Keywords
deep neck space infection, peritonsillar abscess, retropharyngeal abscess, parapharyngeal abscess
A deep neck abscess is a collection of pus in a potential space bounded by fascia. These potential spaces are areas of least resistance to the spread of infection. An infection may begin with a minimal area of cellulitis and progress to a deep neck abscess, which may extend to invade adjacent potential spaces; these spaces frequently encompass vital structures in the neck. Destruction and dysfunction of these structures represent the major complications of deep neck infections.
Epidemiology of Head and Neck Space Infections in Children
Head and neck space infections in children are not uncommon. A survey of members of the American Academy of Otolaryngology found the incidence of peritonsillar abscesses to be approximately 30 per 100,000 person-years, or approximately 45,000 cases annually in the United States and Puerto Rico, whereas a 3-year study in Sweden in a well-defined catchment area of 179,200 inhabitants reported an incidence of 37 per 100,000 person-years. Data from the 2009 Kids’ Inpatient Database (KID) that included data from 2 to 3 million pediatric hospitalizations occurring in 44 states reported an incidence of 9.4 peritonsillar abscesses per 100,000 person-years, 2.2 retropharyngeal abscesses per 100,000 person-years, and 2.0 parapharyngeal abscesses per 100,000 person-years. There was a statistically significant increase in the incidence of retropharyngeal abscesses from 2000 to 2009 (1.0 to 2.2 cases per 100,000 person-years) but there was no change in the incidence of peritonsillar (8.2 to 9.4 cases per 100,000) or parapharyngeal (0.8 to 1.4 cases per 100,000) abscesses. Elsherif and associates described 130 cases of retropharyngeal abscess between 2002 and 2007, and the incidence significantly increased over the study period from 13 cases in 2002 to 44 in 2007. Wright and colleagues also found a doubling in the number of cases of retropharyngeal space infections from 1997 to 2001 versus 2001 to 2005. In contrast, Segal and associates found no increase in the number of peritonsillar infections from 2004 to 2007.
Peritonsillar abscesses rarely occur in young children but most frequently occur in patients in their teens and early 20s. In a 5-year study of 1010 incident head and neck infections, the median (interquartile range) patient age was 13 years for peritonsillar abscesses (range, 9 to 17 years), 2 years for retropharyngeal abscesses (range, 1 to 6 years), and 6 years for parapharyngeal abscesses (range, 5 to 7 years). Retropharyngeal and parapharyngeal abscesses are more common in boys, whereas peritonsillar abscesses occur equally among boys and girls. Retropharyngeal abscesses most commonly occur in the winter and spring, whereas peritonsillar abscesses have been reported to be more common in the autumn and spring and the spring and summer.
Peritonsillar Abscess (Quinsy)
A peritonsillar abscess (quinsy) is circumscribed medially by the fibrous wall of the tonsil capsule and laterally by the superior constrictor muscle. Pus may be localized in the superior pole, midpoint, or inferior pole or rarely may be dispersed, with multiple loculations in the peritonsillar space. The superior pole is the most common location, with a frequency range of 41.2% to 70%; the remaining inferior locations account for the balance.
The etiology of peritonsillar abscesses is not constant. The abscesses may occur after any “virulent” tonsillitis, with extension through the fibrous tonsil capsule. Results of a meta-analysis of 15 previously reported series of patients with peritonsillar abscess reported by Herzon found prior tonsillar infection rates ranging from 11% to 56%, with an overall rate of 36%. Group A β-hemolytic streptococcus has a moderate role in the development of peritonsillar abscesses because throat cultures are only positive in 18% of patients, rapid antigen tests are only positive in 20% to 30% of patients, and abscess cultures demonstrate group A β-hemolytic streptococcus in 46%.
Clinical Manifestations
The patient’s recent history may include a sore throat with occasional unilateral ear pain, malaise, low-grade pyrexia, chills, diaphoresis, dysphagia, reduced oral intake, trismus, and a muffled “hot potato voice.” Trismus results from irritation and reflex spasm of the internal pterygoid muscle. Impaired palatal motion from edema contributes to the muffled voice.
