A peritonsillar abscess (PTA) is a localized accumulation of pus in the peritonsillar tissues that forms as a result of suppurative tonsillitis. An alternative explanation is that PTA is an abscess formed in a group of salivary glands in the supratonsillar fossa, known as Weber glands. The nidus of accumulation is located between the capsule of the palatine tonsils and the constrictor muscles of the pharynx. The anterior and posterior pillars, torus tubarius (superior), and pyriform sinus (inferior) form the boundaries of this potential peritonsillar space. Because it is composed of loose connective tissue, severe infection of this area may rapidly lead to formation of purulent material. Progressive inflammation and suppuration may extend to directly involve the soft palate, the lateral wall of the pharynx, and, occasionally, the base of the tongue.
Right peritonsillar abscess. The soft palate, which is erythematous and edematous, is displaced anteriorly. The patient has a "hot potato–sounding" vo....
Pus is aspirated through a wide-bore needle from the right peritonsillar abscess. An additional incision will be made to drain any other pus pockets.
In a retrospective cohort study, Marom et al investigated how the characteristics of PTA may have changed over time. Examining data from 427 patients with PTA, the authors determined that the annual incidence of the condition was approximately 1 patient per 10,000 at the secondary hospital where the cases in the study were treated. PTA demonstrated no sex predilection, nor did it tend to occur more often on a particular side of the body. No seasonal predilection was found.
The cohort included 104 patients (24.4%) aged 40 years or older, with these individuals being more prone to complications and tending to have longer hospital stays than did the younger study patients. No anteceding pharyngotonsillitis was found in 102 patients (24%), and 283 patients (66%) had developed PTA in spite of prior antibiotic treatment. The investigators also found that the percentage of smokers in the cohort was greater than in the general population and that patients with PTA who smoked tended to have more complications than did the other patients.
According to the authors, the above results suggest that PTA tends to affect an older population than before, that its course in older individuals has become longer and worse, and that smoking may be a predisposing factor in its development.
A study by Kordeluk et al looked at the relationship between peritonsillar cellulitis and abscess and outbreaks of acute tonsillitis. Their review of 685 patients, found peaks with seasonal variation for presentations with acute tonsillitis but no association with peritonsillar abscess, which occurred at similar rates throughout the calendar year.
PTA usually is a complication of an acute tonsillitis. Inflammatory edema may lead to significant difficulty in swallowing. Dehydration frequently occurs secondary to the patient's avoidance of painful ingestion of food and liquids. Expansion of the abscess may lead to extension of the inflammation into adjacent fascial compartments of the head and neck, potentially leading to airway obstruction.
The incidence of PTA in the United States is about 30 cases per 100,000 people per year, representing about 45,000 new cases each year. No accurate data are available internationally.
Although tonsillitis is a disease of childhood, only one third of PTA cases are found in this age group. The age of patients with the condition is variable, ranging from 1-76 years, with the highest incidence in persons aged 15-35 years.
Any of the microorganisms that cause acute or chronic tonsillitis may be the causative organisms of a PTA. Most commonly, aerobic and anaerobic gram-positive organisms are identified by culture. Cultures of affected patients reveal group A beta-hemolytic streptococci as most prevalent. Next most commonly, staphylococci, pneumococci, and Haemophilus organisms are found. Finally, other microorganisms that can be cultured include lactobacilli, filamentous forms such as Actinomyces species, micrococci, Neisseria species, diphtheroids, Bacteroides species, and nonsporulating bacteria. Some evidence indicates that anaerobic bacteria frequently cause these infections.
The pathophysiology of PTA is unknown. The most widely accepted theory is the progression of an episode of exudative tonsillitis first into peritonsillitis and then into frank abscess formation. Extension of the inflammatory process may occur in both treated and untreated populations. PTA also has been documented to arise de novo without any prior history of recurrent or chronic tonsillitis. A PTA also can be the presentation of an Epstein-Barr virus (ie, mononucleosis) infection.
Another theory proposes the origin of PTA in Weber glands. These minor salivary glands are found in the peritonsillar space and are thought to help in clearing debris from the tonsils. Should obstruction as a result of scarring from infection occur, tissue necrosis and abscess formation result, leading to PTA.
