Retropharyngeal Abscess

Updated: Jan 08, 2021
  • Author: Joseph H Kahn, MD; Chief Editor: Gil Z Shlamovitz, MD, FACEP  more...
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Overview

Practice Essentials

Retropharyngeal abscess (RPA) produces the symptoms of sore throat, fever, neck stiffness, and stridor. RPA occurs less commonly today than in the past because of the widespread use of antibiotics for suppurative upper respiratory infections. The incidence of RPA in the United States is rising, however. Once almost exclusively a disease of children, RPA is observed with increasing frequency in adults. It poses a diagnostic challenge for the emergency physician because of its infrequent occurrence and variable presentation. [1]  Emergency department (ED) management of retropharyngeal abscess includes attention to the airway, fluid resuscitation if necessary, antibiotic treatment, and preparation for an emergency operation, if indicated.

Early recognition and aggressive management of RPA are essential because it still carries significant morbidity and mortality.

Signs of retropharyngeal abscess

Physical signs of RPA in adults include the following:

  • Posterior pharyngeal edema
  • Nuchal rigidity
  • Cervical adenopathy
  • Fever
  • Drooling
  • Stridor
  • Torticollis [2]
  • Trismus [2]

Physical signs of RPA in infants and children include the following:

  • Cervical adenopathy [3]
  • Retropharyngeal bulge - Do not palpate in children [3]
  • Fever [3]
  • Stridor
  • Torticollis
  • Neck stiffness [3]
  • Drooling
  • Agitation
  • Neck mass [3]
  • Lethargy
  • Respiratory distress
  • Trismus [4]
  • Change in vocal quality [4]
  • Tonsillar displacement
  • Associated signs, including tonsillitis, peritonsillitis, pharyngitis, and otitis media

Workup in retropharyngeal abscess

Laboratory studies include the following:

  • Complete blood count (CBC)
  • Blood cultures - Indicated before administration of intravenous antibiotics, but culture results may be negative in as many as 82% of RPA cases
  • A culture of pus - Aspirated at the time of surgical drainage of the RPA, it can grow one or more organisms 91% of the time
  • C-reactive protein
  • Erythrocyte sedimentation rate [5]
  • COVID-19 testing - In adult or pediatric patients who present with a sore throat [6]

Imaging studies include the following:

  • Lateral neck radiography
  • Computed tomography (CT) scanning of the neck - Obtain a CT scan of the neck with intravenous contrast when the findings on the lateral neck radiograph are equivocal or if the clinical suspicion for RPA is high in patients with negative findings on lateral neck radiograph
  • Chest radiography - A chest radiograph is indicated to look for aspiration pneumonia and mediastinitis
  • Magnetic resonance imaging (MRI) with gadolinium enhancement - This modality can reveal the existence and size of a retropharyngeal abscess, although the imaging study takes long than does CT scanning [7]

Management of retropharyngeal abscess

ED management of RPA includes attention to the airway, fluid resuscitation if necessary, antibiotic treatment, and preparation for an emergency operation, if indicated. Frequent vital sign checks and continuous oxygen saturation monitoring are essential.

Securing the airway may be required if the patient with RPA is exhibiting signs of impending upper airway obstruction. Endotracheal intubation may be attempted, but it may be difficult because of distortion of the upper airway. The preferred approach is intubation in the operating room (OR), with the surgeon and anesthesiologist present. [8]

If a patient with signs of upper airway obstruction cannot be intubated, a surgical or needle cricothyrotomy may be required, but distortion due to edema and inflammation may make surgical airway management difficult. [9]

A tracheostomy may be required as definitive airway management in patients with retropharyngeal abscess and respiratory distress, but this may also be technically challenging due to edema and inflammation. [9]

Intravenous fluids are required if the patient is dehydrated because of fever and difficulty swallowing.

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Pathophysiology

The retropharyngeal space is posterior to the pharynx, bound by the buccopharyngeal fascia anteriorly, the prevertebral fascia posteriorly, and the carotid sheaths laterally. It extends superiorly to the base of the skull and inferiorly to the mediastinum.