Physical examination reveals minimal to moderate toxicity, dehydration, and drooling. Inspection of the oropharynx may be compromised by trismus. The soft palate is displaced toward the unaffected side, swollen and red, and frequently palpably fluctuant. The edematous uvula is pushed across the midline ( Fig. 11.1 ). The displaced tonsil and its crypts rarely are coated with exudate. The breath is fetid, and ipsilateral, tender, cervical adenopathy is present. The white blood cell count is elevated, with a predominance of polymorphonuclear leukocytes.
Brodsky and associates attempted to identify the clinical signs that might distinguish peritonsillar abscess from peritonsillar cellulitis in a group of 21 children admitted to the Children’s Hospital of Buffalo from 1985 through 1987. No significant difference in age, duration of sore throat, fever, or white blood cell count was noted, although a greater degree of pharyngotonsillar bulge and muffled voice was found in the patients with abscess. Patients with peritonsillar cellulitis improved after receiving 24 hours of intravenous antibiotics, whereas patients with peritonsillar abscess had no change or worsening of symptoms. Blotter and colleagues confirmed these findings in 102 patients admitted to Children’s Hospital of Columbus, Ohio, between 1995 and 1998.
In uncomplicated cases involving adults and older children, computed tomography (CT) has not been as useful as clinical assessment and follow-up evaluation in the management of peritonsillar abscess. CT is useful in young children with suspected peritonsillar abscess who are not cooperative with examination or children with other suspected deep neck infections. In a retrospective study by Baker and associates, CT was ordered in 96 (64.9%) of 148 patients presenting to the emergency department for evaluation of a potential peritonsillar abscess between 2007 and 2009. Recently ultrasonography has been investigated as a tool that avoids undue radiation exposure. Fordham and associates found that transcervical ultrasonography had a sensitivity of 100% and specificity of 76.5% in diagnosing peritonsillar abscess in a study of 43 patients aged 2 through 20 years. While similar results for intraoral ultrasonography has been found in adults, the intraoral route may not be well tolerated in children due to their smaller mouth opening and lack of cooperation.
Treatment
Traditionally management of peritonsillar abscess in children involved hospital admission for intravenous hydration, antibiotic therapy, analgesia, and either intraoral incision and drainage of the abscess or “acute quinsy tonsillectomy” with removal of the medial wall of the abscess. Although older children may tolerate incision and drainage under local anesthetic, the procedure is not well tolerated in young children and carries the risk of potential injury to adjacent vascular structures. The administration of a general anesthetic is required for tonsillectomy in all age groups and often is required for incision and drainage in young children. Acute tonsillectomy often was done to prevent future recurrence of the peritonsillar abscess.
Although it is a commonly accepted clinical observation, a high recurrence rate of peritonsillar abscess has not been well documented. A meta-analysis reported by Herzon of 19 studies from the United States, Europe, and Israel involving 1399 patients found recurrence rates of 10% to 15% for peritonsillar abscess. The rates of recurrence seem to be lower in the United States (0% to 17%) than in the series reported from Europe and Israel (3% to 22%). A retrospective analysis of 290 patients treated for peritonsillar abscess found that patients who had a history of recurrent tonsillitis before development of the abscess had a fourfold greater rate of recurrence than patients with no history (40% vs. 9.6%). The authors recommended that patients with a history of recurrent tonsillitis before admission be treated with tonsillectomy. A nationwide study in Taiwan from 2001 to 2009 involving 28,837 patients found an overall recurrence rate of 5.2%, with a rate of 6.7% in patients younger than 30 years. The rate increased to 13.7% in patients younger than 30 years with five or more prior episodes of tonsillitis compared to 4.4% in those with less than five episodes. Evaluation of 4199 patients with peritonsillar abscess identified in a database of hospital discharge records in Veneto, Italy, found a recurrence rate of 11.7% in patients not initially treated with tonsillectomy. This rate increased to 32% and 40% after the second or third recurrence of the peritonsillar abscess, respectively.
