Deep fascial space infection of the neck: a continuing challenge.

Abstract: We present our clinical experience with two complex cases of deep fascial space infections of the neck. The first was a case of cervical necrotizing fasciitis involving the submental space. The second was an infection beginning at the soft palate and extending to the anterior mediastinum. Both infections emanated from an oral source in patients with diabetes mellitus, and both patients required multiple surgical debridements and endotracheal intubation for airway protection. Despite the declining incidence of deep space neck infections, our cases illustrate the challenging diagnostic and treatment dilemmas for the clinician managing patients with diabetes.

**********

Life-threatening infections of the deep fascial space of the head and neck are usually odontogenic. These suppurative processes can also arise as complications of infections of the salivary glands, the epiglottis, hard and soft palate, tonsils, and retropharynx. (1,2) Infections of the deep fascial spaces of the neck are ominous because of the propensity of bacteria to spread hematogenously and contiguously along the fascial planes to involve the anterior mediastinum, pleuropulmonary spaces, retropharyngeal space, prevertebral spaces, "danger" space, and the heart valves. Recognized risk factors of deep neck space infections include dentoalveolar abscesses, neck trauma, endotracheal intubation, traumatic foreign body ingestion, and IV drug abuse. (1,3) In one study, 56% of the deep space neck infections involving the retropharynx were idiopathic. (3,4)

We present two cases of deep fascial space infections of the neck that occurred at our institution during the past year. The first was a case of cervical necrotizing fasciitis involving the submental space, and the second began as a case of cellulitis of the soft palate that evolved into pyogenic anterior mediastinitis. Both infections emanated from an oropharyngeal source in patients with diabetes who required multiple surgical debridements and endotracheal intubation for airway protection. Despite the declining incidence of deep space infections, these illustrative cases are a reminder of the complexity inherent in the management of these entities in patients with diabetes.

Case Reports

Patient 1

A 55-year-old man with diabetes mellitus type 1 went to his local hospital's emergency department (ED) because of right-sided neck pain and swelling. He admitted to having self-extracted two maxillary molars and one mandibular molar with pliers 3 days earlier. After an unremarkable oral examination in the ED, he was instructed to take clindamycin 150 mg qid for 10 days. Three days later, he returned to the ED with fever and a draining necrotic area beneath the right mandible surrounded by an extensive area of warmth and erythema of the neck (Fig. 1). His peripheral white blood cell count was 24,100/[mm.sup.3] and the Westergren erythrocyte sedimentation rate was 123 mm/h. Aerobic and anaerobic cultures of the drainage did not yield a pathogen, He was promptly treated with IV ampicillin/sulbactam and clindamycin and transferred to our regional hospital.

At arrival, the patient was intubated. Because of the extreme nature of this infection, he had extensive serial surgical fascial debridements (Fig. 2). Intraoperative cultures from the first surgical debridement grew Peptostreptococcus species and microaerophilic streptococci. Surgical exploration showed infection extending from the oral cavity to the submandibular and submental spaces, and a clinical diagnosis of cervical necrotizing fasciitis was made. The entire anterior aspect of his cervical fascia from the chin to the sternal notch was excised (Fig. 2). The antero-inferior aspect of the right mandible was also exposed. Ampicillin/sulbactam was continued for an additional 4 weeks. On hospital Day 16, he had split-thickness skin grafting to the debrided area. On Day 22, he was extubated. Because of the concern for mandibular osteomyelitis as a complication of cervical necrotizing fasciitis, a prolonged course of antibiotics was prescribed. He was discharged with a regimen of oral amoxicillin/clavulanic acid for 6 weeks (total of 10 weeks of antibiotic therapy). At follow-up visits, the skin graft was completely intact, without evidence of breakdown or fistula formation; there was no mandibular tenderness.

[FIGURE 2 OMITTED]

Patient 2

A 54-year-old black man with a history of diabetes mellitus went to an ED because of a sore throat. Physical examination revealed only mild erythema of the soft palate. A clinical diagnosis of palatal cellulitis was made. No throat culture was performed, but he was treated with a single IM benzathine penicillin injection (1.2 million U). The patient returned to the ED 2 days later with increased soreness of his throat, fever, systemic toxicity, and hyperglycemia. Laryngoscopic examination revealed progressive palatal inflammation and epiglottitis. The patient was admitted to the hospital.

