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Peritonsillar and retropharyngeal abscesses are commonly seen in children. The intent of this chapter is to help the clinician establish an accurate diagnosis early and to achieve cure by the judicious and adjunctive use of antibiotics, medical imaging, and surgery.



The pharyngeal tonsils are paired organs that serve as the lateral lymphoid guardians at the posterior aspect of the oropharynx. A peritonsillar abscess (PTA) is an infected collection in the potential space between the palatine tonsil and the superior constrictor muscles. The loose areolar tissue surrounding the tonsils provides a potential space into which infections may spread (Figure 28-1). A PTA usually presents with a collection of purulent fluid at the superior tonsillar pole.1,2

FIGURE 28-1.

Fascial planes of the upper cervical region depicting potential space for peritonsillar abscess formation: (a) peritonsillar space; (b) parapharyngeal space; (c) palatine tonsil; (d) pharyngeal/palatal mucosa; (e) superior constrictor muscle; (f) medial and lateral pterygoid muscles. [Used with permission from Steve Cook, MD.]


The overall incidence of PTA in the total population is estimated to be 3 in 10,000 with the annual incidence in children in the United States estimated to be 0.82–0.94 in 10,000.3,4 Novis et al. reviewed the Kids’ Inpatient Database (KID) from the Agency for Healthcare Research and Quality and found no significant change in the incidence of PTA between 2000 and 2009.3,5 Most children with PTA present in the early teen years, with an average age reported as 13.3 years.3,6


A peritonsillar abscess typically occurs when infectious pharyngotonsillitis progresses from cellulitis to abscess. Streptococcus pyogenes, also known as group A Streptococcus (GAS), is the most commonly cultured organism in non-abscess-associated tonsillitis, isolated in approximately one-third of cases,7,8 but it is not the only bacterial pathogen identified. The majority of organisms causing pharyngotonsillitis are aerobic organisms. However, as infection progresses and abscess pockets form, the oxygen supply decreases, and the microenvironment becomes hospitable to anaerobic bacteria. One study from Japan showed that 58.4% of bacteria isolated from PTAs were anaerobic.8 With the evolution of aerobic to anaerobic species, most PTAs are polymicrobial; GAS, Staphylococcus aureus and Haemophilus influenzae account for most of the aerobic organisms and Prevotella spp., Porphyromonas spp., Fusobacterium spp., and Peptostreptococcus spp. comprise the common anaerobes.2,6,8

Epstein–Barr virus (EBV) causes infectious mononucleosis, which includes pharyngotonsillitis and cervical lymphadenopathy as part of its clinical presentation and, thus, can mimic GAS tonsillitis. The rapid onset of severe tonsillar enlargement seen in EBV can result in tonsillar asymmetry, so careful physical examination is required to differentiate tonsillar asymmetry from ...

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