Retropharyngeal infections in children

INTRODUCTION — Suppurative infections of the neck are uncommon in children. However, they are potentially very serious. Suppurative cervical lymphadenitis is the most common superficial neck infection. Deep neck infections include peritonsillar abscess, retropharyngeal abscess, and lateral pharyngeal space infection (also known as pharyngomaxillary or parapharyngeal space infection). Lateral pharyngeal space infection most often arises via contiguous spread of infection from a peritonsillar or retropharyngeal abscess.

The clinical features, evaluation, and management of retropharyngeal cellulitis and abscess in children will be discussed here. Cervical lymphadenitis, peritonsillar cellulitis and abscess, and other deep neck space infections are discussed separately. (See "Cervical lymphadenitis in children: Etiology and clinical manifestations" and "Peritonsillar cellulitis and abscess" and "Deep neck space infections in adults".)

ANATOMY AND PATHOGENESIS — The retropharyngeal space extends from the base of the skull to the posterior mediastinum (figure 1). The anterior boundary is the middle layer of the deep cervical fascia (abutting the posterior esophageal wall). The posterior boundary is the deep layer of the deep cervical fascia. These fascia fuse inferiorly at the level between the first and second thoracic vertebrae. The retropharyngeal space communicates with the lateral pharyngeal space. The lateral pharyngeal space is bounded laterally by the carotid sheath, which contains the carotid artery and jugular vein [1]. The "danger" space lies behind the anatomic retropharyngeal space. It is a potential space that provides a path for retropharyngeal infections to extend into the mediastinum.

The retropharyngeal space contains two chains of lymph nodes that are prominent in the young child, but atrophy before puberty [2-4]. These lymph nodes drain the nasopharynx, adenoids, posterior paranasal sinuses, middle ear, and eustachian tube. Infections in these areas may lead to suppurative adenitis of the retropharyngeal lymph nodes [1,2,5,6]. Retropharyngeal abscess is associated with antecedent upper respiratory tract infection in approximately one-half of cases [7].

In approximately one-fourth of cases (usually in older children or adults), retropharyngeal infection is secondary to pharyngeal trauma (eg, penetrating foreign body, endoscopy, intubation attempt, dental procedures) [1,5,7-11]. It also may occur in association with pharyngitis, vertebral body osteomyelitis, and petrositis.

Retropharyngeal infections progress from cellulitis to organized phlegmon (disruption of soft tissue planes without a discreet abscess) to mature abscess [1]. Early institution of appropriate antimicrobial therapy may halt progression to mature abscess [12].

EPIDEMIOLOGY — Retropharyngeal abscess occurs most commonly in children between the ages of two and four years, but can occur in other age groups from neonates [13-15] to adults.

Two to four years is the peak age group for numerous viral upper respiratory tract infections (URI) and their attendant complications, acute otitis media and sinusitis. (See "Acute otitis media in children: Epidemiology, microbiology, and complications", section on 'Bacterial pathogens' and "Acute bacterial rhinosinusitis in children: Clinical features and diagnosis", section on 'Pathogenesis'.)

Examination of a national database covering the years 2000 to 2012 shows an increasing incidence of retropharyngeal abscess [16].

MICROBIOLOGY — Retropharyngeal abscess often is a polymicrobial infection. The predominant bacterial species are Streptococcus pyogenes (group A streptococcus [GAS]), Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA]), and respiratory anaerobes (including Fusobacteria, Prevotella, and Veillonella species) [3,17-22]. Haemophilus species are found occasionally. If appropriate microbiologic techniques are used, then polymicrobial infections caused by aerobes and anaerobes may be identified in a significant minority of patients [3,19].

EVALUATION AND DIAGNOSIS

Address airway obstruction — Rapid assessment of the degree of upper airway obstruction is the initial step in the evaluation of the child with potential deep neck space infection. Anxious, ill-appearing children with drooling and posturing must be monitored continuously in a setting where emergent artificial airway can be established if necessary. (See "Emergency evaluation of acute upper airway obstruction in children", section on 'Emergency airway assessment and management' and "Epiglottitis (supraglottitis): Clinical features and diagnosis", section on 'Acute (fever and stridor)'.)