Patients typically present with a history of acute pharyngitis accompanied by tonsillitis and worsening unilateral pharyngeal discomfort. Patients also may experience malaise, fatigue, and headaches. They often present with a fever and asymmetric throat fullness. Associated halitosis, odynophagia, dysphagia, and a "hot potato–sounding" voice occur.
Many patients present with ipsilateral referred otalgia with swallowing. Trismus (ie, a limitation in the ability to open the oral cavity) of varying severity is present in all cases, reflecting lateral pharyngeal wall and pterygoid musculature inflammation. Because of lymphadenopathy and cervical muscle inflammation, patients often experience neck pain and even a limitation in neck mobility. Clinicians need to be alerted to the diagnosis of a PTA in patients with persisting pharyngeal symptoms despite an adequate antibiotic regimen.
As the degree of inflammation and infection proceeds, symptoms include progression in the floor of the mouth, the parapharyngeal space, and the prevertebral space. Extension in the floor of the mouth is worrisome because of airway obstruction; the clinician must be aware of an eventual airway emergency.
The presentation may vary from acute tonsillitis with unilateral pharyngeal asymmetry to dehydration and sepsis. Most patients have severe pain. Examination of the oral cavity reveals marked erythema, asymmetry of the soft palate, tonsillar exudation, and contralateral displacement of the uvula.
In a retrospective study from the University of Ottawa, Kilty and Gaboury reported that in 50 adults with PTA, clinical signs that had a significant association with the lesion included uvular deviation (p < 0.001), trismus (p < 0.001), and inferior displacement of the superior pole of the tonsil (p < 0.001) on the affected side.
A PTA ordinarily is unilateral and located at the superior pole of the affected tonsil, in the supratonsillar fossa. At the level of the supratonsillar fold, the mucosa may appear pale and even show a small pimple. Palpation of the soft palate often reveals an area of fluctuance. Flexible nasopharyngoscopy and laryngoscopy are recommended in patients experiencing airway distress. The laryngoscopy is key to rule out epiglottitis and supraglottitis, as well as vocal cord pathology.
The degree of trismus depends on the extent of lateral pharyngeal space inflammation. If it is very marked, one should be concerned with the possibility of a lateral pharyngeal space cellulitis. The finding of tender ipsilateral cervical lymphadenopathy involving single or multiple nodes is not uncommon. The affected lymph nodes may be quite firm. In presentations with significant nodal inflammation, the patient may experience torticollis and limitation of neck mobility. A more detailed evaluation is essential if suspicion of an accompanying cervical abscess exists.
Indications for considering the diagnosis of a PTA include the following:
Unilateral swelling of the peritonsillar area
Unilateral swelling of the soft palate, with anterior displacement of the ipsilateral tonsil
Nonresolution of acute tonsillitis, with persistent unilateral tonsillar enlargement
In adults, the clinical signs significantly associated with peritonsillar abscess include trismus, uvular deviation, and inferior displacement of the superior pole of the affected tonsil. In cases of PTA, when incision and drainage (I&D) is performed, it leads to immediate improvement of the patient's symptoms. Needle aspiration may be used as a diagnostic modality and as a therapeutic one, because it allows the accurate localization of the abscess cavity. The aspirated fluid may be sent for culture, and in some cases, an I&D may not be necessary. If patients continue to report recurring and/or chronic sore throats following proper I&D, a tonsillectomy may be indicated.
The palatine tonsils are paired lymphoid organs found between the palatoglossal and palatopharyngeal folds of the oropharynx. They are surrounded by a thin capsule that separates the tonsil from the superior and middle constrictor muscles.
The anterior and posterior pillars form the front and back limits of the peritonsillar space. Superiorly, this potential space is related to the torus tubarius, while inferiorly it is bounded by the pyriform sinus. Composed solely of loose connective tissue, a severe infection may rapidly result in pus formation. The inflammation and suppurative process may extend to involve the soft palate, the lateral wall of the pharynx, and, occasionally, the base of the tongue.
The tonsillar fossa has a rich network of lymphatic vessels leading to the parapharyngeal space and the upper cervical lymph nodes, which explains the pattern of adenopathy observed clinically. Ipsilateral upper cervical lymphadenopathy is the result of the spread of infection to the regional lymphatics. Occasionally, the severity of the suppurative process may lead to a cervical abscess, especially in very fulminant or rapidly progressive cases.