On physical examination, the patient was anxious, in extremis, and unable to swallow. His temperature was 38.7[degrees]C (101.7[degrees]F). Within 1 day, diffuse swelling of the neck developed, with extensive cutaneous erythema and severe lymphadenitis. Repeated oral examination showed extensive mucosal erythema and a large amount of pus tracking from the soft palate into the retropharyngeal tissues and periepiglottic folds. The anterior cervical swelling and erythema now extended to the upper chest. The peripheral white blood cell count was 12,400/[mm.sup.3]. Computed tomographic (CT) scan of the neck showed diffuse air pockets in and around all the deep spaces of the neck (Fig. 3). No evidence of a branchial cleft cyst or jugular vein thrombosis was present. IV antibiotic therapy was started (ampicillin/sulbactam), and immediate surgical debridement was performed transorally. Culture of the purulent drainage in the patient's mouth grew multiple organisms (Klebsiella pneumoniae, Lactobacillus species, and a-hemolytic streptococci; no evidence of Group A [beta]-hemolytic streptococci was found). A follow-up CT scan showed diffuse soft tissue edema and fluid collection in the upper part of the anterior mediastinum and bilateral pleural effusions (Fig. 4). Mediastinoscopy-guided drainage of the fluid collection was performed in concert with another extensive surgical debridment, Mediastinal fluid cultures were negative. The patient remained intubated for 3 weeks because of severe soft tissue inflammation and edema. A prolonged course of IV ampicillin/sulbactam was followed by a course of oral amoxicillin/clavulanic acid.

[FIGURE 3-4 OMITTED]

Discussion

These two cases are examples of fulminant deep space neck infections in patients with diabetes. Both cases began as oropharyngeal infections that are routinely managed in the ambulatory setting. Our two cases illustrate that severe complications of odontogenic and oropharyngeal infections occur rapidly in patients with diabetes. (5-7) Spread to the deep neck spaces occurred without warning. Because asphyxiation is a known complication of these infections, early endotracheal intubation was performed. We chose antibiotics effective against gram-positive organisms, including anaerobes (ie, ampicillin/sulbactam, clindamycin, and amoxicillin/clavulanic acid). Surgery for debridement and drainage was a necessary part of the management of each case. Fortunately, both patients survived without serious sequelae.

Clinical Anatomy

Understanding the complex anatomy of the neck was critical in evaluating the origin, extent of infection, potential complications, and treatment options. In Patient 1, four potential space infections were considered: the submental, submandibular, sublingual, and lateral pharyngeal spaces. The mylohyoid muscle separates the submandibular and sublingual spaces. The root of the second and third mandibular molar teeth lies below the mylohyoid muscle. In Patient 1, we were presented with a patient manifesting right mandibular tenderness, neck swelling, and a draining cutaneous lesion. At surgical exploration, a cervical necrotizing fasciitis was observed extending to the muscular and fascial attachments of the hyoid bone. As was clinically observed, infection in these teeth usually localizes to the submandibular space. In contrast, the root of the mandibular incisors lies above the mylohyoid muscle, and infection of the incisors tends to spread to the sublingual space. The surgical approach to drainage of these infections differs considerably. Submandibular space infections are best drained and debrided via an extraoral approach, as was used in Patient 1. Sublingual and submental infections are more ominous, are associated more frequently with airway obstruction, and often require complicated intraoral surgical drainage as well.

The prototype of sublingual and submandibular infections is Ludwig's angina. Ludwig's angina is caused by extension of odontogenic infections in 70 to 80% of cases. (3,8) Our cases did not meet strict criteria for this diagnosis: involvement was not bilateral and there was no evidence of involvement of the sublingual space.

