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Peritonsillar abscess is a complication of acute tonsillitis. Tonsillitis is inflammation of the pharyngeal tonsils (see separate article Tonsillitis). In peritonsillar abscess, there is pus trapped between the tonsillar capsule and the lateral pharyngeal wall.
It usually starts with acute follicular tonsillitis, progresses to peritonsillitis and results in formation of a peritonsillar abscess. It can arise without previous tonsillitis.
An alternative theory suggests involvement of the Weber glands. These are a group of salivary glands, immediately above the tonsillar area in the soft palate. They are thought to play a minor role in clearing any trapped debris from the tonsillar area. Tissue necrosis and formation of pus produce an abscess between the tonsillar capsule, lateral pharyngeal wall and supratonsillar space. There is scarring and obstruction of the ducts that drain the glands. They swell and progress to abscess formation.
- Tonsillitis is predominantly a disease of children. Peritonsillar abscess usually affects teenagers and young adults but can occur in younger children. This picture may, however, be changing. One Israeli study found a distinct cohort of people over 40 suffering from peritonsillar abscess who had more severe symptoms and a more prolonged course. Tonsillitis was not always a precursor to the condition or it sometimes occurred despite prior adequate antibiotic therapy. Smoking was thought to be a risk factor.
- It is most common in November to December and April to May, coinciding with the highest incidence of streptococcal pharyngitis and exudative tonsillitis.
- Culture nearly always shows a mixed flora. Most common organisms include:
- Streptococcus pyogenes (usually the predominant organism).
- Staphylococcus aureus.
- Haemophilus influenzae.
- Anaerobic organisms including Prevotella spp., Porphyromonas spp., Fusobacterium spp. and Peptostreptococcus spp.
- Peritonsillar abscess can also be a complication of infectious mononucleosis.
- Severe throat pain which may become unilateral.
- Drooling of saliva.
- Foul-smelling breath.
- Swallowing may be painful.
- Trismus (difficulty opening the mouth).
- Altered voice quality ('hot potato voice') due to pharyngeal oedema and trismus.
- Earache on the affected side.
- Neck stiffness symptoms.
- Headache and general malaise.
- Examination may be difficult as trismus may make it difficult to open the mouth in up to two thirds of cases.
- Breath is fetid.
- There may be drooling and salivation.
- Look for a temperature.
- Tender, enlarged ipsilateral cervical lymph nodes.
- Torticollis may be present.
- There is unilateral bulging, usually above and lateral to one of the tonsils; occasionally the bulging is inferiorly.
- There is medial or anterior shift of the affected tonsil and the tonsil may be erythematous, enlarged and covered in exudate.
- The uvula is displaced away from the lesion.
- Examine for signs of dehydration.
- Compromise of the airway is rare.
- Spontaneous rupture of the abscess into the pharynx can (rarely) occur and can lead to aspiration.
- The diagnosis is clinical.
- CT scanning is not generally needed but may be used in atypical presentations such as an inferior pole abscess, or if the patient is high risk for a drainage procedure (eg, a bleeding disorder). It may also be helpful to guide drainage in difficult cases.
- One study of a case of peritonsillar abscess with uvular hydrops reported that ultrasound was a helpful investigation.
- Evidence supporting the use of screening for infectious mononucleosis is equivocal. One study found that only 4% of quinsy patients tested positive for infectious mononucleosis, all of them under the age of 30.
- Intravenous fluids may be required to correct dehydration.
- Analgesia should be prescribed.
- Intravenous antibiotics give higher blood levels than oral therapy and are usually used.
- Penicillin, cephalosporins, amoxicillin + clavulanic acid and clindamycin are all appropriate antibiotics. Metronidazole plus penicillin may be helpful in selected cases.
- Intravenous immunoglobulins are sometimes used in rare cases (eg, in association with S. pyogenes infection).
- Studies have also shown that the use of single-dose intravenous steroids as well as antibiotics may be beneficial. They may help to reduce symptoms and to speed recovery.
- One study reported the successful use of intravenous antibiotics and steroids.
- Antibiotics alone are not usually sufficient as treatment. Changes in the microbiology of the causative organisms and their resistance has resulted in surgery being the preferred option in most cases.
- Needle aspiration, incision and drainage and quinsy tonsillectomy are all considered acceptable for the surgical management of acute peritonsillar abscess. An evidence-based review failed to differentiate between them in terms of effectiveness and recurrence rates.
- Ultrasound-guided aspiration is occasionally used if surgery is unsuccessful or the abscess is in a location that is difficult to reach.
- Interval tonsillectomy is usually carried out if there is a background of chronic or recurrent tonsillitis.
- Some surgeons advocate acute (immediate) tonsillectomy as a treatment for peritonsillar abscess. A case series review found no significant differences in total hospital days, blood loss, operative time, or postoperative complications between immediate tonsillectomy and interval tonsillectomy in the treatment of paediatric peritonsillar abscess.
- Tonsillectomy is discussed in more detail in the separate article Tonsillitis.
- The abscess can spread to the deeper neck tissues and can result in necrotising fasciitis. Infection can spread from the parapharyngeal space through the anatomical planes to cause mediastinitis, pericarditis and pleural effusions.
- Airway compromise is rare.
- Recurrence of peritonsillar abscess can occur.
- Haemorrhage may follow tonsillectomy.
- Death can occur from aspiration, airway obstruction, erosion into major blood vessels or extension to the mediastinum.
- The rate of recurrence is poorly defined but is around 9-22%.
- Recurrence can follow tonsillectomy but is rare.