The risks of acute tonsillectomy are not greater than the risks associated with delayed tonsillectomy. In addition, the morbidity caused by two hospitalizations involving two procedures is reduced by acute tonsillectomy. An additional benefit of acute tonsillectomy is the ability to evacuate inferior pole abscesses that technically are difficult to drain by needle aspiration or incision and drainage. Simon and associates found no significant differences in total length of hospital stay, blood loss, operative time, and postoperative complications between 23 children treated by acute quinsy tonsillectomy and 11 children treated with initial antibiotics with or without incision and drainage followed by interval tonsillectomy between 2007 and 2011.
Studies have suggested that many peritonsillar abscesses can be managed by simple needle aspiration combined with antibiotic therapy on an outpatient basis. An extensive meta-analysis of 10 studies conducted from 1961 through 1994 involving 496 patients with peritonsillar abscesses found that needle aspiration had an overall success rate of 94% (range, 85% to 100%). This success rate compares favorably with that reported for incision and drainage. Weinberg and associates successfully performed needle aspiration in 41 of 43 children 7 to 18 years old (mean age, 13.9 years). All were admitted for intravenous antibiotic therapy, 2 (5%) required repeated aspiration for resolution, and 5 (12%) did not respond and required acute tonsillectomy. A pooled analysis of three prospective studies comparing needle aspiration versus incision and drainage showed no significant difference in resolution rates (93.7% for incision and drainage and 91.6% for needle aspiration), but the power was low because of the small sample size. Other studies, which have included adults and children with peritonsillar abscesses, have reported that 0% to 48% of patients require hospitalization.
Younger children often require admission to correct dehydration. Younger children also are more likely than are older children to respond to intravenous antibiotics alone and to have negative findings at surgical drainage. The use of conscious sedation has been reported to be a safe and effective approach for the drainage of peritonsillar abscesses in children.
In a 10-year retrospective review of 83 children with peritonsillar abscesses by Schraff and colleagues, 65% were treated by incision and drainage (51% knife vs. 14% needle aspiration), 31% had quinsy tonsillectomy, and 4% were admitted and treated with intravenous antibiotics alone. Of patients treated surgically, 51% of the procedures were done in the emergency department and 49% were done in the operating room. Forty-eight percent of the children required admission, and the average length of stay was 0.9 days (standard deviation, 1.37 days).
A suggested approach to the management of children with peritonsillar abscess is as follows. Cooperative children should undergo needle aspiration of the abscess and treatment with antibiotics. Children who can tolerate liquids orally may be managed as outpatients, and the remainder should be admitted for hydration and administration of intravenous antibiotics. Approximately 4% of children require a repeated aspiration for resolution. Children who remain symptomatic after undergoing needle aspiration require incision and drainage or acute quinsy tonsillectomy, depending on the prior history of recurrent tonsillitis. Children who cannot tolerate needle aspiration on initial presentation are admitted for administration of intravenous antibiotics. If no response occurs within 24 hours, incision and drainage or acute tonsillectomy is done, depending on the prior history of recurrent tonsillitis. Delayed tonsillectomy is reserved for children who recover from the peritonsillar abscess without general anesthesia but have a history of recurrent tonsillitis or prior peritonsillar abscess.
There are new data suggesting that corticosteroids may be beneficial for patients with peritonsillar abscesses. Ozbek and associates randomized patients aged 16 to 65 years to antibiotics with a single dose of intravenous corticosteroid or antibiotics with a single dose of placebo after needle aspiration. The patients who received corticosteroids demonstrated significant improvements in throat pain, fever, trismus, and hospitalization time compared with control patients. Additional studies in children are needed to support their routine use.
Untreated peritonsillar abscess may point, with spontaneous rupture, or extend to the pterygomaxillary space, with potentially fatal complications. Upper airway obstruction, septicemia, and vascular catastrophe may occur. Necrotizing fasciitis also has been reported in adults with peritonsillar abscess.
Retropharyngeal Abscess (Posterior Visceral Space, Retrovisceral Space, and Retroesophageal Space Abscesses)
The anterior wall of the retropharyngeal space is the middle layer of the deep cervical fascia that abuts the posterior esophageal wall (the superior pharyngeal constrictor muscle). The deep layer of the deep cervical fascia circumscribes the posterior wall of this potential space. Inferiorly, these two fasciae fuse to limit the depth of this pocket at a level between the first and second thoracic vertebrae. A retropharyngeal abscess can erode inferiorly through the junction of these fasciae to extend posteriorly into the prevertebral space ( Fig. 11.2 ). Subsequently, pus in the prevertebral space can descend inferiorly below the diaphragm to the psoas muscles.
