Rosen & Barkin's 5-Minute Emergency Medicine Consult (680 page)

• Pain:
  
  • Most common initial symptom of NF:
    
    • Occurs in 85% of cases
      
  • Out of proportion to physical findings
    
  • Often abrupt in onset and severe
    
  • Often requires palliative IV narcotics
    
  • Usually involves an extremity
    
  • May mimic peritonitis, pelvic inflammatory disease, pneumonia, acute MI, or pericarditis
    

• Fever
  most common sign:
  
  • Can present with hypothermia, especially if patient is in shock
    
• Altered mental status
  present in 55% of cases
  
• Soft tissue infection
  (erythema and swelling) present in 80%:
  
  • Indistinct borders, blisters, bullae
    
  • No lymphangitis or lymphadenopathy
    
• Influenza-like syndrome in 20%:
  
  • Fever
    
  • Chills
    
  • Myalgias
    
  • Nausea, vomiting
    
  • Diarrhea
    
• Shock:
  
  • Present at admission or within 4–8 hr in
    all
    patients
    
  • Frequently persists despite fluids, antibiotics, and vasopressors
    
• Renal failure:
  
  • Precedes onset of shock in many cases
    
  • Dialysis often necessary
    
  • Kidney function returns to normal within 4–6 wk in survivors.
    
• ARDS:
  
  • Occurs in 55% of patients
    

• Suspect NF when pain is out of proportion to exam.
  
• Obtain plain films to search for presence of air in soft tissues.
  
• Blood cultures should be obtained.
  

• CBC with differential:
  
  • Mild leukocytosis with left shift initially
    
• Electrolytes, BUN, and creatinine
  
• Calcium level:
  
  • Hypocalcemia in association with fat necrosis from NF
    
• Urinalysis:
  
  • Hemoglobinuria if renal involvement
    
• Serum creatine phosphokinase:
  
  • An elevated or rising level correlates with NF or myositis.
    
• Aerobic and anaerobic blood cultures
  
• Wound cultures
  
• PT/PTT/INR/DIC panel
  

• Plain films:
  
  • Gas in soft tissues in 25–75% of cases of NF, but not as frequently associated with group A β-hemolytic streptococcal infection
    
  • More common in mixed anaerobic infections
    
• CT scan:
  
  • Asymmetric thickening of deep fascia
    
  • Gas
    
• MRI:
  
  • High signal intensity of the fascia in T2-weighted images associated with NF
    

Aspiration of involved areas with Gram stain and culture may be useful

• Sepsis
  
• Cellulitis
  
• Erysipelas
  
• NF/myositis secondary to infection by another pathogen
  

TREATMENT

Stabilize as appropriate

• Maintain ABCs.
  
• Treat shock with fluids and vasopressors as needed:
  
  • Hypotension is often intractable, and up to 10–20 L/day may be required.
    
• Intubation and mechanical ventilation for:
  
  • ARDS
    
  • Severe shock
    
  • Ventilatory failure
    

• Broad-spectrum antibiotics immediately after cultures until the presence of GAS has been confirmed:
  
  • Clindamycin is a potent suppressor of GAS bacterial toxin synthesis and inhibits M protein synthesis
    
• Early surgical consultation. Most patients will require an operative procedure (e.g., fasciotomy, surgical débridement, exploratory laparotomy, intraocular aspiration, amputation, or hysterectomy):
  
  • Immediate surgery is indicated if there is:
    
    • Extensive necrosis or gas
      
    • Compartment syndrome
      
    • Profound systemic toxicity
      
• Droplet precautions for the 1st 24 hr of antibiotic therapy
  
• Reports of successful use of IV immunoglobulin
  
• Hyperbaric oxygen therapy still controversial
  

• NF due to invasive streptococcal disease (NOTE: In the ED, empiric treatment should be initiated until monomicrobial NF caused by GAS has been confirmed):
  
  • Clindamycin: 900 mg IV (peds: 40 mg/kg/d),
    and
    
  • Penicillin G: 4 million U IV (peds: 250,000 U/d),
    or
    
  • Vancomycin: 15 mg/kg IV (peds: 10 mg/kg q6h) if patient has penicillin allergy
    
• Empiric treatment of NF from all causes (
  Clostridium perfringens
  , GAS, methicillin-resistant
  S. aureus
  [MRSA], mixed anaerobes/aerobes):
  
  • Piperacillin/tazobactam 3.5 g IV
    and
    
  • Clindamycin 900 mg IV
    and
    
  • Vancomycin 1 g IV
    
  • For patients with a penicillin allergy treat with aztreonam 2 g IV, clindamycin 900 mg IV, vancomycin 1 g IV, and metronidazole 500 mg IV
    

FOLLOW-UP

ICU admission required for all patients with suspected invasive streptococcal infection. Mortality from GAS NF ∼20%, but with both NF and STSS, mortality rate increases to 70%.

None

• Hypotension and shock may require large volumes of IV fluids and vasopressors.
  
• Broad-spectrum antibiotics should be administered until the presence of GAS can be confirmed.
  
• Surgical consultation should be obtained for débridement.
  

• Martin JM, Green M. Group A streptococcus.
  Semin Pediatr Infect Dis
  . 2006;17:140–148.
  
• Nuwayhid ZB, Aronoff DM, Mulla ZD. Blunt trauma as a risk factor for group A streptococcal necrotizing fasciitis.
  Ann Epidemiol
  . 2007;17:878–881.
  
• Steer AC, Lamagni T, Curtis N, et al. Invasive group A streptococcal disease: Epidemiology, pathogenesis, and management.
  Drugs
  . 2012;72(9):1213–1227.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Pharyngitis
  
• Toxic Shock Syndrome
  

CODES

• 040.82 Toxic shock syndrome
  
• 041.01 Streptococcus infection in conditions classified elsewhere and of unspecified site, streptococcus, group A
  
• 728.86 Necrotizing fasciitis
  

BASICS

• High-pitched audible wheezing and vibratory harsh sounds mainly on inspiration.
  
• Impedance of air movement through the upper airway.
  
• It implies a laryngotracheal airway obstruction.
  

• Congenital:
  
  • Laryngomalacia
    
  • Laryngeal webs/rings
    
• Vocal cord dysfunction:
  
  • Congenital
    
  • Surgical injury
    
  • Postintubation trauma
    
  • Thyroid malignancy
    
  • Mediastinal mass
    
  • Neural abnormalities (e.g., meningomyelocele, Arnold–Chiari malformation)
    
• Subglottic stenosis:
  
  • Postoperative scarring
    
  • After radiation therapy
    
  • After prolonged endotracheal intubation
    
• Subglottic hemangioma
  
• Infection:
  
  • Bacterial tracheitis
    
  • Epiglottitis
    
  • Viral croup
    
  • Peritonsillar abscess
    
  • Retropharyngeal abscess
    
  • Supraglottitis
    
  • Uvulitis (e.g., Quincke disease)
    
  • Ludwig angina
    
  • Diphtheria
    
  • Tetanus
    
• Extrinsic compression:
  
  • Trauma
    
  • Hematoma
    
  • Vascular anomalies (e.g., rings)
    
• Intraluminal obstruction of the trachea:
  
  • Foreign body
    
  • Tracheomalacia
    
  • Cyst
    
  • Invasive tumors
    
  • Squamous cell
    
  • Lymphomas
    
  • Thyroid masses/carcinomas
    
  • Laryngeal or tracheal papilloma
    
• Angioedema