Patients with severe airway obstruction (eg, anxious, leaning forward with head in the "sniffing position," and marked suprasternal retractions) warrant immediate involvement of airway specialists (eg, anesthesiologist or intensivist and an otolaryngologist) to assist with securing the airway followed by surgical drainage in the operating room. (See "Emergency evaluation of acute upper airway obstruction in children", section on 'No foreign body suspected'.)

Clinical manifestations — The presentation of retropharyngeal abscess depends upon the stage of illness. Early in the disease process, the findings may be indistinguishable from those of uncomplicated pharyngitis. With disease progression, symptoms related to inflammation and obstruction of the upper aerodigestive tract develop.

Children with retropharyngeal abscess generally appear ill with moderate fever. Additional symptoms may include [1,2,6,14]:

●Difficulty swallowing (dysphagia)

●Pain with swallowing (odynophagia)

●Drooling with decreased oral intake

●Neck stiffness; ie, unwillingness to move the neck secondary to pain (torticollis), particularly unwillingness to extend the neck

●Change in vocal quality (muffled, or with a "hot potato" quality [dysphonia]), gurgling sound, or stertor

●Respiratory distress (stridor, tachypnea, or both); stridor develops as disease progresses

●Neck swelling, mass, or lymphadenopathy

●Trismus (in approximately 20 percent of patients)

●Chest pain (in patients with mediastinal extension)

Symptoms of retropharyngeal infection usually progress more slowly than those of epiglottitis, but the two conditions can be difficult to distinguish. Symptoms may be present for several days before diagnosis and the child may have received antibiotics for presumed pharyngitis [6,14,23]. (See 'Differential diagnosis' below.)

Examination of the oropharynx may be limited because of trismus. If drooling is present, suggesting the possibility of epiglottitis, care must be taken not to be too aggressive during examination of the oral cavity. If there is doubt about whether the patient has retropharyngeal infection, epiglottitis, or other deep neck space infection, imaging or, examination in the operating room may be necessary. Examination in the operating room permits controlled placement of an artificial airway if necessary and is recommended if the patient is critically ill or unstable [17]. (See 'Imaging' below and "Epiglottitis (supraglottitis): Clinical features and diagnosis", section on 'Examination'.)

If visualization is adequate, examination of the oropharynx may demonstrate midline or unilateral swelling of the posterior pharyngeal wall. Although digital palpation for fluctuance may be performed by an examiner who is experienced in airway management, it is potentially dangerous (may cause rupture of the abscess into the upper airway) and difficult to accomplish in the emergency department [1]. Thus, we do not recommend it for diagnosis but prefer the use of imaging to confirm the clinical impression. (See 'Imaging' below.)

Tender anterior cervical lymphadenopathy is frequently present. A neck mass may be palpable if the infection has spread to the lateral pharyngeal space.

Laboratory evaluation — The initial laboratory evaluation of a child with suspected retropharyngeal infection should include a complete blood count and blood culture (it is particularly important to send anaerobic as well as aerobic cultures) [1]. Phlebotomy in children who require examination in the operating room should be postponed until after the child is sedated and the airway is secured.

Patients with retropharyngeal abscess usually have increased white blood cell count (WBC) with a predominance of neutrophils and bands [1,2]. In one series of 162 children with retropharyngeal abscess, 91 percent had WBC >12,000/microL; the mean WBC was 22,400/microL [6]. Blood cultures are rarely positive, but may help to identify a pathogen [4].

Specimens for aerobic and anaerobic culture should be obtained at the time of drainage [1]. A standard microbiologic test (throat culture or rapid diagnostic test) for group A streptococci should also be obtained.