The retropharyngeal space contains two paramedial chains of lymph nodes that receive drainage from the nasopharynx, adenoids, posterior paranasal sinuses, middle ear, and eustachian tube. These structures are prominent in early childhood and atrophy at puberty. Retropharyngeal abscesses are common occurrences in young children and are thought to be secondary to suppurative adenitis of these retropharyngeal nodes. Other sources of infection are penetrating foreign bodies, endoscopy, trauma, pharyngitis, vertebral body osteomyelitis, petrositis, dental procedures, and branchial cleft anomalies. In one series of 17 cases of retropharyngeal abscesses at the Children’s Hospital, Denver, Colorado, seven children (41%), including two neonates (most likely associated with attempts at intubation), had perforations of the hypopharynx or esophagus. In a series of 117 children with head and neck space infections treated at the Children’s Hospital of Pittsburgh, 63% of the children with retropharyngeal abscesses had antecedent tonsillitis, pharyngitis, or viral upper respiratory tract infection. Two children had previous trauma; however, no details on the type of trauma were given. In adults, tuberculosis and syphilis were common causes of retropharyngeal abscesses in the preantibiotic era.
Clinical Manifestations
The symptoms of retropharyngeal abscess frequently begin insidiously after mild antecedent infection. Signs and symptoms include sore throat, fever, limitation of neck motion, torticollis, neck pain, neck mass, drooling, odynophagia, poor oral intake, and lethargy. Airway stridor or respiratory distress from edema, cellulitis, or an obstructing mass occasionally occurs. Limited neck motion or torticollis is reported in 50% to 80% of patients. In adults, the symptoms may be milder. Complaints of chest pain may reflect mediastinal extension.
Early in the course, midline or unilateral swelling of the posterior pharynx occurs. Later, gentle palpation may show a large fluctuant mass in the posterior pharynx. Vigorous palpation should be avoided because it may cause the abscess to rupture into the upper airway. As with other abscesses, the white blood cell count is increased, with a predominance of granulocytes.
Plain films of the neck may be performed initially but must be obtained with the patient in a true lateral position, with the neck in extension and on inspiration, or the child’s retropharyngeal soft tissues may appear abnormally thickened. Widening of the prevertebral soft tissues exceeding the anteroposterior diameter of the contiguous vertebral bodies or thickening of the retropharyngeal space greater than 7 mm at C2 in children and adults or 14 mm at C6 in children or 22 mm at C6 in adults suggests retropharyngeal inflammation. Rarely a prevertebral soft tissue mass, air-fluid level, or gas may be seen. The normal cervical lordosis may be lost or reversed secondary to muscle spasm or local inflammation.
CT has rendered the diagnosis and management of deep neck space infections more precise. In contrast to conventional radiologic studies, CT distinguishes cellulitis of the neck, which usually does not require surgical treatment, from a deep neck abscess, which generally does require surgical drainage. With its ability to define differences in tissue density, CT permits an accurate determination of the extent of the abscess and its extension and involvement of adjacent spaces to be made. An abscess is distinguished from cellulitis by a low-attenuation homogeneous area surrounded by a ring enhancement of contrast material ( Fig. 11.3 ). Kirse and Roberson reported scalloping of the abscess wall to be a more useful predictor of the presence of pus than ring enhancement. Freling and colleagues reported that the presence of air within or adjacent to the fluid collection indicated an abscess in all cases. When more than one space is involved, accurate assessment of these spaces may ensure sufficient surgical drainage. Vascular structures can be identified, as can potential complications such as venous thrombosis.
A 10-year retrospective study from the Massachusetts Eye and Ear Infirmary compared preoperative CT scans with intraoperative findings in 38 patients who underwent surgical exploration of the parapharyngeal or retropharyngeal space within 48 hours after the scans were performed. Overall the intraoperative findings confirmed the CT scan interpretation in 76.3% of the patients. Of the 38 patients, five (13.2%) had CT scans indicative of abscesses that were not confirmed at surgery. Exploration of the parapharyngeal or retropharyngeal space revealed cellulitis. The false-negative rate was 10.5%. The sensitivity of CT for detection of parapharyngeal or retropharyngeal space abscess was 87.9%. Additional studies have reported that the accuracy of CT in predicting surgical findings was 63%, 69%, 73%, 76%, 76%, and 92%.
