MedPix Medical Image Database COW - Case of the Week Case Contributor: William K Carson Affiliation: Naval Medical Center San Diego

MedPix No: History Pt Demographics: Age = 4 y.o. Gender = boy Four year old boy with 4 day history of sore throat, worse in the last 24 hours. Difficulty swallowing, poor appetite. Parents noticed the patient slobbering for the past several hours prior to ED admission. Downloaded by (-1)

MedPix No: EXAM & LABS Physical exam- markedly erythematous posterior pharynx with pustules, shotty posterior cervical adenopathy.Labs- WBC= 20.5 K ENT Surgical drainage demonstrated retrophargyeal abcess. Throat culture subsequently revealed 4+ Group A Beta Hemmolytic Strep.

Retropharyngeal abscess Conventional Lateral Radiograph: Lateral Cervical Spine shows wide soft-tissue space anterior to spine and significant straightening with loss of normal cervical lordosis. Downloaded by (-1)

FINDINGS Markedly prominent prevertebral soft tissues on c-spine lateral view.

DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? C-Spine trauma (if history correlates) - Mucosal space mass- neoplastic (SCC, NPC, Lymphoma) - Parapharyngeal mass- lipoma, abcess, neoplastic - Retropharyngeal mass- abcess, lymphoma, nodal mets - Prevertebral mass- abcess, osteomyelitis, chordoma -

Diagnosis: Retropharyngeal abscess Dx Confirmed by: ENT surgical visualization and drainage.

DISCUSSION Retropharyngeal abcess formation occurs most commonly in infants and children up to age 14. The abcess may result from pharyngitis (as in this case), pharyngeal trauma, or dental infection. Clinical findings include hyperextension of the neck, gurgling respirations, and puddling of saliva. Complications include rupture with subsequent aspiration and contiguous extension into the posterior mediastinum and lateral pharyngeal space. Typically polymicrobial, the most common causitive bacteria include Strep. pyogenes, Group C Beta- Hemolytic Strep., and Staph. Aureus.