A mother reports that her 4-year-old daughter complains of sore throat and difficulty swallowing for 3 days. She has been irritable and does not want to move her neck. Her appetite and intake have decreased, and she has vomited twice overnight. She exhibits no symptoms of upper respiratory tract infection (URI). She is otherwise healthy with up-to-date immunizations. Her physical examination is remarkable for fever to 102°F (38.9°C), bilateral tonsillar exudates, and an erythematous posterior oropharynx with right posterior pharyngeal wall swelling.
What is the most likely diagnosis?
What is the most appropriate next step in the evaluation?
ANSWERS TO CASE 46: Retropharyngeal Abscess
Summary: An ill-appearing toddler with sore throat, odynophagia, fever, and an abnormal oropharyngeal examination.
• Most likely diagnosis: Retropharyngeal abscess.
• Next step in evaluation: Laboratory testing might include group A beta-hemolytic Streptococcus (GAS) immunoassay and culture. Radiologic evaluation might include lateral cervical x-ray and computed tomography (CT) or magnetic resonance imaging (MRI) to elucidate location and extent of infection.
1. Discuss the diagnosis and treatment of retropharyngeal abscess.
2. Differentiate between various forms of neck abscess.
3. Discuss neck conditions presenting similarly to retropharyngeal abscess.
History and examination for this toddler with odynophagia, fever, and posterior pharyngeal swelling is consistent with retropharyngeal abscess. Because a variety of head and neck lesions can present similarly, the diagnostic challenge lies in determining whether a bacterial infection is present, the extent of infection, the possible need for surgical intervention, and whether the potential exists for spread to surrounding vital structures.
RETROPHARYNGEAL SPACE: Bordered by layers of the deep cervical fascia; located posterior to the esophagus; contains lymphatics draining the middle ears, sinuses, and nasopharynx; contiguous with the posterior mediastinum.
PARAPHARYNGEAL (LATERAL) SPACE: Comprises anterior and posterior compartments containing lymph nodes, cranial nerves, and carotid sheaths; infections in the lateral space can originate from the oropharynx, middle ears, and teeth.
PERITONSILLAR SPACE: Bordered by tonsils and pharyngeal musculature; peritonsillar abscess is typically an extension of acute tonsillitis.
EPIGLOTTITIS: Infection of the cartilaginous structure protecting the airway during swallowing; bacterial etiology (classically Haemophilus influenzae) requiring intravenous antibiotics; fever, drooling, and toxicity are common; emergent airway obstruction is possible.
RAPID STREP IMMUNOASSAY: Detects GAS antigen by latex agglutination or enzyme-linked immunosorbent assay; high specificity and variable sensitivity with false-negative results possible.
MONOSPOT: Latex agglutination of heterophile antibodies to erythrocytes in Epstein-Barr virus (EBV) infection; high specificity and sensitivity in patients older than 3 years; infection may be confirmed by EBV immunoglobulin (Ig)M antibody if heterophile negative.
STRIDOR: Abnormal, musical breathing as a result of large airway obstruction. DYSPHAGIA: Difficulty swallowing.
ODYNOPHAGIA: Pain on swallowing.
TRISMUS: Inability to open the mouth secondary to pain or inflammation or mass effect involving facial neuromusculature.
Categorization of deep neck infections is based on a combination of examination findings and neck imaging. The type and extent of infection ultimately determine whether a patient requires surgery and could be at risk for infection of nearby vital structures, including the mediastinum. Multiple compartments exist within the neck, bordered by musculature and fascia and containing various neurovascular structures (cranial nerves and carotid arteries); infections can easily spread along these fascial planes.
Some age predilections are noted in neck abscess. The typical pediatric patient with retropharyngeal abscess, for example, is a toddler younger than 4 years, coinciding with the time when the majority of URI and otitis cases are seen. Peritonsillar abscess can be seen at any age, but prevalence is greater in the adolescent or young adult. Of all abscess types, peritonsillar abscess is the most common type in the pediatric population.
