Pediatric Peritonsillar Abscess

Updated: Jan 21, 2022
Author: Itzhak Brook, MD, MSc; Chief Editor: Russell W Steele, MD 


Practice Essentials

Peritonsillar abscess (PTA) is a suppurative infection of the tissues between the capsule of the palatine tonsil and pharyngeal muscles and is the most common abscess of the head and neck region. (See the image below.) It is usually unilateral but can be bilateral in about 6% of instances.[1] Peritonsillar abscess (also known as quinsy) is the commonest of all deep neck infections.[2] Other deep neck infections include retropharyngeal abscess and parapharyngeal (lateral pharyngeal) space abscess.[3]

CT scan with contrast demonstrates a 2-cm low-atte CT scan with contrast demonstrates a 2-cm low-attenuation mass with a minimally enhancing wall in the right peritonsillar region. Associated edema, ipsilateral jugulodigastric lymphadenopathy, compression of the internal jugular vein, and deviation of the airway are present.

Signs and symptoms of peritonsillar abscess

The following clinical features may be noted:

  • Sore throat/dysphagia and neck swelling and pain

  • Trismus

  • Fever

  • Pooling of saliva and drooling

  • Tiredness, irritability, and reduced oral intake

  • Muffled voice

  • Referred ear pain

  • Halitosis

See Presentation for more detail.

Diagnosis of peritonsillar abscess

Laboratory studies

Laboratory tests are unnecessary if the diagnosis of peritonsillar abscess is straightforward. However, tests may include the following.

  • Complete blood cell (CBC) count with differential

  • Serum electrolyte levels

  • Needle aspiration of purulent material for Gram staining and culture and sensitivity

  • Routine throat culture

Imaging studies

Imaging studies are unnecessary if the diagnosis is straightforward; however, a CT scan with intravenous contrast is the preferred radiologic study.

See Workup for more detail.

Management of peritonsillar abscess

Areas to be addressed in patients who present with peritonsillar abscess include hydration, analgesia, and antibiotic therapy.

The three drainage procedures are needle aspiration, incision and drainage, and tonsillectomy.

See Treatment and Medication for more detail.


Peritonsillar abscess generally occurs in the superior pole of the tonsil. It can also be present at the midpoint or inferior pole of the tonsil or have multiple loculations within the peritonsillar space. The development of the abscess is often gradual, with an early stage of peritonsillar cellulitis. If not properly treated, an abscess emerges.

Two mechanisms have been proposed to explain the development of a collection of pus in the loose connective tissue of the supratonsillar fossa. The more common explanation is that a peritonsillar abscess develops from an inadequately treated bacterial tonsillitis. An alternative explanation is that a peritonsillar abscess is an abscess formed in a group of salivary glands in the supratonsillar fossa, known as Weber glands.

Lymphatic drainage from an infected peritonsillar abscess is to the ipsilateral jugulodigastric nodes. Bacterial cultures that are also adequate for the recovery of anaerobic bacteria usually yield polymicrobial aerobic and anaerobic bacteria. Group A beta-hemolytic streptococci is recovered in 25-40% of the abscesses. Anaerobic bacteria is isolated in over 90% of aspirated pus,[4] and elevated antibody levels to these organisms is detected in most patients with peritonsillar abscess.[5] Methicillin-resistant Staphylococcus aureus (MRSA) has been isolated with greater frequency in peritonsillar abscesses in recent years.[6]


Most peritonsillar abscesses are polymicrobial. If appropriate microbiologic techniques are used, a positive culture of aerobic and/or anaerobic pathogens is found in 60-80% of aspirates.[7]

Bacterial growth is often polymicrobial, including aerobic and anaerobic bacteria of oral flora origin. More than half of the aerobic (ie, S aureus) and anaerobic (ie, Prevotella, Porphyromonas, and Fusobacterium species) isolates can be beta-lactamase producers.