Abscesses in this space are often polymicrobial; they can be caused by the following organisms:

  • Aerobic organisms, such as group A streptococci and Staphylococcus aureus, including methicillin-resistant S aureus (MRSA) [10]

  • Anaerobic organisms, such as species of BacteroidesVeillonella, Prevotella, Peptostreptococcus, Fusobacterium, and Porphyromonas [10]

  • Gram-negative organisms, such as Pseudomonas (in high-risk groups), Haemophilus influenzae, H parainfluenzae, and others [11, 12]

The high mortality rate of retropharyngeal abscess is owing to its association with airway obstruction, mediastinitis, aspiration pneumonia, epidural abscess, jugular venous thrombosis, necrotizing fasciitis, sepsis, and erosion into the carotid artery.

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Epidemiology

Frequency

United States

The incidence of pediatric RPA in the United States more than doubled in the first decade of the 21st century, according to a study of pediatric deep neck space infections. Deriving their statistics from the Kids’ Inpatient Database (KID), Novis et al found that between 2000 and 2009, the incidence of RPA increased from 0.1 cases per 10,000 to 0.22 cases per 10,000. They also found no significant change in the incidence of either peritonsillar or parapharyngeal abscess in those years. [13]

A study by Woods et al, also using the KID, reported the incidence of RPA to have risen, among children under age 20 years, from 2.98 per 100,000 population in 2003 to 4.10 per 100,000 population in 2012. [14]

A review of cases of RPA over an 11-year period at the Children's Hospital of Michigan revealed a 4.5-times increase in the incidence of RPA when compared with the previous 12 years. [15] A later review at the same hospital revealed that the incidence increased 2.8-fold between 2004 and 2010, compared with the incidence from 1993-2003. [16]

Similarly, an 11-year chart review of 162 pediatric patients with RPA at St. Louis Children's Hospital revealed that the number of RPA cases in children increased significantly from 1995 to 2006. [17]

A study by Angajala et al determined that of 119 pediatric patients in the greater Los Angeles community with a neck abscess treated with incision and drainage, 10.1% had an RPA. Patients with neck abscesses requiring incision and drainage tended to reside in lower income neighborhoods. [18]

International

A review of deep neck infections (DNI) in children over a 12-year period at a medical center in Taiwan revealed 50 children with DNI. Nine children had DNI in the retropharyngeal space, 17 in the parapharyngeal space, 21 in the peritonsillar region, and 3 were mixed. [19]

Another study from Taiwan, by Huang et al, found that out of 52 children with DNI, the retropharyngeal space was the third most common site of infection (7 patients), after the parapharyngeal space (22 patients) and the submandibular space (12 patients). [20]

A review of RPAs and parapharyngeal abscesses (PPAs) in children presenting to 2 pediatric tertiary care medical centers in Israel over an 11-year period revealed 39 children with RPA or PPA. The incidence increased during the course of the study. [21]

A retrospective analysis of children diagnosed with RPA and PPA over a 9-year period in a tertiary care medical center in Spain revealed 17 children with RPA, 11 with PPA, and 3 with both. [22]

Another Spanish study, a retrospective, single-center report by Sanz Sánchez and Morales Angulo, found the incidence of RPA over an approximately 25-year period to be 0.2 cases per 100,000 inhabitants per year. [23]

A study by Yap et al found that in Wales, hospital admissions for RPA, as well as for tonsillitis, PPA, and peritonsillar abscess, rose between 1999 and 2014. [24]

A retrospective review at a single center in Scotland revealed that the number of deep neck space abscesses grew between 2006 and 2015 from 1 to 15, respectively. [25]

Mortality/Morbidity

Once mediastinitis occurs, mortality approaches 25%, even with antibiotic therapy. Retropharyngeal abscess can also cause internal jugular vein thrombosis, carotid artery erosion, pericarditis, and epidural abscess. In addition to invasion of contiguous structures, retropharyngeal abscess can cause sepsis and airway compromise. [7]

Overall mortality rate was 1% in a review of deep cervical space infections in Taiwan. [26]

In a study of 234 adults with deep space infections of the neck in Germany, the mortality rate was 2.6%. The cause of death was primarily sepsis with multiorgan failure. [27]

In the United States, in 2003, a review of the Kids' Inpatient Database (KID) revealed 1321 pediatric admissions with RPA, with no fatalities. [28]

A case series from Children's National Medical Center in Washington DC presents 4 children of ages ranging from 8 months to 18 months with RPA who developed mediastinitis. All 4 were treated aggressively with antibiotics and surgical drainage of RPA, and 3 patients required thoracoscopic debridement. All 4 children survived without sequelae. [29]

Race

In a 10-year review of retropharyngeal abscess cases treated at Kings County Hospital in Brooklyn, New York, 70% of patients were Black, 25% were White, and 5% were Hispanic.