Infections of the various neck spaces may present similarly. Fever, irritability, and toxicity are common, with patients usually complaining of sore throat, dysphagia, odynophagia, or trismus, with trismus noted more frequently with peritonsillar or parapharyngeal infection. Drooling and increased work of breathing or frank stridoralso can be seen. On examination, neck lymphadenopathy is noted more often in patients with peritonsillar or parapharyngeal abscess. Peritonsillar or soft palatal swelling is more prominent with peritonsillar abscess. A patient who passively refuses to move the neck secondary to pain is likely to have retropharyngeal infection.
Imaging in the patient with suspected neck abscess starts with a lateral cervical x-ray. Radiographic evidence for retropharyngeal abscess on a lateral film includes widening of the retropharyngeal space. Findings on a lateral film in a patient with sore throat and fever may lead to an alternative diagnosis, as in the patient with epiglottic edema and classic “thumb sign” in epiglottitis. Cervical CT imaging is an excellent study for determining whether a patient has only cellulitis and edema surrounding a space, or hypodensity and rim enhancement consistent with an abscess. It also delineates whether there has been extension to contiguous structures. An MRI is an alternative when there is a concern for infection involving a compartment with neurovascular elements and more accurate visualization is desired.
Specific neck space infections have specific origins and complications. Infections involving the teeth, ears, and sinuses may spread to the parapharyngeal space, and may ultimately impact neurovascular elements in the lateral space, either because of erosion or mass effect. Lymph chains draining the sinuses and oropharynx can seed the retropharyngeal space, with potential for spread to the mediastinum, where impact on cardiorespiratory function or mediastinitis could develop. An infection in one compartment can always spread to another. Generally, a neck abscess results when there is contiguous spread of bacteria in a patient with pharyngitis, odontogenic infection, otitis, mastoiditis, sinusitis, or other head and neck infection.
Bacterial etiologies for neck abscess include Streptococcus pyogenes, Staphylococcus sp, Haemophilus influenzae, Peptostreptococcussp, Bacteroides sp, and Fusobacterium sp. Polymicrobial infection is typically seen, often reflective of the organisms most commonly found in infections involving the oropharynx, ear, or sinuses.
Viral etiologies include EBV, cytomegalovirus, adenovirus, and rhinovirus and may present similarly to bacterial infection. Viruses can present with oropharyngeal exudate and swelling or neck masses in the form of lymphadenopathy. A viral process usually can be differentiated from a more concerning bacterial process by ancillary testing previously described and taking into consideration symptomatology more frequently seen in viremia. For example, an exudative pharyngitis with neck findings, rhinorrhea, and cough is more consistent with viral infection.
Standard therapies include intravenous penicillins, advanced-generation cephalosporins, or carbapenems. Clindamycin or metronidazole is added if anaerobes are suspected and broad coverage is desired. Clindamycin often is a good choice for monotherapy in the patient with penicillin allergy. Broad-spectrum antibiotics are started in the patient with neck abscess, with treatment modification if an organism is identified from oropharyngeal or surgical samples. Ultimately, pediatricians and surgeons determine whether to pursue a “watchful waiting” approach with a patient taking antibiotics, or to proceed quickly with needle aspiration or incision and drainage based on infection extent, current impact on surrounding structures, and expectations for progression.
Other abnormalities, unrelated to deep neck infection, also can cause sore throat, odynophagia, or swelling and pain of the oropharynx or neck. They include anatomic variants such as thyroglossal duct cyst or second branchial cleft cyst. Arising from vestigial structures, these cysts can become secondarily infected and develop overlying tenderness and erythema that might be confused with deeper infection. Thyroiditis and sialadenitis also present with fairly localized neck findings. Depending on location, one also should consider thyroid nodule, goiter, or salivary gland tumor, particularly in the case of an initially nontender mass that grows slowly.
46.1 A mother notices a lump on her 5-year-old son’s neck. He complains about pain in the region and difficulty swallowing. Appetite and intake are normal. On examination, he is afebrile with a 3-cm × 3-cm area of mild erythema, fluctuance, and tenderness of the central anterior neck. The mass moves superiorly when he opens his mouth. His oropharynx is clear. Which of the following symptoms was most likely present during the preceding week?