Streptococcus pyogenes may be absent in over half the cases, and the causative organisms may be anaerobic bacteria.[8]

Aerobic bacteria implicated in peritonsillar abscess include the following:

  • Group A beta-hemolytic streptococci -S pyogenes most commonly isolated aerobe; other beta-hemolytic streptococci are groups C and G

  • S aureus (methicillin susceptible or methicillin resistant)[9]

  • Alpha-hemolytic streptococci

  • Coagulase-negative staphylococci

  • Streptococcus pneumoniae (penicillin susceptible or penicillin resistant)

Anaerobes implicated in peritonsillar abscess include the following[4, 5] :

  • Anaerobic gram-negative bacilli (eg, pigmented Prevotella and Porphyromonas species, Bacteroides species)

  • Peptostreptococcus species

  • Fusobacterium species (Fusobacterium nucleatum predominated in recent studies)[10]

Viruses do not seem to play a role in the pathogenesis of peritonsillar abscess.[11]

Differentiating between peritonsillar abscess and peritonsillar cellulitis is often difficult because the pathogenesis is similar and patients present with similar symptoms.[12]  Only patients with a peritonsillar abscess require a drainage procedure, whereas patients with either peritonsillar abscess or peritonsillar cellulitis are treated with antibiotics.

Clinical signs such as trismus and inconsistent drooling have been associated more often with peritonsillar abscess. No method to differentiate between the two is perfect; however, current methods include the following:

  • Observing the patient's response to 24-48 hours of intravenous antibiotics

  • Attempting needle aspiration of the site

  • Using an imaging modality such as CT scanning or ultrasonography[13, 14, 15]


United States statistics

The estimated incidence in the United States is 30 cases per 100,000 person-years in patients aged 5-59 years.[16] The incidence in children younger than 18 years is 14 cases per 100,000 population. Approximately 25-30% of patients with peritonsillar abscess are in the pediatric age group.[17]

A study by Qureshi et al analyzed temporal trends in the incidence and surgical management of children with peritonsillar abscesses. The study found that there was no change in the incidence from 2000 to 2009 but there was a change in surgical management, with a significant decrease in the rate of tonsillectomy and significant increase in the rate of incision and drainage procedures.[18]

International statistics

The incidence of peritonsillar abscess in Ontario, Canada, was 12 cases in 100,000 population.[19]

The mean annual incidence of peritonsillar abscess in Europe was 41 cases in 100,000 population.[15]

Race-, sex-, and age-related demographics

No race predilection is known.

No sex predilection is reported.

Peritonsillar abscess most commonly occurs in the third and fourth decades of life. Pediatric cases are more common in children older than 10 years, although cases have been described in children younger than 1 year.


Prognosis is good for full recovery when patients are treated with a combination of a drainage procedure and the appropriate antibiotic therapy. After one aspiration, 80-90% of PTAs resolve. An additional 5-10% of PTAs resolve with repeat aspiration.

If patients have not already undergone an abscess tonsillectomy, PTA is considered as a relative indication for interval tonsillectomy in the following patients:

  • Patients who have had recurrent tonsillitis prior to PTA

  • Patients who have a recurrent PTA

In rare instances, PTA can recur after a bilateral tonsillectomy.


The mortality rate is unknown. Mortality is often due to aspiration of a ruptured abscess or sequelae of sepsis. Morbidity stems principally from pain and dehydration.


Note the following possible complications:

  • Airway compromise

  • Aspiration of abscess contents (spontaneously or with incision and drainage) and development of aspiration pneumonia

  • Parapharyngeal abscess

  • Septic thrombophlebitis involving the internal jugular vein (Lemierre syndrome) or internal carotid artery leading to septicemia with metastatic foci of infection, especially in the lung (Lemierre syndrome, caused by Fusobacterium)

  • Carotid artery rupture

  • Pseudoaneurysm of the carotid artery

  • Sepsis

  • Hemorrhage as a result of iatrogenic injury to major vessels on attempted aspiration or incision and drainage

