Peritonsillar Abscess Clinical Presentation

Updated: Jul 25, 2022
  • Author: Benoit J Gosselin, MD, FRCSC; Chief Editor: John Geibel, MD, MSc, DSc, AGAF  more...
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Patients with a peritonsillar abscess (PTA) typically present with a history of acute pharyngitis accompanied by tonsillitis and worsening unilateral pharyngeal discomfort. Patients also may experience malaise, fatigue, and headaches. They often present with a fever and asymmetric throat fullness. Associated halitosis, odynophagia, dysphagia, and a "hot potato–sounding" voice occur.

Many patients present with ipsilateral referred otalgia with swallowing. Trismus (ie, a limitation in the ability to open the oral cavity) of varying severity is present in all cases, reflecting lateral pharyngeal wall and pterygoid musculature inflammation. Because of lymphadenopathy and cervical muscle inflammation, patients often experience neck pain and even a limitation in neck mobility. Clinicians need to be alerted to the diagnosis of a PTA in patients who have pharyngeal symptoms that persist despite an adequate antibiotic regimen.

As the degree of inflammation and infection proceeds, symptoms include progression in the floor of the mouth, the parapharyngeal space, and the prevertebral space. Extension in the floor of the mouth is worrisome because of airway obstruction; the clinician must be aware of an eventual airway emergency.


Physical Examination

The presentation may range from acute tonsillitis with unilateral pharyngeal asymmetry to dehydration and sepsis. Most patients have severe pain. Examination of the oral cavity reveals marked erythema, asymmetry of the soft palate, tonsillar exudation, and contralateral displacement of the uvula (see the image below).

Right peritonsillar abscess. Soft palate, which is Right peritonsillar abscess. Soft palate, which is erythematous and edematous, is displaced anteriorly. Patient has "hot potato–sounding" voice.

Indications for considering the diagnosis of a PTA include the following:

  • Unilateral swelling of the peritonsillar area
  • Unilateral swelling of the soft palate, with anterior displacement of the ipsilateral tonsil
  • Nonresolution of acute tonsillitis, with persistent unilateral tonsillar enlargement

In a retrospective study from the University of Ottawa, Kilty and Gaboury reported that in 50 adults with PTA, clinical signs that had a significant association with the lesion included uvular deviation, trismus, and inferior displacement of the superior pole of the tonsil on the affected side. [7]

A PTA ordinarily is unilateral and located at the superior pole of the affected tonsil, in the supratonsillar fossa. At the level of the supratonsillar fold, the mucosa may appear pale and even show a small pimple. Palpation of the soft palate often reveals an area of fluctuance. Flexible nasopharyngoscopy and laryngoscopy are recommended in patients experiencing airway distress. The laryngoscopy is key to ruling out epiglottitis and supraglottitis, as well as vocal cord pathology.

The degree of trismus depends on the extent of lateral pharyngeal space inflammation. If it is very marked, one should be concerned about possible lateral pharyngeal space cellulitis. The finding of tender ipsilateral cervical lymphadenopathy involving single or multiple nodes is not uncommon. The affected lymph nodes may be quite firm. In presentations with significant nodal inflammation, the patient may experience torticollis and limitation of neck mobility. A more detailed evaluation is essential if suspicion of an accompanying cervical abscess exists.



Numerous clinical complications may occur if the diagnosis of a PTA is missed or delayed. The severity of the complications depends on the rapidity of progression of the illness, as well as the characteristics of the affected fascial spaces. Early management and intervention are important.

The fascial spaces of the neck are interconnected. Once inflammation exceeds the limits of the peritonsillar space, involvement of the masticator space (with increasing degrees of trismus) occurs. Extension may progress to the submandibular and sublingual spaces within the floor of the mouth (Ludwig angina). At this point, emergency airway control through intubation or tracheotomy is indicated to obviate obstruction from swelling of the base of the tongue. In severe cases, death may occur.

Other well-reported complications due to continued progression of the infection may lead to a parapharyngeal abscess, descending necrotizing mediastinitis, Lemierre syndrome, and internal carotid artery pseudoaneurysm. [8, 9, 10, 11]