Peritonsillar abscessMANAGEMENT

INFECTIOUS DISEASE PRESENTATIONS · 12 SECTIONS

⚲

393 items

☷ Legend

01Approach to the Critical Patient/attcp27

Immediate priorities

›Stabilization priorities

›Airway patency and ability to handle secretions

›Stridor

›Drooling

›Tripod positioning

›Muffled voice

›Hemodynamic status

›Fever with hypotension

›Tachycardia out of proportion to fever

›Sepsis risk

›Altered mental status

›Lactate elevation mmol/l

Airway risk triggers

›Escalation triggers

›If any impending obstruction signs, airway team activation

›Awake fiberoptic approach preferred when feasible

›Surgical airway backup immediately available

›If unable to tolerate oral intake with dehydration, IV route for therapy

›IV fluids for dehydration

›IV analgesia for severe pain

Early consultations

›Consultation and team activation

›ENT or OMFS for drainage planning

›Needle aspiration capability

›Incision and drainage capability

›Consider quinsy tonsillectomy for selected cases

›Anesthesia for anticipated difficult airway

›Trismus limiting laryngoscopy

›Marked oropharyngeal distortion

02History/hx24

Key history elements

›Symptom pattern

›Unilateral severe sore throat

›Rapid progression over 1 to 3 days

›Odynophagia and dysphagia

›Drooling or inability to swallow saliva

›Voice change

›Muffled hot potato voice

›Trismus

›Difficulty opening mouth

›Otalgia referred pain

›Ipsilateral ear pain

Risk factors and pitfalls

›Predisposition and red flags

›Recent tonsillitis or pharyngitis

›Prior antibiotics with persistent unilateral symptoms

›Immunocompromise

›Diabetes

›Steroid therapy

›Chemotherapy

›Deep neck space infection concern

›Neck stiffness or swelling

›Chest pain or dyspnea suggesting mediastinal spread

›Lemierre syndrome concern

›Worsening systemic toxicity

›Pleuritic symptoms after pharyngitis

03Physical Exam/exam29

Oropharyngeal findings

›Local findings

›Peritonsillar swelling and erythema

›Unilateral bulge of soft palate

›Uvular deviation away from affected side

›Midline shift severity

›Tonsillar exudate or fluctuant area

›Visible pus point if spontaneous drainage

›Trismus severity

›Interincisor distance limitation

Airway and systemic findings

›Global assessment

›Work of breathing

›Stridor

›Accessory muscle use

›Hydration

›Dry mucous membranes

›Poor urine output history

›Vital signs

›Fever

›Tachycardia

›Cervical lymphadenopathy

›Tender anterior cervical nodes

PITFALLS

›Missed diagnoses and exam limitations

›Trismus limiting oral exam

›Reexamination after analgesia and IV therapy

›Peritonsillar cellulitis mimicking abscess

›Lack of pus on aspiration

›Retropharyngeal or parapharyngeal infection masquerading as PTA

›Neck swelling

›Limited neck range of motion

04Differential Diagnosis/ddx33

Life threatening diagnoses to exclude

›High risk alternatives

›Epiglottitis

›Rapid progression

›Stridor

›Retropharyngeal abscess

›Neck stiffness

›Bulging posterior pharyngeal wall

›Parapharyngeal abscess

›Neck swelling

›Cranial nerve findings

›Ludwig angina

›Floor of mouth elevation

›Submandibular induration

›Lemierre syndrome

›Internal jugular vein thrombophlebitis

›Septic pulmonary emboli

Mimics and related infections

›Common alternatives

›Acute tonsillitis or pharyngitis

›Bilateral symptoms without uvular deviation

›Infectious mononucleosis

›Hepatosplenomegaly

›Generalized lymphadenopathy

›Dental infection

›Odontogenic pain

›Gingival swelling

›Tumor or peritonsillar mass

›Chronicity

›Weight loss

›Medical coding

›ICD 10 CM J36 peritonsillar abscess

›Use additional code B95 to B98 for infectious agent when known

›SNOMED CT peritonsillar abscess concept

›SNOMED CT 15033003

05Laboratory Tests/lt17

Baseline labs

›Initial laboratory evaluation

›Complete blood count for severity and complications

›Leukocytosis supportive

›Normal value does not exclude abscess

›Electrolytes and renal function for dehydration and dosing

›Hypokalaemia risk with poor intake

›CRP for inflammatory burden and trend

›Limited specificity for abscess vs cellulitis

›Venous lactate mmol/l for suspected sepsis

›Rising value suggests inadequate source control

Microbiology

›Pathogen evaluation

›Throat swab when drainage not immediately available

›Group A streptococcus detection

›Pus culture when aspirate obtained and prior antibiotics or immunocompromise

›Polymicrobial flora including anaerobes

›Blood cultures for systemic toxicity or immunocompromise

›Bacteraemia risk low but clinically important when present

06Diagnostic Tests/dt43

Scoring Systems

›Clinical decision tools

›Centor or McIsaac context for streptococcal pharyngitis

›Not a rule out tool for peritonsillar abscess

›High score supports GAS coverage if treating empirically

›Sepsis screening for toxic appearance

›Use local sepsis pathway for triggers and escalation

MRI

›MRI neck considerations

›Indications

›Suspected deep neck space spread with equivocal CT

›Contrast allergy with high complication concern

›Limitations

›Time to imaging

›Motion artifact with pain and trismus

›Findings to identify

›Parapharyngeal involvement

›Retropharyngeal extension

›CT neck with IV contrast

›Indications

›Uncertain diagnosis after exam and aspiration attempt

›Concern for parapharyngeal or retropharyngeal involvement

›Toxic appearance or atypical course

›Key interpretation targets

›Rim enhancing collection

›Airway narrowing

›Deep neck space spread

›Radiation and contrast considerations

›Pregnancy risk benefit discussion

›Contrast nephropathy risk low with modern protocols

Ultrasound (or US)