B. Abdominal pain
D. Urinary frequency
46.2 A 9-year-old girl complains of sore throat and anterior neck pain of 1-day duration, and nasal congestion and cough over the past 3 days. There has been no nausea or change in appetite. She describes “lumps growing in her neck” over the past day. Her past medical history is unremarkable. She is afebrile with a clear posterior oropharynx and a supple neck. She has four firm, fixed, and minimally tender submandibular masses without overlying skin changes; the largest mass is 1 cm in diameter. Which of the following is the most likely explanation for these findings?
B. Peritonsillar abscess
C. Retropharyngeal abscess
E. Streptococcal pharyngitis
46.3 A father states that his 7-year-old daughter has a 1-week history of mouth and neck pain. She describes pain on chewing and swallowing. Slight swelling around her right, lower jaw was first noted yesterday. She has been afebrile and exhibits no URI symptoms. Her examination reveals a temperature of 100.22° (37.9°C) with swelling, tenderness, and warmth overlying the right, posterior mandible without fluctuance or skin changes. Scattered, bilateral neck lymphadenopathy is appreciated. Her posterior oropharynx is minimally erythematous, with marked swelling and tenderness of the gum surrounding the posterior molars of the right mandible. Which of the following is the most appropriate next step?
A. Admit her immediately to the hospital for intravenous antibiotics.
B. Commence a broad-spectrum antibiotic and advise her to see a dentist as soon as possible.
C. Obtain an immediate surgery consult.
D. Order a cervical CT and obtain ear, nose, and throat (ENT) consultation today.
E. Perform a rapid strep immunoassay in your clinic.
46.4 A previously healthy, 4-year-old boy has been febrile for a day. He does not want to drink and vomited this morning. There have been no URI symptoms or diarrhea. On examination, he is sleepy, but arousable, and has a temperature of 102.8°F (39.3°C). His posterior oropharynx is markedly erythematous with enlarged, symmetrical, and cryptic tonsils that are laden with exudate. Shoddy cervical lymphadenopathy is noted. He moves his head vigorously in an effort to thwart your examination. Which of the following is the next best step in your evaluation?
A. Lumbar puncture
B. Cervical CT
C. Tonsillar needle aspiration
D. Rapid streptococcal testing
E. Complete blood count
46.1 E. Thyroglossal duct cysts, arising from the embryonic thyroglossal tract, are typically midline, often move on tongue protrusion, and often are noted after a URI. Treatment is usually surgical excision, sometimes after neck CT imaging to ascertain cyst and thyroid anatomy. About half can become infected.
46.2 A. This patient has viral URI symptoms, most likely causing reactive lymph-adenopathy. Supportive care such as analgesics would be a reasonable treatment recommendation. Rapid streptococcal testing usually is not warranted for classic URI symptoms; streptococcal pharyngitis more commonly presents with sore throat, headache, nausea, and/or fever. Signs of viremia and her neck examination do not suggest sialadenitis or neck abscess.
46.3 B. Tooth abscess is her most likely diagnosis, as evidenced by obvious gingival inflammation and other signs of ongoing infection in the area, despite the absence of frank pus from an evident cavity. Potential causative organisms include Streptococcus mutans and Fusobacterium nucleatum. Therapy includes an antibiotic (amoxicillin or clindamycin) and referral to her dentist within the next 24 hours. Deep neck infection is unlikely; imaging and IV antibiotics are not warranted at this time.
46.4 D. This child has a fairly classic examination for streptococcal tonsillitis. The potential for a retropharyngeal or peritonsillar process is diminished by the lack of tonsillar asymmetry, soft palatal changes, and nuchal rigidity. A rapid streptococcal immunoassay would be a good initial test; a swab for culture may be sent as well. Standard therapy would include oral or intramuscular penicillin in the nonallergic patient and an analgesic/antipyretic. If the streptococcal immunoassay is negative, some treat patients whose history and examination are consistent with streptococcal infection while awaiting culture.
Infections involving specific compartments of the neck have specific complications, such as the potential for mediastinitis in the patient with retropharyngeal abscess.
Multiple bacterial and viral etiologies, including GAS and EBV, are possible in the patient with constitutional symptoms and neck findings. Extension of these infections into cervical compartments may endanger surrounding vital structures and potentially require surgery.
Various head and neck abnormalities (infected thyroglossal duct cyst or extensive reactive lymphadenopathy) may mimic deep neck infection.
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