Parapharyngeal abscess

Olya Polishchuk

Mary Wyers, M.D.

Children's Memorial Hospital


6 year old child with drooling


parapharyngeal abscess, plain film, CT

Publication Date: 2004-07-14


6 year old child with drooling


Plain film: Thickening of retropharyngeal soft tissues from C2 to C7 with anterior displacement of hypopharynx and trachea. This finding persists on the follow up film with extension of the neck.

CT: Ring-enhancing hypodense collection in the left parapharyngeal space with similar smaller collection in the right parapharyngeal space.


Bilateral parapharyngeal abscesses


Phlegmon (no other real differential in the context of fever and drooling)


In young children, infection may spread to the parapharyngeal and retropharyngeal spaces. Infection of these spaces causes pharyngeal swelling. Plain film findings of abscess include thickening of the parapharyngeal and retropharyngeal soft tissues and anterior displacement of the airway. The presence of gas in the abscess, although uncommon, is diagnostic in the absence of acute trauma, foreign body ingestion, and recent surgery. There may be anteroposterior, rotary, or transverse displacement of C1 on C2, or C2 on C3, caused by intense muscle spasm or direct inflammatory ligamentous involvement. Contrast-enhanced CT will demonstrate the location and extent of the disease. Low density fluid collections surrounded by rim enhancement are the key findings in abscesses.

Complications include airway encroachment, osteomyelitis, sinus or orbital involvement, carotid artery rupture, intracranial sepsis, and mediatinal spread.


  1. Kirks, D.R., Griscom, N.T., PRACTICAL PEDIATRIC IMAGING: Diagnostic Radiology of Infants and Children, Lippincott-Raven Publishers, 1998, 246-247.

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