Deep Neck Space Infections Organism-Specific Therapy

Deep neck space infections, including parapharyngeal abscess, peritonsillar abscess, and retropharyngeal abscess, are often of ontogenic, sinus, or upper aerodigestive tract origin. The bacteriology tends to be polymicrobial, involving both aerobic and anaerobic bacteria from the primary source. If not diagnosed and treated promptly, these infections may be life-threatening, as a result of airway compromise and the spread of infection to neighboring neck spaces. Initial empiric antimicrobial therapy should include broad coverage for aerobic bacteria, including gram-positive organisms such as Staphylococcus aureus and Streptococcus pyogenes, and gram-negative bacteria such as Haemophilus influenzae and Klebsiella pneumoniae. Anaerobic bacteria, including gram-positive organisms such as Peptostreptococcus species, and gram-negative bacteria such as Prevotela species, should be broadly covered as well. Broad coverage should continue until culture results are obtained to help direct treatment. ^{[1, 2, 3, 4, 5, 6, 7, 8]} Specific therapy upon obtaining organism and susceptibility information is detailed below.

Streptococcus pyogenes, Streptococcus viridans, Staphylococcus aureus

See the list below:

• Ampicillin-sulbactam (3 g IV q6h)  or
• Ceftriaxone (2g IV q24h) plus metronidazole (500 mg IV q8h) or
• Clindamycin (600 mg IV q8h)  plus levofloxacin (750 mg IV q24h)

Oral anaerobes (eg, Prevotella, Porphyromonas, Fusobacterium, Bacteroides, and Peptostreptococcus species)

See the list below:

• Clindamycin 600 mg IV q8h  or
• Penicillin G (2-4 million U IV q4-6h)  plus   metronidazole (500 mg IV q8h)

Methicillin-susceptible Staphylococcus aureus (MSSA)

See the list below:

• Clindamycin 600 mg IV q8h  or
• Nafcillin 1.5 g IV q4h  or
• Ceftriaxone 1 g IV q12h  or
• Ampicillin-sulbactam 3 g IV q6h

Methicillin-resistant Staphylococcus aureus (MRSA)

See the list below:

• Vancomycin 1000 mg (15 mg/kg) IV q12h  or
• Linezolid 600 mg IV q12h  or
• Daptomycin 4-6 mg/kg IV q24h or
• Clindamycin 600 mg IV q8hr

Haemophilus influenzae

See the list below:

• Ceftriaxone 1 g IV q12h  or
• Ampicillin-sulbactam 3 g IV q6h

Pseudomonas aeruginosa

See the list below:

• Piperacillin-tazobactam 4.5 g IV q6h or 3.375 g IV q4h, usually over 30 min or
• Cefepime 2 g q8h or
• Ciprofloxacin 400 mg IV q12h or
• Aztreonam 2 g q8h or
• Meropenem 1 g q8h

Duration of therapy

Parenteral therapy is indicated until the patient is afebrile, with a clear clinical improvement in symptoms for 48h. Afterwards, the patient may transition to oral antibiotics and complete a 2- to 3-week course of treatment. Longer courses may be required when complications are present.

Special considerations

Airway protection is the first priority with deep neck space infections; this may involve oxygenation with pressure support, IV steroids, intubation (nasal or oral), tracheostomy, or cricothyroidotomy (for emergent situations). ^[4]

If, after 48-72 hours, no clinical improvement is observed in association with conservative treatment with IV hydration and antibiotics, aspiration or surgical incision and drainage should be considered.

Anteroposterior and lateral neck radiographs may be useful for evaluating airway patency and as a screening tool for children who are suspected of having a deep neck or retropharyngeal infection.

Computed tomography (CT) scanning with contrast is the imaging modality of choice for deep neck space infections and is useful for evaluating whether a mass has organized into a drainable collection.

Spread of infection into the mediastinum may result in fever, tachycardia, and chest pain. The clinician should have a low threshold for obtaining surgical consultation when these ominous signs are present.

Urgent surgical consultation should be obtained for rapidly progressive cutaneous erythema, underlying crepitus, and findings of gas bubbles on CT imaging, as these findings are concerning for necrotizing fasciitis.

Broad-spectrum empiric antimicrobial therapy should be narrowed once results from culture and susceptibility data are obtained.