Intraoral drainage has a high rate of success and a low rate of recurrence and morbidity. Normally, unless the patient presents with recurrent tonsillitis or recurrent PTA, tonsillectomy is not indicated. However, in situations in which the abscess is located in an area difficult to access, a tonsillectomy may be the only way to drain the abscess.
CBC count, electrolyte level, blood culture: Patients presenting with PTAs often are septic in appearance and may demonstrate varying degrees of dehydration due to abstention from oral intake. Assessment of these 2 entities should involve the collection of blood for a complete blood count, electrolyte level measurement, and blood cultures.
In patients presenting with tonsillitis and bilateral cervical lymphadenopathy, a Monospot test (heterophile antibodies) should be considered.
If the test results are positive, the patient requires careful evaluation of hepatosplenomegaly. Liver function tests should be considered in patients with hepatomegaly.
Throat culture: To facilitate the identification of infectious organisms, a throat swab and culture are to be considered. The results may assist in selection of the most appropriate antibiotic once the organism is identified, limiting the risk of antibiotic resistance.
Imaging may be particularly useful in cases where an attempt at I&D has failed or where worsening edema in a treated peritonsillar cellulitis is noted. In certain cases, the abscess may be within the tonsil itself and/or partially hidden (ie, inferior or posterior) by the tonsil.
Lateral soft tissue views of the nasopharynx and oropharynx may help the clinician rule out a retropharyngeal abscess.
In the anteroposterior view, the films reveal distortion of soft tissues but are not useful in localizing an abscess.
Computed tomography (CT) scanning
In selected clinical settings and in very young patients, radiological evaluation may be performed with a CT scan of the oral cavity and neck using intravenous contrast enhancement.
Common findings are the presence of a hypodense fluid collection in the apex of the affected tonsil, with peripheral rim enhancement.
Other findings may include an asymmetric enlargement of the tonsils and surrounding fossa.
Further delineation of cervical adenopathy is facilitated, as is the identification of a possible intranodal fluid collection, which indicates a cervical abscess and helps in the planning of surgical management.
Intraoral ultrasonography has been proposed as an imaging modality. It is a simple, well-tolerated, noninvasive technique that can help distinguish between cellulitis and the presence of an abscess.
This also allows the option of a more directed aspiration of the tonsillar fossa before definitive surgical drainage is attempted. One study has shown that this approach is also clinically useful in the evaluation of patients presenting in the emergency department.
A needle aspiration of the abscess site may be performed just prior to attempting the drainage procedure. It allows identification of the location of the abscess in the peritonsillar space.
The aspiration site is anesthetized using lidocaine with epinephrine, and a large-bore (#16- to 18-gauge) needle is mounted on a 10-cc syringe. Infiltration is the method of choice for administering local anesthesia for aspiration and incision of peritonsillar abscesses.
The needle is passed through the anesthetized mucosa where aspiration of the site is performed.
Aspiration of purulent material is diagnostic, and the material may be sent for culture.
Patients with dehydration require intravenous fluid administration until the inflammation resolves and they are able to resume an adequate oral fluid intake.
Antipyretics and analgesics are used to alleviate fever and discomfort.
Oral and parenteral analgesics are an integral part of the management and allow the patient to resume oral intake. Often, the pain relief is so significant from I&D as to allow the patient to resume oral intake with nonnarcotic analgesics.
Antibiotic therapy should begin after cultures are obtained from the abscess. The use of high-dose intravenous penicillin remains a good choice for the empiric treatment of PTA.
Alternatively, due to the polymicrobial nature of cultured pus, agents that treat copathogens and resist beta-lactamases also have been recommended as a first choice.
Cephalexin or other cephalosporins (with or without metronidazole) are likely the best initial option. Alternatives include (1) cefuroxime or cefpodoxime (with or without metronidazole), (2) clindamycin, (3) trovafloxacin, or (4) amoxicillin/clavulanate (if mononucleosis has been ruled out). The patient may be prescribed oral antibiotics once oral intake is tolerated; length of treatment should be 7-10 days.
