Infectious Disorders – Drug Targets, 2012, 12, 291-296 291 Retropharyngeal Abscess: Diagnosis and Treatment Update 1 2,3 Brian K. Reilly * and James S. Reilly 1Children’s National Medical Center, Washington, DC; USA; 2Chair, Department of Surgery, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA; 3Professor of Otolaryngology and Pediatrics, Thomas Jefferson Univer- sity, Philadelphia, PA, USA Abstract: Retropharyngeal abscess is a deep neck space infection that may present in various subtle ways permitting po- tentially lethal complications to occur before appropriate diagnosis is made and expedient management undertaken. This article reviews in detail the pertinent anatomy, diagnostic pearls, and clinical recommendations to optimally manage these common infections in children. Keywords: Abscess, imaging, infection, neck, pediatric, retropharyngeal. OVERVIEW whether purulence is obtained intra-operatively [3]. Classic findings for abscess include large fluid with central A retropharyngeal abscess (RPA) is a deep neck space hypodensity, complete ring enhancement, and scalloping infection defined by its anatomical location within the deep Fig. (1). cervical tissue planes. RPA is located behind the pharyngeal mucosa and is contained anteriorly by the buccopharyngeal fascia (around the constrictor muscles) and laterally by the carotid sheath/parapharyngeal space. Superiorly, it may ex- tend to the skull base, and inferiorly, it can travel to the me- diastinum. This “potential” retropharyngeal space, which expands with infection, is occupied by a lymph-node basin [1] that serves as the common, final drainage pathway of the nasal cavity, paranasal sinuses, nasopharynx, oropharynx, hypopharynx, and larynx. Inadequately treated and virulent infections of these regions can cause suppuration of these nodes. Thus, retropharyngeal lymphadenitis with edema can progress to a cellulitis, which, if untreated, evolves to early abscess or phlegmon and then to abscess. The diagnosis of RPA is initially based upon clinical symptoms and signs on physical examination. What compli- cates this type of deep neck space abscess is the fact that there is rarely any reported visible or palpable external neck swelling. Torticollis, fever, and odynophagia represent a classic triad of symptoms. In addition, there are many pa- tients who have irritability with only subtle findings of head- ache, decreased oral intake, dysphagia, and limited neck mo- tion. As a result, a clinician’s suspicion of RPA is best cor- roborated with computed tomography (CT) imaging with contrast. A CT scan of the neck is helpful to differentiate between retropharyngeal cellulitis, phlegmon, and abscess as well as to localize the infection to facilitate surgical drainage. As such, CT imaging can help determine the next appropriate Fig (1). A 17-year-old boy with trismus, torticollis, and odynophagia. decision in management. The main controversy is in treat- On computed tomography, he was found to have a large retropharyn- ment of abscess with solely medical versus surgical and geal abscess causing narrowing of the airway and displacement of the medical therapy. Shefelbine et al., [2] argue that a CT scan carotid space laterally. Because of its large size, scalloped appear- will help determine what subset of RPA can be successfully ance, and proximity to great vessels, the patient was taken immedi- treated with antibiotics alone. Indeed, a CT scan is helpful as ately for surgical drainage via an intra-oral approach. a surgical roadmap; although, it does not always predict Although airway compromise remains a grave concern, early identification and treatment of a retropharyngeal *Address correspondence to this author at the National Children’s Medical Center, 111 Michigan Avenue, NW, Washington, DC 20010, USA; abscess lessens the rate of this complication. Regardless, Tel: 202-476-3659; Fax: 202-476-5038; E-mail: [email protected] airway monitoring in an intensive care unit (ICU) setting is 2212-3989/12 $58.00+.00 © 2012 Bentham Science Publishers 292 Infectious Disorders – Drug Targets, 2012, Vo l. 12, No. 4 Reilly and Reilly still prudent for large abscesses, young children, and for dren aged 2-6 years put this patient population at highest risk those with frank snoring/stertor; ICU care may be indicated for RPA. also after surgical drainage. In fact, Landler et al. found that the typical patient was a There are two major treatment modalities of retropharyn- five-year-old male from an urban location admitted in a non- geal abscess: 1) conservative medical management with in- elective fashion via the emergency department [4]. travenous antibiotics, sometimes including steroids, and/or Children are much more prone to the development of this 2) prompt surgical