Peritonsillar abscess, also known as quinsy, is a deep neck space infection characterized by a collection of pus in the peritonsillar space.

This infection develops as a suppurative complication of acute tonsillitis or pharyngitis.

As with other deep neck space infections, peritonsillar abscesses are frequently polymicrobial in nature and consist of mouth flora. Some important pathogens to consider when choosing empiric antibiotics include Group A Streptococcus, Staphylococcus aureus, Haemophilus, and Fusobacterium.

Patients present with a muffled voice, fever, sore throat, and dysphagia. There is deviation of the uvula to the unaffected side. Trismus and otalgia may be present. This infection usually affects young adults, but all ages can be affected. Older adults may have subtler symptoms. Laboratory findings include leukocytosis. Treatment consists of antibiotic therapy and surgical drainage.

Complications of this infection include airway obstruction or extension of the infection into contiguous spaces in the neck.