The use of steroids has been controversial. In a study by Ozbek, the addition of a single dose of intravenous dexamethasone to parenteral antibiotics has been found to significantly lessen the variables of hours hospitalized, throat pain, fever, and trismus compared with a group of patients who were only treated with parenteral antibiotics. In addition, the use of steroids in patients presenting with signs and symptoms of mononucleosis has not led to the formation of a peritonsillar abscess.
The management of patients suspected of a PTA should include a referral to an otolaryngologist or a surgeon with experience in the management of this entity. Early referral should be considered if the diagnosis is unclear and is indicated in patients presenting with airway obstruction.
Smoking is often more common among patients with peritonsillar abscess and is often associated with more complications. Ongoing controversy exists regarding needle aspiration versus I&D as definitive therapeutic modalities. In cooperative patients, procedures may be performed in an examination chair. The supratonsillar fold is anesthetized by either mucosalization or injection of a local anesthetic with epinephrine to reduce bleeding. If injection of a local anesthetic is performed, care should be taken to superficially infiltrate the overlying mucosa and surrounding soft palate.
Needle aspiration can be carried out in children as young as 7 years, especially if conscious sedation is used.
Needle aspiration may be used both as a diagnostic and as a therapeutic modality because it allows the accurate localization of the abscess cavity.
The fluid aspirated may be sent for culture and, in some cases, may not need to be followed by an I&D.
Incision and drainage
Intraoral incision and drainage is performed by incising the mucosa overlying the abscess, usually located in the supratonsillar fold.
Once the abscess is localized, blunt dissection is carried out to break loculations.
The opening is left open to drain, and the patient is asked to gargle with a sodium chloride solution, allowing the accumulated material to exit the abscess cavity.
A successful aspirate or drainage leads to immediate improvement of the patient's symptoms.
In very young or uncooperative patients or when the abscess is located in an unusual location, the procedure is best performed under general anesthesia.
Immediate tonsillectomy as part of the management of a PTA also has been a subject of controversy. Many studies have shown the safety of a tonsillectomy in the setting of an acute abscess. Others have shown that immediate or delayed tonsillectomy may not be necessary because of the high rate of success and low rates of recurrence and morbidity associated with intraoral drainage.
In situations in which the abscess is located in an area difficult to access, a tonsillectomy may be the only way to drain the abscess.
Smoking is often more common among patients with peritonsillar abscess and is often associated with more complications.
Due to the rapid improvement in pain, most patients may be discharged immediately following the procedure if they are able to tolerate oral intake of fluids and bleeding is not apparent.
Some patients may require admission in the hospital setting for 24-48 hours or until oral intake is properly reestablished and pain is well controlled.
Intravenous hydration is important because most patients present with significant fluid deficits.
Continued use of antibiotics in the postoperative period also is important. When the patient is able to take sufficient fluids by mouth, antibiotics may be administered orally for a total length of treatment of 7-10 days.
Oral analgesics also are important due to the level of discomfort from the ongoing inflammation.
Patients are seen routinely in follow-up in the office setting. Elements to consider at that time are reduction of the amount of pain, defervescence, and ability to comfortably resume oral intake.
During the examination, carefully inspecting the drainage site and ruling out re-accumulation of pus is important; check for improvement in tonsillar appearance, inflammation, and the resolution of cervical lymphadenopathy. In general, unless the patient presents with a history of recurring tonsillitis or recurrent PTA, tonsillectomy is not indicated.
For excellent patient education resources, visit eMedicine's Ear, Nose, and Throat Center. Also, see eMedicine's patient education articles Peritonsillar Abscess, Tonsillitis, and Antibiotics.
Numerous clinical complications may occur if the diagnosis of a PTA is missed or delayed. The severity of the complications depends on the rapidity of progression of the illness as well as the characteristics of the affected fascial spaces. Early management and intervention are important.
The fascial spaces of the neck are interconnected. Once inflammation exceeds the limits of the peritonsillar space, involvement of the masticator space (with increasing degrees of trismus) occurs. Extension may progress to the submandibular and sublingual spaces within the floor of the mouth (Ludwig angina). At this point, emergent airway control through intubation or tracheotomy is indicated to obviate obstruction from swelling of the base of the tongue. In severe cases, death may occur.
In patients treated with I&D, evaluating the patency of the opening is important. Premature closure before the cavity has become obliterated is possible, leading to re-accumulation of pus. This may warrant a second I&D procedure or a tonsillectomy.