Imaging — The radiographic evaluation for retropharyngeal infection may include lateral neck radiographs and/or computed tomography (CT) with contrast of the neck. The imaging strategy depends upon the clinical condition of the patient and level of suspicion for retropharyngeal infection. If there are no signs of airway compromise and the suspicion is low, a lateral neck radiograph may be the initial study; if the suspicion is high, CT with contrast is the preferred study.

CT is usually omitted in children with severe respiratory distress; such children generally undergo evaluation in the operating room, where, if necessary, a surgical airway can be established if tracheal intubation from above is not possible (algorithm 1).

Careful monitoring during transportation and imaging is imperative. For patients undergoing CT, mild airway distress can be exacerbated by sedation and supine positioning; consultation with a pediatric anesthesiologist prior to performing the study is advised if sedation is planned [24].

●Plain radiographs – A lateral neck radiograph may be helpful in supporting the diagnosis of retropharyngeal infection, but is not a definitive study to determine management. Proper technique is critical to appropriate interpretation because false-positive studies are common in children. To avoid a false thickening of the retropharyngeal space, the film should be a perfect lateral obtained during inspiration with the neck held in normal extension [1,25]. False thickening of the retropharyngeal space also may be caused by crying, particularly in infants.

When retropharyngeal infection (cellulitis or abscess) is present, the prevertebral space is increased in depth compared with the anteroposterior measurement of the adjacent vertebral body (image 1). In an infant or child younger than 5 years of age, the retropharyngeal space normally measures one-half the width of the adjacent vertebral body and is considered widened if it is greater than a full vertebral body at C2 or 3 when the spine is properly extended.

Alternatively, the retropharyngeal space is considered pathologically widened if it is greater than 7 mm at C2 or 14 mm at C6 in children and 22 mm at C6 in adults [2,5,26]. Additional features suggestive of retropharyngeal infection include loss or reversal of the normal cervical lordosis due to muscle spasm or local inflammation [2,12]. In some cases, a radiopaque foreign body, soft-tissue mass, air-fluid level, or gas are visualized in the prevertebral area [1,11]. The adjacent spine should be examined for vertebral or intervertebral disease because infections of the spine can spread to the retropharyngeal space.

Anteroposterior and lateral chest radiographs should be obtained in children with suspected retropharyngeal infection to look for extension of infection into the chest (eg, mediastinitis, aspiration pneumonia) [1,12,27]. (See 'Complications' below.)

●Computed tomography – Computed tomography (CT) of the neck with intravenous contrast is the best modality to identify abscesses in the retropharyngeal area.

CT scans can [1,28-30]:

•Generally differentiate between retropharyngeal abscess and cellulitis

•Identify extension of an abscess to contiguous spaces in the neck or chest

•Demonstrate nonradiopaque foreign bodies serving as a nidus for infection

CT can also identify loculations and the position of the carotid artery and internal jugular vein in relation to the infectious process, which is helpful in planning the surgical approach [12,31]. (See 'Surgical drainage' below.)

The abscess may be seen as a mass impinging on the posterior pharyngeal wall. Complete rim enhancement and scalloping of the wall are indicative of an abscess [7,32,33]. Additional CT findings that are common to retropharyngeal abscess and cellulitis include low-density core, soft-tissue swelling, obliterated fat planes, and mass effect (image 2).

Although CT is the test of choice, it is not a perfect test, and clinical judgment must be the ultimate determinant of management. The sensitivity and specificity of CT in predicting purulent material at surgery vary from study to study (ranging from 64 to 100 percent for sensitivity and 45 to 82 percent for specificity) [6,31-37]. These figures must be interpreted with caution because the gold standard test (identification of purulent fluid at surgery) may not always have been performed on the same day as the CT scan and the clinical course may progress between the two. CT and surgical findings might be more closely correlated if surgery was performed soon after the CT was obtained. However, there are well-documented examples of apparent abscesses seen on CT that were not verified at the time of surgery.