  • Mediastinitis

  • Necrotizing fasciitis

  • Contiguous spread to the pterygomaxillary space

  • Septic and nonseptic complications of group A streptococcus infection

A literature review conducted by Klug et al revealed that descending mediastinitis was the most frequently reported complication in patients with peritonsillar abscess, followed by parapharyngeal and retropharyngeal abscess, necrotizing fasciitis, and Lemierre syndrome. Overall, 17 different complications were found in the studies examined, with an overall mortality rate of 10%. The researchers also reported that male gender and age over 40 years seemed to be risk factors for complications.[20]

Patient Education

Instruct patients to return for further care with occurrence of the (1) difficulty breathing and/or (2) an inability to tolerate oral intake

For patient education resources, see the WebMD articles Peritonsillar Abscess, Tonsillitis, and Antibiotics.




The following may be noted in patients with peritonsillar abscess (PTA):

  • History of recurrent episodes of pharyngotonsillitis and previous peritonsillar abscess

  • History of snoring or other symptoms of obstructive sleep apnea

  • Sore throat/dysphagia and neck swelling and pain - Usually for 5-7 days; not improving on antibiotics

  • Trismus - Pain when mouth is opened wide; secondary to irritation and reflex spasm of the internal pterygoid muscle

  • Fever

  • Pooling of saliva and drooling

  • Tiredness, irritability, and reduced oral intake

  • Muffled voice - Also called "hot potato" voice; secondary to dysfunction of the palatal muscles on the affected side, resulting in velopharyngeal insufficiency

  • Referred ear pain

  • Smoking - Has been found to be a risk factor in the development of peritonsillar abscess[21]

Peritonsillar abscess may have changed its characteristics in recent years; it is affecting more older patients, has a worse and longer course, and has emerged without antecedent tonsillitis or in spite of prior adequate antibiotic therapy.[22]

Physical Examination

Physical features are as follows[23] :

  • Moderately uncomfortable appearing

  • Febrile

  • Potential respiratory distress

  • Difficulty opening mouth (trismus)

  • Oropharynx symptoms (See the image below for an example of an oropharynx examination.)

    Examination of the oropharynx demonstrates unilate Examination of the oropharynx demonstrates unilateral swelling and erythema of the left tonsil with deviation of the uvula to the contralateral side. Courtesy of Michael Altieri, MD, Medifor, Inc. Used with permission.

    Oropharynx symptoms include the following:

    • Asymmetric swelling of the soft tissues is lateral and superior to the affected tonsil with displacement of the affected tonsil medially and anteriorly. Bilateral peritonsillar abscess is uncommon.

    • Fluctuant area is palpable.

    • Appearance of tonsil may be normal or may show erythema and exudates.

    • Uvula is displaced to the contralateral side.

    • Soft palate is red and swollen.

    • Involvement is bilateral in 3% of cases.

  • Halitosis

  • Cervical and submandibular lymphadenopathy

  • Infection: If epiglottitis or other deep neck space infection are suspected, imaging or careful examination (with the availability of an artificial airway placement) may be required.


Most patients with peritonsillar abscess recover uneventfully after abscess drainage and antibiotic therapy. However, complications can occur and the infection can spread in the upper airway mucosa, through cervical tissues, or hematogenously.[24]  Complications include the following:



Differential Diagnoses



Laboratory Studies

Laboratory tests are unnecessary if the diagnosis of peritonsillar abscess (PTA) is straightforward. However, tests may include the following.

Obtain a complete blood cell (CBC) count with differential. The CBC count may show a leukocytosis with neutrophil predominance. With infectious mononucleosis, expect lymphocyte predominance with atypical lymphocytosis.

Obtain serum electrolyte levels if the patient's oral intake has declined.

Purulent material from needle aspiration should be obtained for Gram stain and culture and sensitivity for aerobic and anaerobic bacteria. Some experts believe this is unnecessary because almost all patients respond following drainage and antibiotic therapy, regardless of culture results. Identifying the organisms and determining their antimicrobial susceptibility are helpful in guiding antimicrobial therapy especially in the presence of complications or extension of infection and in immunocompromised patients. If testing is desired, send material for both aerobic and anaerobic bacteria in appropriate transport media and not on swabs. Culture may be sterile if the patient is currently taking antibiotics.