The lateral pharyngeal space is an inverted cone extending from the sphenoid bone to the hyoid bone. The most common source of infections in this area is extension from surrounding tissue, although infections after penetrating trauma also occur. The lateral pharyngeal space contains the carotid sheath, the cervical sympathetic trunk, and Cranial Nerves IX through XII. Infections of the anterior part of this space, which contains only fatty tissue, are manifested by pain, dysphagia, and trismus. Infections of the posterior compartment of this space, although typically much less symptomatic, are potentially much more catastrophic because the vital structures are involved. Physicians frequently miss infections in this area because fever can be the only symptom at presentation.

Diabetes Mellitus and Deep Space Neck Infections

The relationship between the development of severe deep space infections of the neck and diabetes mellitus is clinically recognized. (7) It is established that lipopolysaccharide secretion by bacteria and infection-mediated upregulation of cytokine synthesis worsen diabetes. (7) In our two cases, the combination of these processes may explain the increase in tissue destruction seen. Whether a more pathogenic subgingival flora was responsible for these cases is unknown.

Microbiology and Therapy

The pathogens recovered in our cases were microaerophilic streptococci, Peptostreptococcus species, Klebsiella pneumoniae, and Lactobacillus species. The bacteria responsible for deep neck infections are usually the normal components of oral flora (anaerobically predominant mixed oral flora). (3) The major anaerobic pathogens in deep space infections of the neck usually include Fusobacterium nucleatum. Bacteroides melaninogenicus, and anaerobic streptococci. (9,10) The anaerobe Eikenella corrodens is frequently isolated in head and neck infections and is becoming increasingly resistant to clindamycin. (11) Gram-negative rods are rarely found in isolates from neck infections, but they may be found in patients with diabetes (Patient 2) or other debilitated or immuno-compromised patients. (1,11,12) Empiric antibiotic therapy must be initiated as soon as possible to optimize penetration of the bone and the blood-brain barrier. [beta]-Lactam and [beta]-lactamase inhibitor combinations are the preferred choice unless the culture data indicate otherwise. (13)

Radiologic Evaluation

Although numerous radiographic techniques are available to evaluate deep neck space infections, CT scanning is invaluable in the initial evaluation of cervical space infections. (14) Both CT scanning and magnetic resonance imaging provide detailed images of the anatomy of the head and neck (Figs. 3 and 4). Computed tomography is more readily available and less expensive and can effectively identify the progression of infection from inflammation to abscess. Infections of the lateral and retropharyngeal spaces that may erode into the carotid sheath will be detected only with computed tomography. If erosion is suspected, angiography is indicated. Diagnostic ultrasound is an inexpensive, noninvasive, and sensitive means of confirming a diagnosis of neck abscess. In one study, it was accurate in detecting pus in 95% of the cases. (12,15) Unfortunately, the detail is inferior to that of CT scanning.

Vascular Complications

Vascular complications of deep space infections of the neck did not arise in these patients. The most common vascular complication is suppurative internal jugular vein thrombosis or Lemierre's syndrome. (16,17) This syndrome usually presents with acute onset of lever, shaking chills, and prostration. Findings on clinical examination are usually subtle and the diagnosis is often missed. The consequences of septic jugular vein thrombosis include bacteremia, septic pulmonary emboli, suppurative subclavian phlebitis, lateral sinus thrombosis, brain abscess, cavernous sinus thrombosis, and other metastatic abscesses. Careful physical examinations and repeated CT scans did not reveal these complications.

Conclusions

These cases represented severe complications of oral infections in patients with diabetes. The first case, cervical necrotizing fasciitis, is an uncommon entity. Mortality rates for this infection are approximately 40%. (18) Clinical experiences reported in the literature (< 100 total cases) emphasize the major role of dentoalvcolar infections as a source for these infections. The second case, spread of infection from the palate to the retropharynx to anterior mediastinitis, illustrates how communications among these potential spaces occur rapidly. Aggressive surgical intervention was necessary in both patients. Results using hyperbaric oxygen are encouraging, but this modality is not available universally. (6) Our review of the literature indicates that diabetes mellitus is a significant comorbidity. The clinical assessment of these infections in patients with diabetes in the ambulatory setting requires careful consideration of potential complications. Knowledge of the involved anatomy can greatly assist clinicians in anticipating potentially fatal complications.