DIAGNOSIS — Retropharyngeal infection is suggested by the presence of fever, stiff neck (torticollis or pain with neck extension), dysphagia, and other symptoms related to inflammation or obstruction of the upper aerodigestive tract (eg, drooling, trismus, or chest pain); increased prevertebral space on plain radiographs; and is confirmed by contrast computed tomography (CT) of the neck or by the presence of pus during surgical drainage (algorithm 1).

CT with intravenous contrast is the diagnostic test of choice for stable patients when clinical suspicion is high or when plain radiographs suggest enlargement of the prevertebral space. CT also generally differentiates retropharyngeal abscess from cellulitis. (See 'Imaging' above.)

Patients with suspected retropharyngeal infection and signs of severe airway obstruction should have the airway secured by airway specialists (eg, anesthesiologist or intensivist and an otolaryngologist) followed by surgical drainage in the operating room.

DIFFERENTIAL DIAGNOSIS — The differential diagnosis of retropharyngeal infection includes other conditions that cause upper airway obstruction, sore throat, and/or neck stiffness.

Upper airway obstruction may be caused by [1]:

●Other infections – Epiglottitis, croup, bacterial tracheitis, peritonsillar abscess, uvulitis, laryngopharyngeal diphtheria

●Inflammatory conditions – Multisystem inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2 [38,39] and atypical Kawasaki disease [40]

●Trauma – Penetrating foreign body, foreign body in the airway or esophagus, thermal or caustic burns of the posterior pharynx

●Angioedema or anaphylaxis

●Tumors – Lymphangioma (cystic hygroma), hemangioma

Clinical features and imaging studies usually distinguish between these possibilities. As examples, epiglottitis is usually more rapidly progressive than retropharyngeal infection and has the characteristic "thumb sign" on lateral soft tissue radiograph of the neck (image 3). Atypical Kawasaki disease and MIS-C are characterized by older age (> 4 years) and non-response to antibiotics in contrast to children with retropharyngeal abscess [38-40]. The evaluation of acute upper airway obstruction is discussed separately. (See "Emergency evaluation of acute upper airway obstruction in children".)

The causes of sore throat in children of various ages are listed in the table (table 1). The evaluation of children with sore throat is discussed separately. (See "Evaluation of sore throat in children".)

Causes of neck stiffness and/or torticollis that must be considered in children with possible retropharyngeal abscess include [1,7,41]:

●Meningitis (see "Bacterial meningitis in children older than one month: Clinical features and diagnosis", section on 'Clinical features' and "Viral meningitis in children: Clinical features and diagnosis", section on 'Clinical features')

●Cervical spine arthritis or osteomyelitis; retropharyngeal abscess also may occur as a complication of cervical vertebral osteomyelitis (see "Hematogenous osteomyelitis in children: Clinical features and complications", section on 'Vertebral bodies and intervertebral discs')

●Tuberculous abscess of the cervical spine (see "Bone and joint tuberculosis")

●Spinal injury (see "Evaluation and acute management of cervical spine injuries in children and adolescents")

●Dystonic reaction

●Various toxins (tetanus, black widow spider bite, scorpion sting)

As with upper airway obstruction, clinical features (eg, history of trauma or exposure to tuberculosis, drugs, or toxins) may distinguish these conditions from retropharyngeal abscess. The evaluation of torticollis in children is discussed separately. (See "Acquired torticollis in children".)

MANAGEMENT

Initial therapy — Randomized controlled trials evaluating management of retropharyngeal infections are lacking. Recommendations for treatment are based upon the causative pathogens and response to therapy described in observational studies [4,14,34,42-47].

Initial therapy depends upon the severity of respiratory distress and likelihood of drainable fluid (based upon computed tomography [CT] findings and clinical features, such as duration of symptoms and clinical course) (algorithm 1):

●In patients with severe airway compromise (eg, anxious, leaning forward with head in the "sniffing position," stridor, and marked suprasternal retractions), secure the airway immediately and proceed to emergency surgical drainage. (See 'Surgical drainage' below.)

●We also suggest surgical drainage for stable patients with CT imaging showing abscesses that are large (≥2.5 cm²) and consistent with a mature abscess (complete rim enhancement and scalloping). (See 'Surgical drainage' below.)