Obtain also a routine throat culture for group A Streptococcus and blood cultures for aerobic and anaerobic bacteria.

Imaging Studies

Imaging studies are unnecessary if the diagnosis is straightforward.

CT scan with intravenous contrast is the preferred radiological study (see the image below).[25, 26]

CT scan with contrast demonstrates a 2-cm low-atte CT scan with contrast demonstrates a 2-cm low-attenuation mass with a minimally enhancing wall in the right peritonsillar region. Associated edema, ipsilateral jugulodigastric lymphadenopathy, compression of the internal jugular vein, and deviation of the airway are present.

This study is indicated when the diagnosis is unclear, when the patient is uncooperative with the examination, and when the infectious process is thought to involve deeper structures. An abscess appears as a low-attenuation mass with a ring-enhancing wall. Presence of only loss of the fat planes, lack of ring enhancement and soft tissue swelling and edema (but no mass) are consistent with peritonsillar cellulitis.

Ultrasonography is indicated for differentiating between peritonsillitis and peritonsillar abscess.[13, 26, 27] The intraoral approach is more accurate than the transcutaneous approach. However, this may be difficult to perform if trismus is present. Peritonsillar cellulitis manifests a homogeneous or striated area with no distinct fluid collection. Peritonsillar abscess appears as an echo-free cavity with an irregular border. Ultrasonography has a reported sensitivity of 89% and specificity of 100%.



Medical Care

The areas to be addressed in patients with peritonsillar abscess (PTA) include hydration, analgesia, and antibiotics. The mode of delivery (intravenous vs oral) depends on the patient's ability to tolerate oral intake and on the decision to treat the patient as an inpatient or outpatient. 

Hospitalization may be needed, especially in young children. However, adults and older children with uncomplicated peritonsillar abscess may be managed as outpatients after drainage if they can take oral medications and hydration.[16, 17]

Medical treatment alone may be a safe and effective alternative to surgical drainage for the empiric treatment of peritonsillar abscess[28] ; however, careful patient selection is likely to optimize treatment outcomes. 

The initial evaluation of a patient with peritonsillar abscess is the degree of upper airway obstruction. An anxious, ill-appearing child with drooling and posturing must be monitored continuously. When present, airway obstruction may require immediate airway management. Therefore, equipment for intubation cricothyroidotomy or tracheotomy should be available. Supportive therapy to ensure adequate hydration and analgesia should be provided.

Surgical Care

Three drainage procedures are needle aspiration, incision and drainage, and tonsillectomy.

Needle aspiration is performed as follows:

  • This procedure is indicated either as the definitive drainage procedure or to confirm the presence of pus prior to incision and drainage. Ultrasonography may be used to guide the aspiration.

  • The procedure can be done using topical anesthesia. After the identified area of fluctuance is numbed with topical anesthesia (in 90% of cases, this is the superior-medial aspect of the tonsil), an 18-gauge spinal needle is inserted, and pus is aspirated with a 10-mL syringe.

  • Some authorities recommend 3-point aspiration, with the first site being superior and medial and the other 2 sites progressively 0.5-1 cm more inferior and lateral.

  • Complications include respiratory distress, aspiration, and hemorrhage.

  • The success rate of needle aspiration exceeds 90%. Similar success rates were found in randomized trials that compared needle aspiration to incision and drainage (each above 92%).[29, 30] A meta-analysis showed needle aspiration was 94% successful in treating peritonsillar abscess (range, 85-100%).[31]

  • Repeat aspiration may be required in 4-10% of individuals. If symptoms do not resolve with needle aspiration, the patient may either undergo a second needle aspiration or one of the other 2 drainage procedures.

  • Needle aspiration may be performed by a well-trained clinician (usually an otolaryngologist).

  • Contraindications to performing needle aspiration in the outpatient setting are (1) uncertain diagnosis, (2) uncooperative child, (3) very young child, (4) anticipation of airway management problems, and (5) bleeding diathesis.

