2. EVIDENCE-BASED MANAGMENT
“Criton, in Thasus, while still on foot, and going
about, was seized with a violent pain in the
great toe; he took to bed the same day, had
rigors and nausea, recovered his heat slightly,
at night was delirious. On the second, swelling
of the whole foot, and about the ankle
erythema, with distension and small bullae
(phlyctaenae); acute fever; he became
furiously deranged; alvine discharges bilious,
unmixed, and rather frequent. He died on the
second day from the commencement.”
HIPPOCRATES, 4th Century B.C.
VISUAL I.D.
SSTI OVERVIEW
GOALS
INTRO
HISTORY
TITLE
NOT GOALS
ANATOMY
3. EVIDENCE-BASED MANAGMENT
“Thou art a boil, a plague-sore,
an embossed carbuncle, in my
corrupted blood.”
-King Lear, Act II, Scene IV
VISUAL I.D.
SSTI OVERVIEW
GOALS
INTRO
HISTORY
TITLE
NOT GOALS
ANATOMY
4. EVIDENCE-BASED MANAGMENT
“Most recommendations for the
diagnosis and treatment of skin and
soft-tissue infections are based on
tradition, consensus, or (too often)
medical mythology. The literature on
this subject is crippled by a paucity of
randomized, controlled trials.”
FAQs
Slaven EM, DeBlieux PM. Skin and soft tissue infections: The common,
the rare and the deadly. EM Practice 2001;3(1):1-22
VISUAL I.D.
SSTI OVERVIEW
GOALS
INTRO
HISTORY
TITLE
NOT GOALS
ANATOMY
5. EVIDENCE-BASED MANAGMENT
CELLULITIS
1. Review skin anatomy
2. Describe types of SSTIs
3. Current best evidence
• Diagnosis
• Management
4. Highlight CDC and IDSA
recommendations
FAQs
VISUAL I.D.
SSTI OVERVIEW
GOALS
INTRO
HISTORY
NOT GOALS
ANATOMY
11. EVIDENCE-BASED MANAGMENT
Infectious epidermal eruptions of flaccid
pustules, which rupture to form a thick
honey-colored to brown crust.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
13. EVIDENCE-BASED MANAGMENT
Inflammation of the hair follicle that appears
clinically as an eruption of pustules and/or
papules centered upon hair follicles.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
15. EVIDENCE-BASED MANAGMENT
An ulcerative pyoderma of the skin
often referred to as a deeper form of
impetigo.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
17. EVIDENCE-BASED MANAGMENT
Acute beta-hemolytic group A streptococcal
infection of the skin involving the superficial
dermal lymphatics that causes marked swelling.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
19. EVIDENCE-BASED MANAGMENT
Deep subcutaneous infection of the skin
that results in a localized area of
erythema and inflammation.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
20. EVIDENCE-BASED MANAGMENT
All that is red is not cellulitis!
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
22. EVIDENCE-BASED MANAGMENT
Localized infection with accumulation of
PMN leukocytes with tissue necrosis involving
the dermis and subcutaneous tissue.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
24. EVIDENCE-BASED MANAGMENT
An infection of the deeper layers of skin and
subcutaneous tissues which spreads along
fascial planes. Type I = polymicrobial infection,
Type II = monomicrobial infection.
CULTURE
CELLULITIS: Q1
RISK FX
vs ERYSIPELAS
CELLULITIS
FAQs
VISUAL I.D.
SSTI OVERVIEW
ANATOMY
38. EVIDENCE-BASED MANAGMENT
• Often “soft” findings on XR, US, CT
• No studies on imaging cellulitis
• XR reasonable for foreign body
ANTIBIOTICS
Struk DW. Munk PL. Lee MJ. Ho SG. Worsley DF. Imaging of soft tissue infections.
Radiologic Clinics of North America. 2001;39(2):277-303
CELLULITIS: Q5
MRSA
CELLULITIS: Q4b
ORGANISMS
CELLULITIS: Q4a
IMAGING
CELLULITIS: Q3
BLOOD Cx
46. EVIDENCE-BASED MANAGMENT
• CA-MRSA is most common cause
of “purulent” cellulitis in the ED
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
CELLULITIS: Q5
MRSA
CELLULITIS: Q4b
ORGANISMS
47. EVIDENCE-BASED MANAGMENT
• Assume CA-MRSA causes “non-
purulent” cellulitis sometimes
• But... Probably not as common
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
CELLULITIS: Q5
MRSA
CELLULITIS: Q4b
ORGANISMS
50. EVIDENCE-BASED MANAGMENT
Moran GJ, Krishnadasan A, et al. Methicillin-resistant S. aureus infections among
patients in the emergency department. N Engl J Med. 2006;355(7):666-74
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
CELLULITIS: Q5
MRSA
51. EVIDENCE-BASED MANAGMENT
Frazee BW, Lynn J, et al. High prevalence of methicillin-resistant Staphylococcus
aureus in emergency department skin and soft tissue infections. Ann Emerg Med.