●We suggest that children with retropharyngeal abscesses and no airway compromise receive a trial of antibiotic therapy for 24 to 48 hours without surgical drainage, especially if the CT findings are not consistent with a mature abscess that is ≥2.5 cm² [4,32,43]. (See 'Antimicrobial therapy' below.)

●Initiate empiric intravenous antibiotic therapy as soon as possible after surgical drainage or once the decision is made to treat without surgical drainage. (See 'Empiric therapy' below.)

Children with suspected retropharyngeal infection should be hospitalized and managed in consultation with an otolaryngologist [48]. Particular attention must be paid to maintenance of the airway. Intubation or, less commonly, tracheotomy may be necessary in patients with respiratory compromise [1,48].

Response to antimicrobial therapy is indicated by improvement in symptoms. CT with contrast should be performed if there is no clinical improvement 24 to 48 hours after initiation of antibiotic therapy.

The optimal management of retropharyngeal abscess in patients without imminent airway obstruction is unclear [6]. We favor a trial of antimicrobial therapy for 24 to 48 hours, especially in patients with small abscesses (eg, cross-sectional area <2.5 cm²) [4,14,32,42-47]. Some experts advocate immediate drainage in conjunction with antimicrobial therapy for all presumed abscesses [33].

Factors that have been associated with drainable fluid at surgery include duration of symptoms for more than two days and cross-sectional area >2 cm² on CT scan [6]. Although it was thought that early surgical drainage in such patients would shorten the length of stay in the hospital and reduce cost of treatment [6], limited evidence does not support this hypothesis. For example, in an analysis of retropharyngeal and parapharyngeal abscess in children reported to a national inpatient pediatric hospital database, surgical drainage was associated with a longer length of stay and higher costs compared with patients who did not receive surgery [16]. Most surgeries were performed on the day of or the day after admission. Interpretation of these results is limited by lack of detail regarding abscess size and severity of illness for individual patients.

Children with retropharyngeal infections must be monitored closely for persistence or progression of symptoms and complications. (See 'Complications' below.)

Supportive care — Supportive care for the child with retropharyngeal infection includes maintenance of the airway, adequate hydration, provision of analgesia, and monitoring for complications. Patients with an unstable airway should be monitored in the intensive care unit; endotracheal intubation may be necessary for airway maintenance.

Antimicrobial therapy — Antimicrobial therapy is a necessary component of the treatment of retropharyngeal infections in children (algorithm 1). In the pre-antibiotic era, the mortality rates for deep neck space infections in children ranged from 7 to 15 percent and complications occurred in as many as 25 percent [4]. With the advent of antibiotic therapy, mortality and complications are uncommon.

Successful treatment of suppurative retropharyngeal infection with antimicrobial therapy alone has been reported in observational studies [4,14,32,42,43,47]. Success rates in retrospective series range from 37 to 75 percent [14,32,43]. In a small prospective series, 10 of 11 children with suppurative deep neck infections greater than 1 cm² responded to antibiotic therapy without developing complications [4].

Potential risks of nonsurgical management include spontaneous rupture, respiratory distress requiring intubation or temporary tracheostomy, and longer hospital stay [6,46,49].

Empiric therapy — Empiric therapy should include coverage for group A Streptococcus, S. aureus, and respiratory anaerobes. Empiric therapy can be amended as necessary based upon culture results if drainage is performed or clinical response to treatment. When tailoring therapy based upon culture results, it is important to bear in mind that retropharyngeal infections are frequently polymicrobial, and not all microbes are consistently cultured [24]. (See 'Microbiology' above.)

Empiric regimens include [1]:

●Ampicillin-sulbactam (50 mg/kg per dose every six hours intravenously), or

●Clindamycin (15 mg/kg per dose [maximum single dose 900 mg] every eight hours intravenously)

However, ampicillin-sulbactam does not provide antibacterial activity against methicillin-resistant S. aureus (MRSA) and, depending upon local susceptibility patterns, clindamycin may not be active against group A Streptococcus [50], methicillin-susceptible S. aureus, and/or MRSA.

