Peritonsillar Abscess



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.

View Image

Right peritonsillar abscess. The soft palate, which is erythematous and edematous, is displaced anteriorly. The patient has a "hot potato–sounding" vo....

View Image

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.

Recent research

In a retrospective cohort study, Marom et al investigated how the characteristics of PTA may have changed over time.[1] 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.[2]

History of the Procedure

Common sites of infection, PTAs have been described as early as the 14th century; however, only since the advent of antibiotics in the 20th century has the condition been described more extensively.


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.

No sexual or racial predilection exists.


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.[3]


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.

Physical examination

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.[4]

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:

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.[4] 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.

Relevant Anatomy

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.

Laboratory Studies

Imaging Studies

Diagnostic Procedures

Medical Therapy

Surgical Therapy

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.

Preoperative Details

Intraoperative Details

Smoking is often more common among patients with peritonsillar abscess and is often associated with more complications.[7] 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

Incision and drainage

Other concerns

Postoperative Details


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.


Outcome and Prognosis

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.

Future and Controversies

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.

Specialty Editors

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.

Chief Editor

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

Disclosure: AMGEN Royalty Consulting; Ardelyx Ownership interest Board membership


  1. Marom T, Cinamon U, Itskoviz D, et al. Changing trends of peritonsillar abscess. Am J Otolaryngol. Apr 22 2009;[View Abstract]
  2. Kordeluk S, Novack L, Puterman M, Kraus M, Joshua BZ. Relation between peritonsillar infection and acute tonsillitis: myth or reality?. Otolaryngol Head Neck Surg. Dec 2011;145(6):940-5. [View Abstract]
  3. Repanos C, Mukherjee P, Alwahab Y. Role of microbiological studies in management of peritonsillar abscess. J Laryngol Otol. Aug 2009;123(8):877-9. [View Abstract]
  4. Kilty SJ, Gaboury I. Clinical predictors of peritonsillar abscess in adults. J Otolaryngol Head Neck Surg. Apr 2008;37(2):165-8. [View Abstract]
  5. Ramirez-Schrempp D, Dorfman DH, Baker WE, Liteplo AS. Ultrasound soft tissue applications in the pediatric emergency department: to drain or not to drain?. Pediatr Emerg Care. Jan 2009;25(1):44-8. [View Abstract]
  6. Ozbek C, Aygenc E, Tuna EU, Selcuk A, Ozdem C. Use of steroids in the treatment of peritonsillar abscess. J Laryngol Otol. Jun 2004;118(6):439-42. [View Abstract]
  7. Marom T, Cinamon U, Itskoviz D, Roth Y. Changing trends of peritonsillar abscess. Am J Otolaryngol. May-Jun 2010;31(3):162-7. [View Abstract]
  8. Heidemann CH, Wallen M, Aakesson M, et al. Post-tonsillectomy hemorrhage: assessment of risk factors with special attention to introduction of coblation technique. Eur Arch Otorhinolaryngol. Jul 2009;266(7):1011-5. [View Abstract]
  9. Thapar A, Tassone P, Bhat N, Pfleiderer A. Parapharyngeal abscess: a life-threatening complication of quinsy. Clin Anat. Jan 2008;21(1):23-6. [View Abstract]
  10. da Silva PS, Waisberg DR. Internal carotid artery pseudoaneurysm with life-threatening epistaxis as a complication of deep neck space infection. Pediatr Emerg Care. May 2011;27(5):422-4. [View Abstract]
  11. Roccia F, Pecorari GC, Oliaro A, et al. Ten years of descending necrotizing mediastinitis: management of 23 cases. J Oral Maxillofac Surg. Sep 2007;65(9):1716-24. [View Abstract]
  12. Apostolopoulos NJ, Nikolopoulos TP, Bairamis TN. Peritonsillar abscess in children. Is incision and drainage an effective management?. Int J Pediatr Otorhinolaryngol. Mar 1995;31(2-3):129-35. [View Abstract]
  13. Baldassari CM, Howell R, Amorn M, et al. Complications in pediatric deep neck space abscesses. Otolaryngol Head Neck Surg. Apr 2011;144(4):592-5. [View Abstract]
  14. Bluestone CD. Current indications for tonsillectomy and adenoidectomy. Ann Otol Rhinol Laryngol Suppl. Jan 1992;155:58-64. [View Abstract]
  15. Brook I. Anaerobic Infections in Childhood. Boston, Mass: G.K. Hall Medical Publisher; 1983:32.
  16. Brook I, Frazier EH, Thompson DH. Aerobic and anaerobic microbiology of peritonsillar abscess. Laryngoscope. Mar 1991;101(3):289-92. [View Abstract]
  17. Buckley AR, Moss EH, Blokmanis A. Diagnosis of peritonsillar abscess: value of intraoral sonography. AJR Am J Roentgenol. Apr 1994;162(4):961-4. [View Abstract]
  18. Ehrenfried Berthelsen R, Hein L. [Lemierre's syndrome following peritonsillar abscess]. Ugeskr Laeger. May 28 2012;174(22):1534-5. [View Abstract]
  19. 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.
  20. Friedman NR, Mitchell RB, Pereira KD, Younis RT, Lazar RH. Peritonsillar abscess in early childhood. Presentation and management. Arch Otolaryngol Head Neck Surg. Jun 1997;123(6):630-2. [View Abstract]
  21. Hanna BC, McMullan R, Hall SJ. Corticosteroids and peritonsillar abscess formation in infectious mononucleosis. J Laryngol Otol. Jun 2004;118(6):459-61. [View Abstract]
  22. Kieff DA, Bhattacharyya N, Siegel NS, Salman SD. Selection of antibiotics after incision and drainage of peritonsillar abscesses. Otolaryngol Head Neck Surg. Jan 1999;120(1):57-61. [View Abstract]
  23. Lyon M, Blaivas M. Intraoral ultrasound in the diagnosis and treatment of suspected peritonsillar abscess in the emergency department. Acad Emerg Med. Jan 2005;12(1):85-8. [View Abstract]
  24. Snow DG, Campbell JB, Morgan DW. The microbiology of peritonsillar sepsis. J Laryngol Otol. Jul 1991;105(7):553-5. [View Abstract]
  25. Strong EB, Woodward PJ, Johnson LP. Intraoral ultrasound evaluation of peritonsillar abscess. Laryngoscope. Aug 1995;105(8 Pt 1):779-82. [View Abstract]
  26. Suskind DL, Park J, Piccirillo JF, Lusk RP, Muntz HR. Conscious sedation: a new approach for peritonsillar abscess drainage in the pediatric population. Arch Otolaryngol Head Neck Surg. Nov 1999;125(11):1197-200. [View Abstract]
  27. Weinberg E, Brodsky L, Stanievich J, Volk M. Needle aspiration of peritonsillar abscess in children. Arch Otolaryngol Head Neck Surg. Feb 1993;119(2):169-72. [View Abstract]

Right peritonsillar abscess. The soft palate, which is erythematous and edematous, is displaced anteriorly. The patient has a "hot potato–sounding" voice.

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.

Right peritonsillar abscess. The soft palate, which is erythematous and edematous, is displaced anteriorly. The patient has a "hot potato–sounding" voice.

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.