2005;45(3):311-20
1. MRSA should be covered (first
line) only in certain high-risk
populations
Homeless
Jail
IVDU
Recent hospitalization / Abx
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
CELLULITIS: Q5
MRSA
52. EVIDENCE-BASED MANAGMENT
Phillips S, et al. Analysis of empiric antimicrobial strategies for cellulitis in the era of
methicillin-resistant Staphylococcus aureus. Ann Pharmacother. 2007 Jan;41(1):13-20
2. The safest, most cost-effective
strategy depends on local
prevalence
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
CELLULITIS: Q5
MRSA
54. EVIDENCE-BASED MANAGMENT
ABSCESS: Q3
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
55. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Outpt 1st Line (A-I):
• Semisynthetic PCNs - dicloxacillin
• 1st / 2nd gen cephalosporin - cephalexin
Outpt 2nd Line (or PCN allergy) (A-I):
• Macrolide – erythro/azithromycin
• Clindamycin
• Fouroquinolones – levofloxacin
MRSA coverage only if suspected
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
56. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Outpt 1st Line (A-I):
• Semisynthetic PCNs - dicloxacillin
• 1st / 2nd gen cephalosporin - cephalexin
Outpt 2nd Line (or PCN allergy) (A-I):
• Macrolide – erythro/azithromycin
• Clindamycin
• Fouroquinolones – levofloxacin
MRSA coverage only if suspected
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
57. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Inpt 1st Line (A-I):
• Pen G, nafcillin, oxacillin, cefazolin
Inpt (PCN allergy) (A-I):
• Clindamycin, vancomycin, tigecycline,
linezolid
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
IDSA RECS
CDC RECS
ANTIBIOTICS
60. EVIDENCE-BASED MANAGMENT
ANESTHESIA
Macfie J, Harvey J. The treatment of acute superficial abscesses: a prospective
clinical trial. Br J Surg 1977; 64:264–6.
Tonkin DM, Murphy E, et al. Perianal abscess: a pilot study comparing packing with
nonpacking of the abscess cavity. Dis Colon Rectum. 2004 Sep;47(9):1510-4.
Llera JL, Levy RC. Treatment of cutaneous abscess: a double-blind clinical study. Ann
Emerg Med 1985; 14:15–9.
• I&D alone is effective in most cases
ABSCESS: Q4
IMAGING
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
61. EVIDENCE-BASED MANAGMENT
Macfie J, Harvey J. The treatment of acute superficial abscesses: a prospective
clinical trial. Br J Surg 1977; 64:264–6.
• I&D alone is effective in most cases
• 1⁰ closure increases recurrence
ANESTHESIA
ABSCESS: Q4
IMAGING
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
62. EVIDENCE-BASED MANAGMENT
Abraham N, Doudle M, Carson P. Open versus closed surgical treatment of
abscesses: a controlled clinical trial. Aust N Z J Surg. 1997 Apr;67(4):173-6.
• Some studies of closure after I&D
• These do not apply to us!!
ANESTHESIA
ABSCESS: Q4
IMAGING
ABSCESS: Q3
PACKING
ABSCESS: Q2
ABSCESS I&D
ABSCESS: Q1
ABSCESS
66. EVIDENCE-BASED MANAGMENT
ANTIBIOTICS
Ultrasound is probably useful in SSTI:
• Squire et al (2005) – Bedside US 86%
sensitive and 70% specific for abscess
• Tayal et al (2006) – Bedside US changed
management in about half
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
ABSCESS: Q4
IMAGING
ABSCESS: Q3
PACKING
67. EVIDENCE-BASED MANAGMENT
Plain film should be
ordered for FB
CT if concern that
cavity tracks deep
Struk DW. Munk PL. Lee MJ. Ho SG. Worsley DF. Imaging of soft tissue infections.
Radiologic Clinics of North America. 2001;39(2):277-303.
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
ABSCESS: Q4
IMAGING
ABSCESS: Q3
PACKING
72. EVIDENCE-BASED MANAGMENT
NEC FASC: Q1
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
Davis SL, Perri MB, et al. Epidemiology and outcomes of community-associated
methicillin-resistant Staphylococcus aureus infection. J Clin Microbiol. 2007;45(6):1705
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
73. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
Kazakova SV, Hageman JC, et al. A Clone of Methicillin-Resistant Staphylococcus
aureus among Professional Football Players. N Engl J Med 2005;352:468.