Accordingly, in patients who do not respond to initial treatment with the empiric regimens above or who present with moderate or severe disease, intravenous vancomycin or linezolid should be added to empiric treatment with either ampicillin-sulbactam or clindamycin to provide optimal coverage for potentially-resistant Gram-positive cocci as follows:

●Vancomycin (40 to 60 mg/kg per day divided in three to four doses; maximum daily dose 2 to 4 g)

OR

●Linezolid (<12 years: 30 mg/kg per day divided in three doses; ≥12 years: 20 mg/kg per day in two doses; maximum daily dose 1200 mg) (see "Methicillin-resistant Staphylococcus aureus infections in children: Epidemiology and clinical spectrum", section on 'CA-MRSA strains')

Parenteral treatment is maintained until the patient is afebrile and clinically improved. Oral therapy should be continued to complete a 14-day course. Appropriate oral regimens for continuation of therapy include:

●Amoxicillin-clavulanate (45 mg/kg per dose every 12 hours)

OR

●Clindamycin (13 mg/kg per dose every 8 hours) if the patient responded to the empiric use of parenteral clindamycin

When vancomycin has been added to the parenteral regimen, linezolid may be used for oral therapy.

Response to therapy — Response to antimicrobial therapy is indicated by improvement in symptoms and defervescence [1,46,47]. CT with contrast should be performed if there is no clinical improvement 24 to 48 hours after initiation of antibiotic therapy (algorithm 1) [1,42].

Treatment failure is defined by lack of symptomatic improvement or worsening despite 24 to 48 hours of antimicrobial therapy (with or without surgical drainage). Treatment failure may occur in patients who have developed complications, are infected with unusual organisms, or have underlying problems (eg, congenital cyst or tract) [24]. Reevaluation of such patients may include repeat imaging (CT with contrast to look for extension of infection) or surgical intervention. Broadening antimicrobial therapy to cover MRSA and Gram-negative rods may also be indicated.

Corticosteroid therapy — We do not administer systemic corticosteroids to children with retropharyngeal infections. Several retrospective observational studies have reported that administration of systemic corticosteroid along with empiric antibiotics to children with retropharyngeal infections may be associated with a decreased rate of surgical drainage [51-53]. However, all of the studies are retrospective and uncontrolled with a significant risk of confounding. In addition, in the largest of these studies, use of systemic corticosteroids was also associated with delayed surgery which suggests that clinical features may have been masked [51].

Surgical drainage — Surgical drainage in conjunction with antibiotic therapy has played a prominent role in the management of retropharyngeal abscess.

Indications for surgical drainage may include (algorithm 1) [6,14,44]:

●Airway compromise or other life-threatening complications

●A large (≥2.5 cm²) hypodense area on CT scan that is consistent with a mature abscess (complete rim enhancement and scalloping)

●Failure to respond to parenteral antibiotic therapy (persistence of fever, pain, and development of a large [≥2.5 cm²] abscess)

If surgical drainage is performed, specimens for aerobic and anaerobic culture should be obtained [1].

Surgical drainage is usually performed transorally unless the abscess is lateral to the neck vessels or involves multiple deep neck space infections [1,6,35]. A second procedure may be required in a minority of cases [6,23]. Complications related to surgical drainage are rare.

Discharge instructions — Patients who are discharged from the hospital after treatment for retropharyngeal infection should be instructed that prompt reevaluation is necessary for the following symptoms [24]:

●Dyspnea

●Worsening throat pain, neck pain, or trismus

●Enlarging mass

●Fever

●Neck stiffness

Follow-up should be arranged within several days of discharge.

COMPLICATIONS — Complications of retropharyngeal abscess occur rarely but are potentially fatal. Infection can spread from the retropharyngeal space to other deep neck spaces, to adjacent structures, and to the bloodstream.