Incision and drainage is performed as follows:

  • The procedure achieves wider drainage than with needle aspiration.

  • It is more painful than needle aspiration.

  • The procedure requires an otorhinolaryngologist to perform it.

  • Contraindications to performing incision and drainage in the outpatient setting are (1) uncertain diagnosis, (2) uncooperative child, (3) very young child, and (4) anticipation of airway management problems.

Tonsillectomy is performed as follows:

  • When performed in the acute stages of a peritonsillar abscess, the procedure is also known as an abscess tonsillectomy, quinsy tonsillectomy, cold tonsillectomy, and tonsillectomy à chaud. When performed after an interval of several weeks, this procedure is known as interval tonsillectomy.

  • Tonsillectomy is preferred by some authorities because it is definitive therapy, may decrease the overall duration of inpatient stay if interval tonsillectomy is to be performed at a later date, and carries no increased morbidity over interval tonsillectomy.

  • Performed if abscess fails to resolve with other drainage techniques.

  • Tonsillectomy is preferred in those with a previous history of recurrent pharyngitis or previous episodes of peritonsillar abscess.

  • The downsides to this procedure are that it must be performed in the operating room, which leads to increased costs and time delays, and that intubating the patient may prove difficult.

  • Only an otorhinolaryngologist should perform tonsillectomy.


Consult an otorhinolaryngology in all cases for follow-up care.

Directly involve an ear, nose, and throat (ENT) physician in the following cases:

  • All children with an unclear diagnosis

  • Anyone undergoing incision and drainage in the emergency department

  • All patients (very young, uncooperative) who require abscess tonsillectomy in the operating room

Diet and Activity


When airway compromise is a concern, the patient should be restricted to nothing by mouth (NPO). Otherwise, diet should consist of fluids and a soft diet as tolerated.


Permit activity as tolerated.



Guidelines Summary

American Academy of Otolaryngology − Head and Neck Surgery (AAO-HNS): Clinical practice guideline − Tonsillectomy in children, update (2019)[32]



Medication Summary

Drugs used in the treatment of peritonsillar abscess primarily include antibiotics and analgesics. Some otorhinolaryngologists also recommend use of corticosteroids for their anti-inflammatory effect. However, evidence regarding their benefits is inconsistent. Whether these medications are given orally or intravenously depends on whether the patient is able to tolerate orally and whether the patient is being treated as an inpatient or outpatient.

Because the infection is usually polymicrobial aerobic-anaerobic, empiric antimicrobial treatment should include coverage for group A streptococcus, Staphylococcus aureus, and oral flora anaerobes. It can be modified if needed based upon the results of culture or upon the response to treatment. Coverage for methicillin-resistant S aureus (MRSA) is important, especially if drainage is not performed.

Parenteral treatment is given until the patient has no fever and shows clinical improvement. After treatment is converted to oral administration, it should be continued for 14 days.


Class Summary

Empiric intravenous antibiotic therapy should provide coverage for group A Streptococcus, S aureus, and oral flora anaerobes. The initial empiric can be adjusted if necessary based on culture results if drainage is done. Because not all causative organisms are consistently cultured, antimicrobials effective against these organisms is necessary. This mandates providing coverage against polymicrobial aerobic and anaerobic (including beta-lactamase–producing bacteria) pathogens. Beta-lactamase–producing bacteria include Prevotella, Fusobacterium, Haemophilus, and Staphylococcus species.

For outpatient management, a beta-lactam antibiotic is preferred. Amoxicillin plus clavulanate (Augmentin) is the drug of choice (DOC). For inpatient management, intravenous ampicillin plus sulbactam is preferred. Alternatively, a combination of intravenous ceftriaxone and clindamycin or a carbapenem (ie, imipenem, meropenem) is used for severe or complicated cases. Coverage for methicillin-resistant Staphylococcus aureus (MRSA) includes clindamycin, vancomycin, or linezolid.[33]

Amoxicillin plus clavulanate (Augmentin)

Interferes with synthesis of cell wall peptidoglycan during active replication, resulting in bactericidal activity against susceptible microorganisms. Clavulanic acid is a potent beta-lactamase inhibitor, further broadening the spectrum of activity to include beta-lactamase–producing S aureus and anaerobes (eg, Prevotella species).

