Rosen & Barkin's 5-Minute Emergency Medicine Consult (459 page)

• Skin and soft tissue infections:
  
  • Increasing redness
    
  • Pain
    
  • Warmth
    
  • Swelling
    
  • Fever
    
  • Chills
    
  • Malaise
    
• Sepsis/pneumonia:
  
  • Weakness
    
  • Dyspnea
    
  • Fever
    
  • Rigors
    
  • Productive cough
    
  • Chest pain
    
• Inquire about prior diagnosis of MRSA infections, MRSA exposures, and family members or close contacts with a history of MRSA, as such a patient is at risk for CA-MRSA infection.
  

• Skin and soft tissue infections:
  
  • Abscess: Tender, raised boil with underlying induration and fluctuance
    
  • Cellulitis: Warm erythema possibly with lymphangitic streaking
    
• Sepsis:
  
  • Vital sign abnormalities including tachycardia and hypotension, respiratory failure, mental status changes, petechiae, systemic signs of toxicity
    
• Pneumonia:
  
  • Tachypnea, crackles, retractions, hypoxia
    
  • Alveolar opacities on chest radiographs
    

MRSA is the leading cause of skin and soft tissue infections among children presenting to the emergency department.

• Abscess:
  
  • I&D with packing and prompt follow-up is warranted for abscess
    
  • Microbiology often performed for antibiotic sensitivity given the changing antimicrobial resistance patterns
    
• Sepsis:
  
  • Source identification, including blood culture/urine culture, CXR, is indicated as resuscitation begins
    
• Pneumonia:
  
  • Chest radiographs and continuous vital sign monitoring is indicated
    

• Skin and soft tissue infections:
  
  • Bacterial culture is often warranted to monitor for CA-MRSA resistance patterns
    
• Sepsis and pneumonia:
  
  • Blood, urine, and body fluid cultures. CBC, CMP to assess for organ dysfunction
    

• Bedside US:
  
  • Abscess: Anechoic fluid collection
    
  • Cellulitis: “Cobblestoning” within the soft tissue
    
• CXR:
  
  • Indicated for patients with presumed sepsis, systemic illness, or pneumonia
    

Cultures of skin and soft tissue infections are frequently obtained to monitor microbiology and antimicrobial resistance patterns should a patient fail a course of therapy.

• Other skin and soft tissue infections:
  
  • Pathogens beyond MRSA which cause abscesses and cellulites should be considered (i.e., streptococcus)
    
• Necrotizing fasciitis
  
• Contact dermatitis
  
• Deep vein thrombosis
  
• Spider/insect bite
  
• Drug reaction
  

TREATMENT

• Contact precautions for all providers if MRSA is suspected
  
• IV access and fluid resuscitation if sepsis is suspected
  

Begin resuscitation and administer early empiric antibiotics if pneumonia, fasciitis, or sepsis is suspected:

• Include early coverage with antibiotics effective against MRSA
  

• Skin and soft tissue infections:
  
  • Abscess:
    
    • I&D with packing
      
    • Antibiotics may not be necessary if there is no evidence for deep tissue infection or cellulitis
      
  • Cellulitis:
    
    • Cellulitis caused by CA-MRSA in a healthy, well-appearing patient may be treated with oral antibiotics in the outpatient setting
      
    • Ill appearing patients, patients with underlying medical conditions, and patients failing outpatient therapy require IV antibiotics with coverage against CA-MRSA
      
• Sepsis and pneumonia:
  
  • Early administration of broad-spectrum antibiotics that cover against MRSA should be given promptly if the patient is at risk for CA-MRSA
    

• Bactrim:
  
  • Adults: Bactrim DS 160/800 PO BID
    
  • Children: 10 mg/kg PO BID
    
• Clindamycin:
  
  • Adults: 150–450 mg PO QID
    
  • Children: 5 mg/kg PO/IV TID–QID
    
• Doxycycline:
  
  • Adults: 100 mg PO BID
    
  • Children: 2.2 mg/kg PO BID
    
• Vancomycin:
  
  • Adults: 1 g IV q8–12h
    
  • Children: 15 mg/kg IV q8–12h
    

• Rifampin:
  
  • Should not be used as monotherapy due to inducible resistance
    
  • Adults: 300 mg PO BID
    
  • Children: 10–20 mg/kg/d in 2 div. doses PO for 5 days; not to exceed 600 mg/d
    
• Linezolid:
  
  • Adults: 600 mg PO/IV q12h
    
  • Children: 10 mg/kg PO/IV q8h
    

Avoid the use of tetracyclines in pregnancy

FOLLOW-UP

• Patients with signs/symptoms of bacteremia, progressive infection, or systemic illness should be admitted:
  
  • Fever, chills, lymphangitic streaking
    
• Patients with underlying comorbid diseases such as diabetes or immunodeficiency should be admitted
  
• Individuals who have failed a course of outpatient therapy should be admitted and given IV antibiotics effective against MRSA
  

Healthy, well-appearing patients with simple skin and soft tissue infections may be followed in the outpatient setting.

MRSA infection refractory to multiple medications may require infectious disease consultation.

• All skin and soft tissue infections should be re-evaluated within 24–48 hr to monitor for clinical improvement.
  
• Individuals failing outpatient therapy require hospital admission and IV antibiotics.
  

• CA-MRSA is the most common cause of skin and soft tissue infections seen in the ED.
  
• CA-MRSA is a rare but serious cause of rapidly progressive pneumonia and sepsis.
  
• Antibiotic resistance patterns are dynamic and vary widely across geographic boundaries.
  
• Be cautious with long-term use of tetracyclines in children.
  

• Frazee BW, Lynn J, Charlebois ED, et al. High prevalence of methicillin-resistant
  Staphylococcus aureus
  in emergency department skin and soft tissue infections.
  Ann Emerg Med
  . 2005;45:311–320.
  
• Klevens RM, Morrison MA, Nadle J, et al. Invasive methicillin-resistant
  Staphylococcus aureus
  infections in the United States.
  JAMA
  . 2007;298:1763–1771.
  
• Moran GJ, Krishnadasan A, Gorwitz RJ, et al. Methicillin-resistant
  S. aureus
  infections among patients in the emergency department.
  N Engl J Med.
  2006;355:666–674.
  
• Odell CA. Community-associated methicillin-resistant
  Staphylococcus aureus
  (CA-MRSA) skin infections.
  Curr Opin Pediatr
  . 2010;22:273–277.
  
• Wallin TR, Hern HG, Frazee BW. Community-associated methicillin-resistant
  Staphylococcus aureus
  .
  Emerg Med Clin North Am
  . 2008;26:431–455.
  

See Also (Topic, Algorithm, Electronic Media Element)

• Abscess
  
• Cellulitis
  
• Pneumonia
  
• Sepsis
  

CODES

041.12 Methicillin resistant Staphylococcus aureus in conditions classified elsewhere and of unspecified site

BASICS