Treatment
The treatment of choice is administration of intravenous antibiotics and incision and drainage. If the mass is small, a peroral incision with the patient in the Rose position (supine with the neck hyperextended) may provide some drainage, but a slight risk of aspiration exists. If the mass is large and extends lateral to the great vessels, or if fever persists after peroral drainage is performed, an external incision is preferred. A tracheotomy may be required if risk of compromising the airway exists. Children may need to be kept intubated postoperatively if there is significant airway obstruction. Martin and associates described four patients treated successfully by CT-guided aspiration of their retropharyngeal abscesses via a percutaneous retromandibular approach in combination with intravenous antibiotics. Three aspirations were performed after failure of surgical drainage, and one was a primary aspiration.
Posterior mediastinitis can result from the spread of infection from the retropharyngeal area into the prevertebral space. The development of mediastinitis has been found to be associated with methicillin-resistant Staphylococcus aureus infection (MRSA), and both mediastinitis and MRSA are more common in children younger than 2 years. Other complications may be seen when the abscess extends to the parapharyngeal space and involves the great vessels and cranial nerves.
Reports have documented that patients with small retropharyngeal abscesses may respond to treatment with intravenous antibiotics alone. Johnston and associates treated 22 of 32 children with retropharyngeal or parapharyngeal abscesses with a trial of at least 24 hours of intravenous antibiotics. Although 13 (59%) ultimately required drainage, 9 (41%) were successfully managed medically. There were no significant differences in age or white blood cell count on admission between the two groups, but children who required drainage had significantly larger abscesses (5.38 vs. 1.53 cm 2 ). Cheng and Elden reviewed 178 children who presented to the Children’s Hospital of Philadelphia from 2007 through 2012 with retropharyngeal or parapharyngeal abscesses. Medical therapy was the initial treatment in 159 (89.3%). Of these 118 (66.3%) were treated successfully while 41 (23.0%) ultimately required surgical drainage. Risk factors for failure of medical therapy were age younger than 51 months, white blood cell count greater than 20,700/mm 3 , intensive care unit admission, CT suggestive of a complete abscess, and abscess size greater than 2.2 cm. A systematic review of eight articles involving 95 patients found a pooled success rate of medical therapy of 52% (95% confidence interval [CI], 53–95%), and when children taken immediately to surgery were excluded, the success rate was 95% (95% CI, 85–100%). Close clinical follow-up is mandatory for children treated with intravenous antibiotics alone. Children who do not improve within 24 to 48 hours require surgical drainage.
Similar results were found in a prospective observational study of 111 children with retropharyngeal infections managed according to a clinical practice guideline between 2001 and 2004 at the Children’s Hospital of Boston. Children were triaged into one of three groups at initial presentation based on clinical symptoms and CT findings: probable cellulitis, probable phlegmon, and probable abscess. Thirty-four (30.6%) children were placed in the abscess pathway and underwent prompt incision and drainage. Frank pus was found in 29 (85.3%), intensive care unit admission was required in 13 (38.2%), and 11 (32.4%) required a peripherally inserted central catheter (PICC) line due to failure to meet discharge criteria on oral antibiotics. Seventy-two (64.9%) patients were placed in the phlegmon group, and all but four required a repeat CT after 48 to 72 hours of antibiotics. Thirty-nine (54.2%) in the phlegmon group ultimately required surgical drainage, and purulence was found in 29 (74.4%). Of the 73 patients who required surgical drainage, 70 were drained transorally, two required an external approach for extension of the abscess lateral to the great vessels, and three had transcervical incisions to drain concurrent but not connected external neck abscesses. Ten patients required repeat drainage in the operating room. Presenting signs or symptoms were not significantly different between surgically and medically managed patients; however surgical patients had higher average white blood cell counts on admission and were more likely to require an intensive care unit admission, less likely to require a PICC line, and had a shorter duration of intravenous antibiotics.