Limiting the drainage incision to the mucosa of the soft palate and using blunt dissection within the cavity are important to avoid serious bleeding. The terminal branches of the external carotid artery lie on the posterior aspect of the tonsillar fossa and can be injured easily, particularly in children, in whom they are relatively superficial.
Bleeding is a potential complication if branches of the external carotid artery are injured or if the external carotid artery itself is injured. The bleeding may occur intraoperatively or in the early postoperative period.
Intraoperative hemorrhage is an emergency and results from direct injury to terminal branches of the external carotid artery or the external carotid artery itself. Once the patient is stabilized hemodynamically, the tonsillar fossa is reevaluated. The ipsilateral neck also should be prepared and draped in a sterile fashion for access to the proximal external carotid artery. If the hemorrhage is controlled intraorally, the patient's continued stabilization is pursued.
If the bleeding appears to be too brisk, and it is not controlled by careful intraoral source identification, an ipsilateral cervicotomy is performed.
The sternocleidomastoid muscle is retracted laterally, and the carotid sheath contents are identified. The internal jugular vein; the vagus nerve; and the common, external, and internal carotid arteries are identified.
A vascular loop is applied around the external carotid artery to assess temporization of bleeding.
The external carotid artery is dissected superiorly, with careful attention to preservation of the external laryngeal, the ansa hypoglossi, and the hypoglossal nerves.
These severe life-threatening bleeds may require ligation of the external carotid artery.
The general approach to postoperative hemorrhage similarly is directed to the identification of the source of bleeding. The patient is brought to the operating room, and the same procedure as described above is followed.
Other well-reported complications due to continued progression of the infection may lead to a parapharyngeal abscess, descending necrotizing mediastinitis, Lemierre syndrome, and internal carotid artery pseudoaneurysm.[9, 10, 11]
Most patients treated with antibiotics and adequate drainage of their abscess cavity recover within a few days. A small number present with another abscess later, requiring tonsillectomy. If patients continue to report recurring and/or chronic sore throats following proper I&D, a tonsillectomy may be indicated.
Ongoing controversy exists regarding needle aspiration versus I&D as definitive therapeutic modalities.
Immediate tonsillectomy as part of the management of a PTA also has been a subject of controversy. Many studies have demonstrated the safety of a tonsillectomy in the setting of an acute abscess. Others have shown that immediate or delayed tonsillectomy may not be necessary because of the high rate of success and low rates of recurrence and morbidity associated with intraoral drainage. In situations in which the abscess is located in an area difficult to access, a tonsillectomy may be the only way to drain the abscess.
Benoit J Gosselin, MD, FRCSC, Associate Professor of Surgery, Dartmouth Medical School; Director, Comprehensive Head and Neck Oncology Program, Norris Cotton Cancer Center; Staff Otolaryngologist, Division of Otolaryngology-Head and Neck Surgery, Dartmouth-Hitchcock Medical Center
Disclosure: Nothing to disclose.
Brian James Daley, MD, MBA, FACS, FCCP, CNSC, Professor and Program Director, Department of Surgery, Chief, Division of Trauma and Critical Care, University of Tennessee Health Science Center College of Medicine
Disclosure: Nothing to disclose.
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Medscape Salary Employment
Amy L Friedman, MD, Professor of Surgery, Director of Transplantation, State University of New York Upstate Medical University College of Medicine, Syracuse
Disclosure: Nothing to disclose.
Paolo Zamboni, MD, Professor of Surgery, Chief of Day Surgery Unit, Chair of Vascular Diseases Center, University of Ferrara, Italy
Disclosure: Nothing to disclose.
John Geibel, MD, DSc, MA, Vice Chair and Professor, Department of Surgery, Section of Gastrointestinal Medicine, and Department of Cellular and Molecular Physiology, Yale University School of Medicine; Director, Surgical Research, Department of Surgery, Yale-New Haven Hospital
Fairbanks DN. Pocket Guide to Antimicrobial Therapy in Otolaryngology--Head and Neck Surgery. American Academy of Otolaryngology--Head and Neck Surgery. Alexandria, Va: American Academy of Otolaryngology--Head and Neck Surgery; 1999:32-33.