A study of pediatric patients with retropharyngeal abscess at Wayne State University in Detroit revealed 43% of cases occurred in Blacks, 54% in Whites, 1% in Hispanics, and 1% in biracial. [30]

In the United States, in 2003, a review of the Kids' Inpatient Database (KID) revealed 1321 pediatric admissions with retropharyngeal abscess, of which 37.4% were White, 11.7% were Black, 11.1% were Hispanic, 2% were Asian, and 3.8% were other races, with the race not being recorded in the rest of the patients. [28]

Sex

Retropharyngeal abscess is more common in males than in females, with generally reported male preponderance of 53-55%.

  • Children's Hospital of Michigan reports 54% of cases of RPA in males in a 2012 study. [16]

  • A study of children with retropharyngeal abscess in Toronto reported 67% of cases in males.

  • A study of retropharyngeal abscess in children in Detroit found 56% of cases in males. [30]

  • A study of adults with deep space infections of the neck in Germany revealed that 56% of patients were male and 44% were female. [27]

  • A study of cases in Nigeria found a male-to-female ratio of 1:1. [31]

  • In the United States, in 2003, a review of the Kids' Inpatient Database (KID) revealed 1321 pediatric admissions with retropharyngeal abscess, of which 63% were male. [28]

Age

Initially, retropharyngeal abscess was thought to be a disease limited to children, but now it is being encountered with increasing frequency in adults.

  • In children, retropharyngeal abscesses develop most frequently between the ages of 2 and 4 years. [4]

  • This was supported by a review by Bochner, which found the incidence to be greatest in children younger than age 5 years and, by gender, in boys. [5]

  • A review of adults with deep space infections of the neck in Germany revealed a mean age (±standard deviation) of 44.5 (±21.8) years.

  • A review of retropharyngeal abscess cases at the Hospital for Sick Children in Toronto revealed that 66% of pediatric cases occurred in children younger than 6 years.

  • A review of 30 cases of retropharyngeal abscess over an 11-year period in Nigeria found the median age to be 21 months, and 77% of patients were younger than 5 years. Eighty-three percent of retropharyngeal abscesses occurred in children, and 17% occurred in adults. [31]

  • A 10-year review at Kings County Hospital in Brooklyn, New York, revealed that 30% of the cases were in pediatric patients aged 16 months to 8 years and 70% were in adults aged 21-64 years.

  • A 35-year review of cases involving children who were treated for retropharyngeal abscess at the Children's Hospital of Los Angeles revealed that 50% of patients were younger than 3 years and 71% were younger than 6 years.

  • A review or retropharyngeal abscess in children in Detroit found a mean age of 4.1 years, with a range from 2 months to 18 years.

  • A review in Sydney, Australia, found that, in 55% of pediatric cases of retropharyngeal abscess, the children were younger than 1 year, with 10% diagnosed in the neonatal period.

  • A review of RPA cases in children in Albuquerque revealed a median age of 36 months, with 75% of patients younger than 5 years and 16% of patients younger than 1 year. [32]

  • In the United States, in 2003, a review of the Kids' Inpatient Database (KID) revealed 1321 pediatric admissions with retropharyngeal abscess, with an average age of 5.1 years (SD, 4.4). [28]

  • An 11-year chart review of 162 pediatric patients with retropharyngeal abscess at St. Louis Children's Hospital revealed an average age of 4.9 years (range, 6 d to 17 y). [17]

  • A 5-year review of 11 children with parapharyngeal abscess in Portugal revealed an average age of 3.3 years (range, 0-12 y). [3]

  • A 12-year retrospective review of 50 pediatric patients with deep neck infections in Taipei revealed that all of the retropharyngeal abscesses occurred in children younger than 10 years. [19]

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