- A Cochrane review found that the benefits of treating sore throats with antibiotics was moderate and that many patients would need to be treated to prevent one case of quinsy. The number needed to treat (NNT) was estimated by a Canadian study as being about 30.
- A fall of 50% in the prescribing of antibiotics to children in English general practice has not been accompanied by an increase in hospital admissions for peritonsillar abscess.
- The guidance regarding antibiotics and sore throat is further discussed in the separate articles Sore Throat and Tonsillitis.
Further reading & references
- Sidell D, Shapiro NL; Acute tonsillitis. Infect Disord Drug Targets. 2012 Aug;12(4):271-6.
- Galioto NJ; Peritonsillar abscess. Am Fam Physician. 2008 Jan 15;77(2):199-202.
- Kordeluk S, Novack L, Puterman M, et al; Relation between peritonsillar infection and acute tonsillitis: myth or reality? Otolaryngol Head Neck Surg. 2011 Dec;145(6):940-5. doi: 10.1177/0194599811415802. Epub 2011 Aug 2.
- Marom T, Cinamon U, Itskoviz D, et al; Changing trends of peritonsillar abscess. Am J Otolaryngol. 2010 May-Jun;31(3):162-7. Epub 2009 Apr 23.
- Zautner AE, Krause M, Stropahl G, et al; Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis. PLoS One. 2010 Mar 1;5(3):e9452. doi: 10.1371/journal.pone.0009452.
- Ryan C, Dutta C, Simo R; Role of screening for infectious mononucleosis in patients admitted with isolated, unilateral peritonsillar abscess. J Laryngol Otol. 2004 May;118(5):362-5.
- Brook I; Microbiology and management of peritonsillar, retropharyngeal, and parapharyngeal abscesses. J Oral Maxillofac Surg. 2004 Dec;62(12):1545-50.
- Sore throat - acute; NICE CKS, October 2012 (UK access only)
- Mills LD, May K, Mihlon F; Peritonsillar abscess with uvular hydrops. West J Emerg Med. 2010 Feb;11(1):83-5.
- Repanos C, Mukherjee P, Alwahab Y; Role of microbiological studies in management of peritonsillar abscess. J Laryngol Otol. 2009 Aug;123(8):877-9. doi: 10.1017/S0022215108004106. Epub 2008 Dec 4.
- Wong S et al; Emerging Microbes and Infections, Nature.com, 2012
- Chau JK, Seikaly HR, Harris JR, et al; Corticosteroids in peritonsillar abscess treatment: a blinded placebo-controlled clinical trial. Laryngoscope. 2014 Jan;124(1):97-103. doi: 10.1002/lary.24283. Epub 2013 Jul 9.
- Pelaz AC, Allende AV, Llorente Pendas JL, et al; Conservative treatment of retropharyngeal and parapharyngeal abscess in children. J Craniofac Surg. 2009 Jul;20(4):1178-81.
- Sowerby LJ, Hussain Z, Husein M; The epidemiology, antibiotic resistance and post-discharge course of peritonsillar abscesses in London, Ontario. J Otolaryngol Head Neck Surg. 2013 Jan 31;42:5. doi: 10.1186/1916-0216-42-5.
- Lin YY, Lee JC; Bilateral peritonsillar abscesses complicating acute tonsillitis. CMAJ. 2011 Aug 9;183(11):1276-9. doi: 10.1503/cmaj.100066. Epub 2011 May 16.
- Costantino TG, Satz WA, Dehnkamp W, et al; Randomized trial comparing intraoral ultrasound to landmark-based needle aspiration in patients with suspected peritonsillar abscess. Acad Emerg Med. 2012 Jun;19(6):626-31. doi: 10.1111/j.1553-2712.2012.01380.x.
- Simon LM, Matijasec JW, Perry AP, et al; Pediatric peritonsillar abscess: Quinsy ie versus interval tonsillectomy. Int J Pediatr Otorhinolaryngol. 2013 Aug;77(8):1355-8. doi: 10.1016/j.ijporl.2013.05.034. Epub 2013 Jun 28.
- Losanoff JE, Missavage AE; Neglected peritonsillar abscess resulting in necrotizing soft tissue infection of the neck and chest wall. Int J Clin Pract. 2005 Dec;59(12):1476-8.
- Collin J, Beasley N; Tonsillitis to mediastinitis. J Laryngol Otol. 2006 Nov;120(11):963-6. Epub 2006 Jul 6.
- Powell J, Wilson JA; An evidence-based review of peritonsillar abscess. Clin Otolaryngol. 2012 Apr;37(2):136-45. doi: 10.1111/j.1749-4486.2012.02452.x.
- Farmer SE, Khatwa MA, Zeitoun HM; Peritonsillar abscess after tonsillectomy: a review of the literature. Ann R Coll Surg Engl. 2011 Jul;93(5):353-5. doi: 10.1308/003588411X579793.
- Spinks A, Glasziou PP, Del Mar CB; Antibiotics for sore throat. Cochrane Database Syst Rev. 2013 Nov 5;11:CD000023.
- Worrall G; Acute sore throat. Can Fam Physician. 2011 Jul;57(7):791-4.
- Sharland M, Kendall H, Yeates D, et al; Antibiotic prescribing in general practice and hospital admissions for peritonsillar abscess, mastoiditis, and rheumatic fever in children: time trend analysis. BMJ. 2005 Aug 6;331(7512):328-9. Epub 2005 Jun 20.
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Dr Michelle Wright
Dr Laurence Knott
Dr Helen Huins