finding is consistent with purulent content and abscess formation.
The retropharyngeal collection displaces the airway anteriorly (mass effect). Oropharyngeal or hypopharyngeal lumen may be narrowed. In severe cases, airway compromise may develop. Measurement of airway diameter is critical for emergent airway management decisions.
Report Sentence
The retropharyngeal collection displaces the airway anteriorly. The [oropharyngeal/hypopharyngeal] lumen is narrowed with residual diameter of approximately __ mm. Airway compromise [is present/is at risk/is not identified].
Criteria
<5 years, upper respiratory infection history, at C1-C3 level
Distinct Features
Transoral drainage usually sufficient. Better prognosis. Suppurative lymph node may be visible.
Criteria
History of penetrating trauma, foreign body, dental infection, or vertebral osteomyelitis
Distinct Features
Etiology should be investigated (foreign body, vertebral infection). Higher risk of mediastinal extension. Surgical drainage usually necessary.
Criteria
Spread to mediastinum via danger space, posterior mediastinal collection on chest CT
Distinct Features
Mortality can reach up to 50%. Requires emergent thoracic surgery. Mediastinitis treatment involves aggressive debridement + prolonged antibiotics.
Distinguishing Feature
Epiglottitis involves supraglottic structures; in retropharyngeal abscess epiglottis is normal, collection is in retropharyngeal space.
Distinguishing Feature
Cartilage fracture + emphysema in trauma; rim-enhancing collection + fever in abscess.
Distinguishing Feature
Stenosis is chronic, subglottic, concentric narrowing; abscess is acute, collection in retropharyngeal space.
Urgency
emergentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralRetropharyngeal abscess is an airway and mediastinitis emergency. IV broad-spectrum antibiotics are started immediately. Surgical drainage is required for abscess diagnosis (transoral or external approach). If mediastinal extension is present, emergent thoracic surgery is performed. In children, transoral drainage is usually sufficient; in adults, external approach may be preferred. Etiology should be investigated (foreign body, vertebral infection).
Retropharyngeal abscess is an airway emergency. IV antibiotics + surgical drainage form the basis of treatment. Mediastinal extension (via danger space) dramatically increases mortality — requires emergent thoracic surgery. In children, transoral drainage is usually sufficient.