Complications include [1,17,54]:

●Airway obstruction

●Septicemia

●Aspiration pneumonia if the abscess ruptures into the airway

●Internal jugular vein thrombosis

●Jugular vein suppurative thrombophlebitis (Lemierre syndrome) [55]

●Carotid artery rupture [56]

●Mediastinitis (suggested by widening of the mediastinum on chest radiograph) [27]

●Atlantoaxial dislocation [15,57,58]

PROGNOSIS — When detected early and appropriately treated, retropharyngeal abscess seldom leads to long-term consequences [6]. The duration of hospitalization, which is dependent on the response to management, is usually three to five days unless the child requires mechanical ventilation following surgery [4,23]. Relapse occurs in 1 to 5 percent of cases, and may be associated with trauma or anatomic abnormality [7,12,15,57,58].

SUMMARY AND RECOMMENDATIONS

●Clinical features and diagnosis

•Stabilization – Rapid assessment of the degree of upper airway obstruction is the initial step in the evaluation of the child with potential deep neck space infection. Patients with signs of retropharyngeal abscess and severe airway obstruction (eg, anxious, leaning forward with head in the "sniffing position," and marked suprasternal retractions) warrant immediate involvement of airway specialists (eg, anesthesiologist or intensivist and an otolaryngologist) to assist with securing the airway. (See 'Address airway obstruction' above.)

•Clinical manifestations – Retropharyngeal infection should be considered in children who present with fever, stiff neck, pain with neck extension, dysphagia, and other symptoms related to inflammation or obstruction of the upper aerodigestive tract. Neck stiffness is an important symptom and may occur in the absence of respiratory symptoms. (See 'Evaluation and diagnosis' above.)

Examination of the oropharynx may be limited if the child is unable to open his or her mouth widely and should be avoided in children with significant airway compromise. If visualization is adequate, it may be possible to appreciate midline or unilateral swelling of the posterior pharyngeal wall. (See 'Clinical manifestations' above.)

•Imaging – In stable patients without significant airway compromise, computed tomography (CT) of the neck with intravenous contrast is the preferred study to confirm the diagnosis of retropharyngeal infection and to differentiate retropharyngeal abscess from cellulitis. (See 'Diagnosis' above and 'Imaging' above.)

●Management

•Initial therapy – Children with suspected retropharyngeal infection should be hospitalized and managed in consultation with an otolaryngologist. Particular attention must be paid to maintenance of the airway. Initial therapy depends upon the severity of respiratory distress and likelihood of drainable fluid (based upon CT findings and clinical features, such as duration of symptoms and clinical course) (algorithm 1) (see 'Initial therapy' above):

-Surgical drainage – In patients with severe airway compromise (eg, anxious, leaning forward with head in the "sniffing position," stridor, and marked suprasternal retractions), secure the airway immediately and proceed to emergency surgical drainage. (See 'Surgical drainage' above.)

We also suggest surgical drainage for stable patients with CT imaging showing abscesses that are large (≥2.5 cm²) and consistent with a mature abscess (complete rim enhancement and scalloping) (Grade 2C). (See 'Surgical drainage' above.)

-Antimicrobial therapy – We suggest that children with retropharyngeal abscesses and no airway compromise receive a trial of empiric intravenous antibiotic therapy for 24 to 48 hours without surgical drainage, especially if the CT findings are not consistent with a mature abscess that is ≥2.5 cm² (Grade 2C). Initiate empiric intravenous antibiotic therapy as soon as possible after surgical drainage or once the decision is made to treat without surgical drainage. Empiric antibiotic therapy should include coverage for group A Streptococcus (GAS), Staphylococcus aureus (including methicillin-resistant S. aureus [MRSA], if appropriate), and respiratory anaerobes. (See 'Antimicrobial therapy' above.)

Response to antimicrobial therapy is indicated by improvement in symptoms. CT with contrast should be performed if there is no clinical improvement 24 to 48 hours after initiation of antibiotic therapy. (See 'Response to therapy' above.)