›Ultrasound diagnosis support

›Intraoral ultrasound

›Diagnostic performance in studies

›Sensitivity around 90 percent range

›Specificity around 75 to 80 percent range

›Drainage guidance

›Needle trajectory planning

›Depth estimation

›Transcervical ultrasound

›Alternative when trismus limits intraoral probe

›Moderate sensitivity

›Higher specificity than intraoral in some studies

›POCUS workflow pearls

›Distinguish cellulitis vs abscess

›Identify carotid proximity before aspiration

07Disposition/dispo29

Admission criteria

›Inpatient care indications

›Airway concern

›Stridor

›Drooling with inability to manage secretions

›Dehydration or inability to tolerate oral intake

›Persistent vomiting

›Need for IV analgesia

›Systemic toxicity

›Sepsis physiology

›Significant comorbidity

›Immunocompromise

›Poor social supports

›Failed outpatient management

›Progression despite antibiotics

Discharge criteria

›Outpatient management requirements

›Able to swallow liquids after treatment

›Oral antibiotics tolerated

›Airway stable

›No stridor

›No drooling

›Pain controlled with oral regimen

›Analgesic plan provided

›Follow up arranged

›ENT follow up when indicated

Transfer

›Higher level of care triggers

›Anticipated difficult airway without local resources

›Transfer prior to deterioration

›Deep neck space infection on imaging

›Surgical capability required

08Treatment/t99

Source control

›Drainage strategy

›Needle aspiration

›Suitable for most presentations

›Local anesthesia approach

›Diagnostic and therapeutic aspiration

›If no pus obtained

›Peritonsillar cellulitis consideration

›Imaging if persistent concern

›Incision and drainage

›Consider for large collection or recurrence

›ENT preference and experience dependent

›Quinsy tonsillectomy

›Consider for selected cases

›Recurrent peritonsillar abscess

›Airway compromise with need for definitive source control

Antibiotics

›Empiric antimicrobial coverage

›Targets

›Group A streptococcus

›Oral anaerobes

›Polymicrobial flora

›Adult oral regimens when stable after drainage

›Amoxicillin clavulanate

›875 mg by mouth every 12 hours

›Typical duration 10 to 14 days per local protocol

›Penicillin V plus metronidazole

›Penicillin V 500 mg by mouth every 6 hours

›Metronidazole 500 mg by mouth every 8 hours

›Clindamycin for penicillin allergy

›300 to 450 mg by mouth every 6 to 8 hours

›C difficile risk counseling

›Adult IV regimens for admission or severe disease

›Ampicillin sulbactam

›3 g IV every 6 hours

›Transition to oral when swallowing improves

›Ceftriaxone plus metronidazole

›Ceftriaxone 2 g IV every 24 hours

›Metronidazole 500 mg IV every 8 hours

›Clindamycin for severe penicillin allergy

›600 to 900 mg IV every 8 hours

›Consider MRSA coverage only if risk factors

›Pediatrics weight based regimens

›Amoxicillin clavulanate by mouth

›45 mg per kg per day amoxicillin component divided every 12 hours

›Maximum adult dose not exceeded

›Clindamycin by mouth

›10 mg per kg per dose every 8 hours

›Maximum 450 mg per dose

›Ampicillin sulbactam IV

›50 mg per kg per dose ampicillin component every 6 hours

›Maximum adult dose not exceeded

›Evidence grading statement

›Drainage plus antibiotics supported by multiple reviews

›Evidence level consistent with ACEP Level C style consensus for ED practice

Adjuncts

›Corticosteroids

›Symptom relief adjunct

›Reduced pain and faster recovery in some studies

›Single dose approach common

›Adult option

›Dexamethasone 10 mg IV or IM once

›Avoid if uncontrolled diabetes with severe hyperglycaemia risk

›Pediatrics option

›Dexamethasone 0.6 mg per kg IV or IM once

›Maximum 10 mg

›Antiemetics when needed

›Ondansetron

›4 mg IV or by mouth once then as needed

›QT prolongation risk review

Analgesia and hydration

›Pain control

›Paracetamol

›1000 mg by mouth every 6 hours as needed

›Maximum 4000 mg per day

›Ibuprofen

›400 mg by mouth every 6 to 8 hours as needed

›Avoid in significant renal impairment or GI bleed risk

›Opioid sparing escalation when severe

›Short course opioid only if needed

›Sedation risk counseling

›Hydration support

›IV crystalloid for dehydration

›Reassess after bolus

›Urine output improvement

Procedure safety

›Aspiration and drainage precautions

›Bleeding risk review

›Anticoagulant use

›Coagulopathy history

›Anatomy awareness

›Carotid proximity lateral and posterior

›Avoid deep lateral passes

›Local anesthesia considerations

›Topical anesthetic then infiltration

›Aspiration before injection to avoid intravascular delivery

›Post procedure observation

›Airway reassessment

›Oral intake trial after symptom improvement