Parapharyngeal Abscess (Pterygomaxillary, Pharyngomaxillary, Lateral, and Pharyngeal Space Abscesses)
The potential parapharyngeal or pterygomaxillary space is an inverted conical cavity (see Fig. 11.2B ) lying along an oblique axis roughly parallel to the ramus of the mandible (see Fig. 11.2C ). The base of the skull at the jugular foramen forms the base of the “cone,” and its apex is at the hyoid bone (see Fig. 11.2B ). The buccopharyngeal fascia, lateral to the superior pharyngeal constrictor, delineates the medial boundary, and the parotid gland and its partially dehiscent deep layer of the superficial cervical fascia form the lateral wall of this cone. The internal pterygoid muscle and mandible demarcate the cone on its anterolateral aspect. The parapharyngeal space is contiguous with the peritonsillar, submandibular, and retropharyngeal spaces, all of which are potential avenues of egress for an extending parapharyngeal space abscess (see Fig. 11.2A ).
The posterior portion of the cone contains the contents of the carotid sheath (carotid artery and internal jugular vein), cranial nerves IX through XII, and the cervical sympathetic chain. The internal pterygoid muscle and fatty connective tissue are anterior.
Involvement of these structures determines the clinical manifestations and complications of the parapharyngeal space abscess. An abscess in the posterior compartment may show medial displacement of the lateral pharyngeal wall and parotid space induration and swelling, with variable overlying facial nerve weakness, carotid artery erosion and hemorrhage, internal jugular vein thrombosis, decreased gag reflex and dysphagia, ipsilateral vocal cord paralysis, weakness of the ipsilateral trapezius muscle, ipsilateral lingual deviation, and Horner syndrome from cervical sympathetic chain involvement.
Extension of the abscess into the anterior compartment causes trismus from irritation of the internal pterygoid muscle. Induration at the angle of the jaw and medial displacement of the tonsil and pharyngeal wall also occur with an anterior compartment abscess.
By the time a patient with an abscess seeks medical attention, the source of the parapharyngeal space infection may be unclear. Reports indicate variable causes, including incompletely or inadequately treated bacterial pharyngitis, tonsillitis, peritonsillar abscess, dental infections, bacterial parotitis, otitis, mastoiditis (Bezold abscess from a mastoid tip infection traveling along the digastric muscles), petrositis, cervical adenitis with suppuration, cervical vertebral tubercular adenitis, foreign bodies, trauma, intravenous drug use, branchial cleft anomalies, and cat-scratch disease. Parapharyngeal abscesses seem to be less common than are peritonsillar and retropharyngeal abscesses in children.
Clinical Manifestations
In addition to the symptoms noted in the preceding description, tender cervical swelling, induration and erythema of the side of the neck, torticollis, sore throat, dysphagia, trismus, hoarseness, malaise, chills, and diaphoresis may occur. Variable low-grade pyrexia with occasional temperature spikes occurs. Examination discloses variable toxicity, respiratory tract distress, laryngeal edema, medial displacement of the lateral pharyngeal wall and inferior tonsil pole, trismus, and, infrequently, drooling. Palpation of the neck reveals a tender, high cervical mass, initially diffuse and later fluctuant. Pharyngeal blood clots may presage erosion of the carotid artery. The complications of parapharyngeal abscesses are related to the structures involved: involvement of the carotid artery can produce hemiplegia from emboli, involvement of the internal jugular vein can lead to internal jugular vein thrombosis, and cephalad extension of the thrombosis may lead to cavernous sinus thrombosis. Internal jugular vein thrombosis is characterized by spiking temperature, toxicity with intense diaphoresis, headaches, and increased intracranial pressure. Septic pulmonary emboli occasionally are present. A pseudoaneurysm of the internal carotid artery may occur as a result of arteritis from contiguous infection and vessel wall erosion. The patient may present with massive epistaxis days or weeks after the initial infection. Treatment involves airway protection, control of the epistaxis, resuscitation, intravenous antibiotics, and surgical ligation or endovascular occlusion.