Key Points

* Deep fascial space infections of the head and neck can be life threatening, and spread to the deep neck spaces can occur without warning.

* Early endotracheal intubation should be considered for air protection.

* Understanding the complex anatomy of the neck is critical in evaluating the origin, extent of infection, potential complications, and treatment options.

* The bacteria responsible for deep neck infections are usually the normal components of oral flora.

* The clinical assessment of these infections in ambulatory patients with diabetes requires careful consideration of potential complications.

References

(1.) Blomquist IK, Bayer AS. Life-threatening deep fascial space infections of the head and neck. Infect Dis Clin North Am 1988;2:237-264.

(2.) Goldenberg D, Golz A, Joachims HZ. Retropharyngeal abscess: A clinical review. J Laryngol Otol 1997;111:546-550.

(3.) Chow AW. Life-threatening infections of the head and neck. Clin Infect Dis 1992;14:991-1002.

(4.) Sethi DS, Stanley RE. Deep neck abscesses: Changing trends. J Laryngol Otol 1994;108:138-143.

(5.) Tung-Yiu W, Jehn-Shyun II, Ching-Hung C, Hung-An C. Cervical necrotizing fasciitis of odontogenic origin: A report of 11 cases. J Oral Maxillofac Surg 2000;58:1347-1353.

(6.) Whitesides L, Cotto-Cumba C, Myers RA. Cervical necrotizing fasciitis of odontogenic origin: A case report and review of 12 cases. J Oral Maxillofac Surg 2000;58:144-151.

(7.) Li X. Kolltveit KM, Tronstad L, Olsen I. Systemic diseases caused by oral infection. Clin Microbiol Rev 2000;13:547-558.

(8.) Hall SF. Ludwig's-like angina (pseudo-angina Ludovici). J Otolaryngol 1984;13:321-324.

(9.) Baker AS, Montgomery WW. Oropharyngeal space infections. Curr Clin Top Infect Dis 1987;8:227-265.

(10.) Sakaguchi M, Sato S, Ishiyama T, Katsuno S, Taguchi K. Characterization and management of deep neck infections. Int J Oral Maxillofac Surg 1997;26:131-134.

(11.) Marra S, Hotaling AJ. Deep neck infections. Am J Otolarygol 1996; 17:287-298.

(12.) el-Sayed Y, al Dousary S. Deep-neck space abscesses. J Otolaryngol 1996;25:227-233.

(13.) Plaza Mayor G, Martinez-San Millan J, Martinez-Vidal A. Is conservative treatment of deep neck space infections appropriate? Head Neck 2001;23:126-133.

(14.) Weber AL, Siciliano A. CT and MR imaging evaluation of neck infections with clinical correlations. Radiol Clin North Am 2000;38:941-968.

(15.) Brinkmann G, Brix F, Beigel A. Ultrasound, computerized and nuclear magnetic resonance tomography of soft tissue processes of the head and neck [in German]. Rontgenblatter 1990;43:58-64.

(16.) Lee BK, Lopez F, Genovese M, Loutit JS. Lemierre's syndrome. South Med J 1997;90:640-643.

(17.) Perez de Liano LA, Soilan del Cerro JL, Coira Nieto A. Lemierre's syndrome: A non-forgotten disease [in Spanish]. Arch Bronconeumol 1997;33:107-108 (letter).

(18.) Valko PC, Barrett SM, Campbell JP. Odontogenic cervical necrotizing fasciitis. Ann Emerg Med 1990;19:568-571.

From the Division of Infectious Disease, Case Western Reserve University, University Hospitals of Cleveland, and the Sections of Otolaryngology and Infectious Diseases, Louis Stokes Veterans Affairs Medical Center, Cleveland, OH.

Supported by the Merit Review Program of the Department of Veterans Affairs (Dr. Bonomo).

Reprint requests to Robert A. Bonomo, MD, Infectious Diseases Section, Louis Stokes Veterans Affairs Medical Center, 10701 East Blvd., Cleveland, OH 44106. Email: [e-mail]

Accepted April 24, 2002.