drainage. Early stages of infection, gener- condition; although, some adolescents who have either a ally cellulitis or phlegmon, are managed with antibiot- compromised immunological system or who have never had ics/steroid regimens. Advanced or refractory disease leads to a prior adenotonsillectomy can be at risk. Older children are a larger or more serious RPA. True RPA abscesses, which less likely to develop a retropharyngeal abscess because the demonstrate scalloping and measure more than 2 cm in nodes of Rouvière (located in the retropharyngeal space) diameter, or which progress in the setting of antibiotics, typically begin to involute and regress beginning at four favor prompt surgical drainage. years of age; by the time the child is six years old, the retro- Regardless of the treatment modality chosen, an RPA pharyngeal nodes have substantially regressed. Specific geo- requires close monitoring and inpatient hospital care. Chil- graphic regions or ethnic races have never been shown to be dren with an RPA can be managed by the pediatric physi- predisposed to RPA. cians. In coordination with the otolaryngology surgeons, a decision of the benefits of operative intervention should be PRESENTATION/SYMPTOMS made daily. More severely ill patients benefit from infectious disease consultants, who can help select appropriate antibi- Major criteria for probable RPA include toxic appear- otic coverage, evaluate the sensitivity to the antimicrobial ance, airway distress, high grade fever (>101°F), drooling, agent, and determine the length of treatment. dysphagia, trismus, limited neck motion, head tilt or torticol- lis, and noisy breathing pattern including stertor. Patients with milder symptoms, suggestive of cellulitis, are non-toxic INCIDENCE in appearance, possess low grade fever (< 101°F), headache, Antitbiotics have reduced the incidence, morbidity, and irritability, and decreased oral intake. mortality of abscesses. Landler et al., performed the largest Symptoms that occur with an RPA are secondary to the national review in 2003, which showed seasonal variation in swelling of space. Neck stiffness is due to inflammation of admissions for RPA [4]. The highest percentage of admis- prevertebral muscles (i.e., longus colli). Odynophagia is sec- sions was in the spring (March, 10.7%) and lowest in the ondary to distension of the pharynx and hypopharynx. Chil- summer (August, 3.8%). Of the 1,321 national admissions dren usually present three days after developing symptoms, reviewed in this study database there were no deaths. The but can arrive between 24 hours to two weeks after the onset mean age of patients was 5.1 years. Approximately 37% of symptoms. were female and 63% were male. Additionally, a tracheal “rock maneuver” can be per- Kirse et al., showed that group A beta-hemolytic Strepto- formed on physical exam. This manipulation elicits pain coccus (GABS) has been found to be more often present in with movement of the larynx from side to side. Although this cultures during the late 1990s [5]. Because of the increased technique can help rule out RPA, when positive, this is a frequency with which children obtain CT scans, this diagno- relatively non-specific finding. When the RPA abscess is at sis, which was previously missed on exam or lateral neck X- the level of the oropharynx, a bulge of the pharyngeal wall rays, is more readily noted in the current practice of medi- can occasionally be noted with careful examination using a cine. tongue blade and headlight. Small palpable cervical adeno- phathy is common as well. COST Patients often have an antecedent history of pharyngitis, Although there are increased costs associated with failed tonsillitis, adenoiditis, otitis, and/or sinusitis. Although a or prolonged medical treatment, the mortality rate secondary large review by Kirse et al., [5] did not show antecedent to this condition has dramatically fallen to nearly zero in the trauma as the cause of any retopharyngeal abscess, this find- current era of antibiotic medicine. The length of stay of non- ing may be explained by the fact that many children are not surgical patients was on average 3.9 versus 4.8 days. likely to mention trauma. Certainly, children after adenoidec- Landler et al. examined admissions in 2003, and found tomy are at risk if the surgical site becomes infected secon- that less than half, or 563 (43%) patients underwent surgical darily Fig. (2). In addition, specific cases of trans-cervical drainage of their infection [4]. More importantly, the use of spinal surgery with fixation hardware placement or small CT scans and attendant surgical procedures reduces the po- mucosal excoriation from intubation could cause a small tential for spread of RPA. The average cost of treatment in injury