Extension into the retropharyngeal region by a parapharyngeal abscess may lead to a posterior mediastinitis. Airway obstruction occurring secondary to laryngeal edema and aspiration pneumonia from suppuration of the abscess into the pharynx have been reported. Initially, the parapharyngeal abscess may be difficult to differentiate from a peritonsillar abscess, but the latter usually is less toxic and has a distinct, soft palatal fluctuation.
As described for the diagnosis of retropharyngeal abscess, CT is an extremely useful tool for distinguishing parapharyngeal abscess from cellulitis and for localizing the abscess for surgical planning. Chuang et al. reported that CT had a positive predictive value of 79.6% for a drainable abscess. The CT finding most predictive was a hypodense lesion with a diameter greater than 3 cm, whereas rim enhancement alone was not a good single predictor because its presence depended on the evolution of the abscess. In a review of 47 children who presented with deep neck infections to the Children’s Hospital of Buffalo during a 5.5-year period, CT showed that 34 (77%) of 44 patients who underwent CT had involvement of the parapharyngeal and retropharyngeal spaces. The involvement of both spaces had implications for the approach to surgical drainage.
Treatment
Intravenous antibiotic therapy with incision and drainage is the primary treatment. An otolaryngologic consultation should be obtained for this potentially complex surgery of the neck. The conventional method of approaching this abscess is an external incision with sufficient exposure to provide immediate access to the common carotid artery for ligation should erosion of the carotid artery be present. Intraoperative ultrasonography has been described as a useful modality to assist with external drainage of difficult abscesses located medial to the great vessels and close to the skull base.
An intraoral drainage procedure traditionally has been condemned because rapid access to the vital structures of the neck is impossible with this approach. Nagy and associates used an intraoral approach, however, to treat successfully 21 of 22 children with either parapharyngeal or combined parapharyngeal and retropharyngeal abscesses. The authors emphasized that CT with intravenous contrast enhancement showed that all of the abscesses were located medial to the great vessels and were adjacent to the pharyngeal wall. Amar and Manoukian retrospectively compared 15 children with parapharyngeal abscesses who underwent intraoral drainage with 10 patients who underwent external neck drainage and found no complications or recurrences in either group. The children who underwent intraoral drainage had significantly reduced anesthesia time. The duration of intravenous antibiotics and duration of hospital stay also were shorter in the children who underwent intraoral drainage, but the differences between groups were not statistically significant. Cable and coworkers described 12 children presenting to three centers with superior parapharyngeal space abscesses medial to the great vessels who were treated successfully by intraoral drainage using CT-guided systems to assist with localization of the abscess cavity. Marques and colleagues successfully drained all 11 children presenting with parapharyngeal abscesses over a 5-year period via an intraoral approach with tonsillectomy. A transnasal endoscopic approach had also been used to drain an abscess located near the skull base in a 3-year-old boy.
The use of CT has made it possible for some patients with parapharyngeal abscesses to be managed with intravenous antibiotics. The number of reported cases is small, however, and usually analyzed with cases of retropharyngeal abscess. Nagy and associates used intravenous antibiotics alone to treat three (13%) of 24 children with small parapharyngeal abscesses. Sichel and associates used intravenous antibiotics alone to successfully treat 12 children with infection limited to the parapharyngeal space. Close clinical follow-up is necessary for children with parapharyngeal cellulitis or small parapharyngeal abscesses that are treated conservatively with intravenous antibiotics. Surgical drainage should be performed in children whose infection does not improve within 24 to 48 hours.
In another report, Sichel and colleagues reviewed the CT scans of 29 patients with infections of the parapharyngeal space and divided the patients into two groups: 22 patients with posterior parapharyngeal space infections and seven patients with anterior parapharyngeal space infections. The patients with posterior infections generally were children who responded well to intravenous antibiotics and did not develop complications. The patients with anterior infections of the parapharyngeal space more commonly were adults who required external drainage in addition to intravenous antibiotics and developed complications, including septic shock, respiratory distress, mediastinitis, pericarditis, and lung empyema. The authors suggested that the location of the infection in the fat of the anterior parapharyngeal space resulted in liquefaction of the fat, with formation of pus and rapid spread of the infection to other anatomic spaces.
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