Pediatric Retropharyngeal Abscess Clinical Presentation

• Patients with a retropharyngeal abscess present with constitutional complaints such as fever, chills, malaise, decreased appetite, and irritability.
• Patients may complain of a sore throat, difficulty swallowing (dysphagia), pain on swallowing (odynophagia), jaw stiffness (trismus), or neck stiffness (torticollis). Small children with torticollis tend to hold their neck in a non-neutral position and do not turn their head from side to side.
• Patients may also complain of muffled voice, the sensation of a lump in the throat, and/or pain in the back and shoulders upon swallowing.
• Difficulty breathing may be an ominous complaint that portends impending airway obstruction.
• Patient history is not always straightforward. Signs and symptoms (with decreasing incidence) can include fever, sore throat, dysphagia, trismus, decreased appetite, voice change, odynophagia, neck pain, irritability, and difficulty breathing. A review by Grisaru-Soen et al showed fever (70%) and neck pain (62%) to be the most common symptoms.^[5]
• The course of pharyngeal abscess can be insidious. Sometimes an upper respiratory illness can precede symptoms by weeks. Many patients do not recall (or parents are not aware of) incidences of penetrating trauma. Maintain a high index of suspicion, especially in patients with upper respiratory illnesses that do not appear to resolve in a normal course or with conventional therapy.

• Most patients with a retropharyngeal abscess are febrile. Some appear toxic and irritable.
• Cervical lymphadenopathy, usually unilateral, is the most common physical finding in these patients.
• Patients may have decreased or painful range of motion of their necks or jaws.
• A neck mass or tenderness may be appreciated.
• These patients may present with a muffled "hot potato" voice (dysphonia).
• Upon inspection of the oral cavity, the physician may be able to appreciate a bulge in the posterior pharyngeal wall. Trismus (inability to open the mouth >40 mm from maxillary to mandibular incisors) can be present. As many as 30% of patients have a pharyngeal bulge. It is typically not midline due to the presence of the raphe in the retropharyngeal space caused by the superior constrictor muscle; midline masses are usually in the prevertebral space. Although this mass has been described as fluctuant to palpation, deferring this part of the examination is probably best. This maneuver can lead to abscess rupture and subsequent aspiration. The tracheal rock sign elicits pain while gently moving the larynx and trachea from side to side.
• Patients in respiratory distress or those who present with stridor or drooling have potential airway compromise and should be immediately triaged as such.
• Address vascular complications in the physical examination. Jugular vein thrombophlebitis may manifest as tender induration at the anterior sternocleidomastoid border, vocal cord paralysis, or sepsis of an unknown source. It may also be asymptomatic. Carotid artery rupture can be heralded by sentinel bleeding from the ear, nose, or mouth. Ecchymosis may be detected in the lateral neck.

Most retropharyngeal space infections are spread from various sources in the upper respiratory tract due to the retropharyngeal lymph nodes. The lymphadenitis can form a cellulitis, which suppurate and become an abscess. Possible predisposing infections can include pharyngitis, tonsillitis, otitis, adenitis, adenoiditis, sinusitis, and nasal, salivary, and dental infections. Retropharyngeal infections are also spread from contiguous spaces, such as the parapharyngeal space (eg, abscesses), submandibular space, or prevertebral space (eg, osteomyelitis).

The retropharyngeal space can also be directly inoculated secondary to penetrating trauma. Running and falling down with a sharp object in the mouth is not unusual in children. Because parents may be unaware of these predisposing events, diagnosis is even more elusive. Foreign bodies (for example, fishbones) can become lodged in the posterior pharynx. Although this can happen in the pediatric age group, a foreign body lodged in the posterior pharynx is also a cause of abscess formation in adults.

Deep space infections can be iatrogenic secondary to instrumentation of the upper respiratory tract. All of the following can predispose to abscess formation:

• Laryngoscopy
• Endoscopy
• Esophagoscopy
• Feeding tube insertion
• Endotracheal intubation
• Head and neck surgery
• Dental procedures
• Injections

Risk factors may include low socioeconomic status, poor oral hygiene, immune disfunction (including HIV, diabetes, and immunosuppression)

Bacteria are often polymicrobial, with gram-positive organisms and anaerobes predominating, but gram-negative bacteria have also been isolated. The source is usually oropharyngeal flora. The most common cause is group A beta-hemolytic streptococci. Other nonhemolytic streptococci can be present. Staphylococcus aureus is also fairly common. The most common anaerobes are Bacteroides species. Other causative agents include Haemophilus parainfluenzae and Veillonella, Peptostreptococcus, Fusobacterium, and Eikenella species. The incidence of beta-lactamase production is high. One study noted 22% beta-lactam resistance.

Suspect mycobacterium tuberculosis, B henselae, and coccidiosis in patients who may be predisposed (immunosupression, recent immigrants), especially if they are not responding to more conventional therapy.

Another consideration when evaluating these patients is the possibility of Lemierre syndrome (septic thrombophlebitis of the internal jugular vein from a head and neck infection (eg, retropharyngeal abscess). This infection is classically associated with the Fusobacterium necrophorum, an anaerobic, gram-negative rod.^[6]