›Recommendation grading statement

›Airway stabilization and early expert involvement

›Class I recommendation based on expert consensus for high risk airway features

›Drainage when abscess confirmed

›Class IIa recommendation based on expert consensus for source control

09Special Populations/sp30

Pregnancy

›Pregnancy considerations

›Airway edema risk

›Lower threshold for airway team involvement

›Antibiotic selection

›Penicillins and cephalosporins generally preferred

›Avoid tetracyclines

›Clindamycin option for allergy

›Monitor for GI adverse effects

›Imaging selection

›Ultrasound preferred when feasible

›CT only if benefits outweigh fetal radiation risk

Geriatric

›Older adult considerations

›Higher complication risk with comorbidity

›Lower threshold for admission

›Atypical presentation

›Less fever

›More dehydration

›Medication safety

›NSAID renal and GI risk

›Prefer paracetamol first line

Pediatrics

›Pediatric considerations

›Assessment challenges

›Poor exam tolerance

›Ultrasound as adjunct when feasible

›Sedation and airway planning

›Drainage in controlled setting for severe trismus

›Anesthesia support

›Weight based dosing

›Document kg weight

›Maximum adult dose not exceeded

10Background/b22

Epidemiology

›Frequency and demographics

›Most common deep neck infection presentation in many ED settings

›Common in adolescents and young adults

›Incidence estimate reported in UK adult sore throat guidance

›12 per 100000 per year figure cited

Pathophysiology

›Disease mechanism

›Localized pus collection in peritonsillar space

›Between tonsillar capsule and superior pharyngeal constrictor

›Often complication of tonsillitis or peritonsillar cellulitis

›Progression from cellulitis stage

›Polymicrobial infection typical

›Group A streptococcus common aerobic component

›Anaerobes including fusobacterium species possible

Therapeutic Considerations

›Rationale for drainage

›Source control improves pain and swallowing rapidly

›Also confirms diagnosis by pus return

›Rationale for antibiotic spectrum

›Mixed aerobic and anaerobic flora

›Narrow therapy possible in selected cases but broad coverage common

›Rationale for steroid adjunct

›Reduced edema and pain may speed recovery

›Best used after airway risk evaluation

11Patient Discharge Instructions/pdi17

copy discharge instructions

›Home care and return precautions

›Antibiotics exactly as prescribed

›Do not stop early even if improved

›Pain control plan

›Paracetamol and ibuprofen schedule if safe for you

›Hydration goals

›Frequent small sips

›Follow up plan

›ENT or primary care within 24 to 72 hours based on severity

›Return to ED immediately for any of the following

›Trouble breathing

›Noisy breathing or stridor

›Drooling or inability to swallow saliva

›Rapidly worsening throat swelling

›Neck swelling or stiffness

›Persistent fever after 48 hours of antibiotics

›Worsening weakness or fainting

12References/r23

Clinical Guidelines

›Guidance and pathways

›American Academy of Family Physicians review peritonsillar abscess 2017

›Drainage appropriate for most patients

›Broad spectrum antibiotics after drainage targeting GAS and anaerobes

›ENT UK adult acute severe sore throat guideline PDF

›Identifies peritonsillar abscess features and management themes

›Incidence 12 per 100000 cited in guideline

›Merck Manual professional procedure and condition pages

›Drainage methods and antibiotic plus supportive care summary

Evidence Based Sources

›Primary and secondary evidence

›StatPearls peritonsillar abscess NCBI Bookshelf updated 2023

›Empiric antibiotics examples including amoxicillin ampicillin with metronidazole or clindamycin

›Kim DJ et al Academic Emergency Medicine 2023 test characteristics of ultrasound for PTA

›High sensitivity with moderate specificity overall

›Araujo Filho BC et al 2006 intraoral and transcervical ultrasound study

›Intraoral ultrasound sensitivity 95.2 percent specificity 78.5 percent in reported cohort

›Lyon M et al 2005 intraoral ultrasound diagnosis and treatment study

›Supports ultrasound aided diagnosis and drainage safety

Coding Systems

›Standardized terminology

›ICD 10 CM J36 peritonsillar abscess

›Includes quinsy and peritonsillar cellulitis in ICD descriptions

›SNOMED CT 15033003 peritonsillar abscess

›Used in clinical coding summaries

Learn More: Peritonsillar abscess→

Comprehensive Clinical Review

Structured, evidence-informed, long-form analysis for deeper understanding.

Evidence & Review

Reviewed by SymptomDx Medical Team · Last reviewed June 16, 2026

SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.