For children >3 months, base dosing protocol on amoxicillin content. Because of different amoxicillin/clavulanic acid ratios in 250-mg tab (250/125) vs 250 mg chewable-tab (250/62.5), do not use 250-mg tab until child weighs >40 kg.

Imipenem and cilastatin (Primaxin)

For treatment of multiple organism infections in which other agents do not have wide spectrum coverage or are contraindicated due to potential for toxicity. Provides anaerobic coverage.

Ampicillin plus sulbactam (Unasyn)

Interferes with synthesis of cell wall peptidoglycan during active replication, resulting in bactericidal activity against susceptible microorganisms. Clavulanic acid is a potent beta-lactamase inhibitor, further broadening the spectrum of activity to include beta-lactamase–producing S aureus and anaerobes (eg, Prevotella species).

Clindamycin (Cleocin)

Alternative agent in patients allergic to penicillin. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.

Ceftriaxone (Rocephin)

Third-generation cephalosporin with broad-spectrum, gram-negative activity; lower efficacy against gram-positive organisms; higher efficacy against resistant organisms. Bactericidal activity results from inhibiting cell wall synthesis by binding to one or more penicillin binding proteins. Exerts antimicrobial effect by interfering with synthesis of peptidoglycan, a major structural component of bacterial cell wall. Bacteria eventually lyse due to the ongoing activity of cell wall autolytic enzymes while cell wall assembly is arrested.

Highly stable in presence of beta-lactamases, both penicillinase and cephalosporinase, of gram-negative and gram-positive bacteria. Approximately 33-67% of dose excreted unchanged in urine, and remainder secreted in bile and ultimately in feces as microbiologically inactive compounds. Reversibly binds to human plasma proteins, and binding have been reported to decrease from 95% bound at plasma concentrations < 25 mcg/mL to 85% bound at 300 mcg/mL.

Vancomycin (Vancocin)

Potent antibiotic directed against gram-positive organisms and active against Enterococcus species. Useful in the treatment of septicemia and skin structure infections. Indicated for patients who are unable to receive or who have not responded to penicillins and cephalosporins or for infections with resistant staphylococci. Use creatinine clearance to adjust dose in patients diagnosed with renal impairment.

Linezolid (Zyvox)

Prevents formation of functional 70S initiation complex, which is essential for bacterial translation process. Bacteriostatic against staphylococci.

Analgesic agents

Class Summary

Pain control is essential to quality patient care.

Codeine/acetaminophen (Tylenol with Codeine Elixir)

Indicated for the treatment of mild to moderate pain. Contains codeine 12 mg and acetaminophen 120 mg per 5 mL.



Further Outpatient Care

Arrange for follow-up in 24 hours.

Arrange for patient reassessment for further surgical intervention such as elective tonsillectomy.

Further Inpatient Care

Admit patients with peritonsillar abscesses (PTAs) with the following conditions:

  • Airway compromise

  • Dehydration and inability to tolerate oral intake

  • Uncertain outpatient compliance

  • Unclear diagnosis

  • Suspected local or systemic complications

  • Toxic appearance

Include intravenous fluids, intravenous antibiotics, and analgesia.

Reevaluate patients daily for possible further surgical intervention including repeat aspiration, incision and drainage, or abscess tonsillectomy in the operating room.


Transfer to an institution where ENT has experience in treating peritonsillar abscess in children.


Adequate antimicrobial treatment of group A Streptococcus tonsillitis may reduce the risk of peritonsillar abscess. In patients with peritonsillar abscess who have a history of recurrent tonsillitis or peritonsillar abscess, interval tonsillectomy is recommended to prevent further episodes.

Poor oral hygiene, inappropriate antibiotic use, and smoking all are risk factors for peritonsillar abscess in adults,[34, 35] and eliminating these risk factors may reduce its occurrence.