What is the recommended imaging and treatment approach for pediatric patients suspected of having a peritonsillar abscess?

Imaging and Treatment Approach for Peritonsillar Abscess in Pediatric Patients

For pediatric patients with suspected peritonsillar abscess, transcutaneous ultrasound should be used as the initial imaging modality due to its high sensitivity, lack of radiation exposure, and excellent negative predictive value. 1, 2, 3

Diagnostic Imaging Algorithm

First-Line Imaging:

• Transcutaneous ultrasound is recommended as the initial imaging modality for suspected peritonsillar abscess in children 1, 2
• Ultrasound offers 100% sensitivity and 100% negative predictive value for ruling out peritonsillar abscess, making it excellent for identifying patients who will not need surgical intervention 2
• Two approaches can be used: intraoral or transcutaneous, with transcutaneous being preferred in children due to ease of performance 1

Second-Line Imaging (if ultrasound is inconclusive):

• If initial ultrasound results are negative, equivocal, or non-diagnostic and clinical suspicion persists, either CT or MRI should be considered as subsequent imaging 4, 5
• CT imaging should be used more judiciously in pediatric patients due to radiation exposure concerns 6
• MRI is a reasonable alternative when available, though sedation may be required for younger children 4, 5

Imaging Considerations and Caveats

• Ultrasound is operator-dependent and may yield equivocal results, potentially necessitating additional imaging 4, 5
• CT involves radiation exposure, which is particularly concerning in the pediatric population, but may be necessary when ultrasound is inconclusive 4, 5, 6
• Institutions that have implemented policies to reduce radiation exposure have shown significant reductions in CT use for pediatric peritonsillar abscess evaluation 6
• Physical examination alone is not always sufficient to diagnose peritonsillar abscess, making imaging an important diagnostic tool 3

Treatment Approach

For Confirmed Peritonsillar Abscess:

• Needle aspiration or incision and drainage are the two main treatment modalities 7
• Very low-quality evidence suggests that incision and drainage may be associated with a lower chance of recurrence than needle aspiration (RR 3.74,95% CI 1.63 to 8.59) 7
• Some evidence suggests needle aspiration is less painful for patients 7
• Ultrasound can be used for real-time needle guidance during aspiration procedures 3

For Peritonsillar Cellulitis:

• Antimicrobial therapy is the mainstay of treatment 7
• Ultrasound can reliably differentiate between peritonsillar cellulitis and abscess, guiding appropriate management 1, 3

Monitoring and Follow-up

• Patients should be monitored for complications including:
  • Spread of infection to adjacent spaces
  • Airway compromise
  • Dehydration (reported in some patients requiring hospital admission) 7
• Follow-up imaging may be necessary if symptoms persist despite appropriate treatment 5

Key Clinical Pearls

• Transcutaneous ultrasound can detect the spectrum of peritonsillar infections from uncomplicated tonsillitis to frank peritonsillar abscess 1
• There is a statistically significant association between negative ultrasonography and successful medical management, making ultrasound valuable for treatment decision-making 2
• The use of ultrasound as first-line imaging can significantly reduce unnecessary CT scans and radiation exposure in pediatric patients 3, 6