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
74. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
• Inducible clindamycin resistance
Deresinski S. Methicillin-Resistant Staphylococcus aureus: An Evolutionary,
Epidemiologic, and Therapeutic Odyssey. Clinical Infectious Diseases 2005;40:562–573
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
75. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
• Inducible clindamycin resistance
• Recurrent in 10-23%
Daum RS. Clinical practice. Skin and soft-tissue infections caused by methicillin-
resistant Staphylococcus aureus. N Engl J Med. 2007;357(4):380-90
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
76. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
• Inducible clindamycin resistance
• Recurrent in 10-23%
• More easily spread
Zafar U, Johnson LB, et al. Prevalence of nasal colonization among patients with
community-associated methicillin-resistant Staphylococcus aureus infection and their
household contacts. Infect Control Hosp Epidemiol. 2007;28(8):966-9
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
77. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
• Inducible clindamycin resistance
• Recurrent in 10-23%
• More easily spread
• Necrotizing more often than MSSA
Wang JL, et al. Comparison of both clinical features and mortality risk associated
with bacteremia due to community-acquired methicillin-resistant Staphylococcus
aureus and methicillin-susceptible S. aureus. Clin Infect Dis. 2008;46(6):799-806
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
78. EVIDENCE-BASED MANAGMENT
MRSA carries additional virulence
genes (Panton-Valentine leukocidin)
• USA 300 – not from hospitals
• Inducible clindamycin resistance
• Recurrent in 10-23%
• More easily spread
• Necrotizing more often than MSSA
• Outcomes are worse
Davis SL, Perri MB, et al. Epidemiology and outcomes of community-associated
methicillin-resistant Staphylococcus aureus infection. J Clin Microbiol. 2007;45(6):1705
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
79. EVIDENCE-BASED MANAGMENT
SSTI incidence increasing since MRSA
emergence
Pallin DJ, et al. Increased US emergency department visits for skin and soft tissue infections,
and changes in antibiotic choices, during the emergence of community-associated
methicillin-resistant Staphylococcus aureus. Ann Emerg Med. 2008 Mar;51(3):291-8
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
80. EVIDENCE-BASED MANAGMENT
Many studies looking at prevalence
Moran GJ, et al. Methicillin-resistant S. aureus infections among patients in the
emergency department. N Engl J Med. 2006;355(7):666-74
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
81. EVIDENCE-BASED MANAGMENT
Risk factors for MRSA include:
Frazee BW, et al. High prevalence of MRSA in emergency department skin and
soft tissue infections. Ann Emerg Med. 2005;45(3):311-20
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
ABSCESS: Q5
ANESTHESIA
83. EVIDENCE-BASED MANAGMENT
LRINEC
Burn et al 1957: PCN effective after I&D
despite very high rates of resistance
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
84. EVIDENCE-BASED MANAGMENT
Burn et al 1957: PCN effective after I&D
despite very high rates of resistance
Many studies: I&D alone is effective
Macfie J, Harvey J. The treatment of acute superficial abscesses: a prospective
clinical trial. Br J Surg 1977; 64:264–6
Stewart MP, Laing MR, Krukowski ZH. Treatment of acute abscesses by incision,
curettage and primary suture without antibiotics: a controlled clinical trial. Br J
Surg. 1985 Jan;72(1):66-7
Llera JL, Levy RC. Treatment of cutaneous abscess: a double-blind clinical study.
Ann Emerg Med 1985; 14:15–9
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
85. EVIDENCE-BASED MANAGMENT
I&D vs I&D + cephalexin equivalent (10% failure)
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
86. EVIDENCE-BASED MANAGMENT
“Incision and drainage without adjunctive antibiotic
therapy was effective management of CA-MRSA skin
and soft tissue abscesses with a diameter of <5 cm in
immunocompetent children.”
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
MRSA
88. EVIDENCE-BASED MANAGMENT
NEC FASC: Q2
http://www.cdc.gov/mrsa/mrsa_initiative/skin_infection/mrsa_algorithm.html
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
ABSCESS: Q6
89. EVIDENCE-BASED MANAGMENT
SUMMARY
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
• I&D (A-I) packing not necessary
• Culture not warranted (E-III)
• Antibiotics not warranted in simple
abscess (E-III)
• Eradication should be attempted in
outbreaks (B-III)
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
90. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Outpt 1st line (A-I):
• Tetracyclines, TMP-SMX, linezolid, + other
Outpt 2nd line (kids, sulfa allergy) (A-I):
• Clindamycin
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
91. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Inpt 1st line (A-I):
• vancomycin, daptomycin, linezolid
Inpt 2nd line:
• TMP-SMX, rifampin
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
ANTIBIOTICS
93. EVIDENCE-BASED MANAGMENT
Type I: Polymicrobial
Type II: Monomicrobial
GAS accounts for 25-50%
MRSA is a cause
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
94. EVIDENCE-BASED MANAGMENT
Mortality – 34%
Antibiotics:
• Prevent overwhelming sepsis
• No role in cure
Green RJ, Dafoe DC, Raffin TA: Necrotizing fasciitis. Chest 1996; 110:219–229
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
IDSA
CDC
96. EVIDENCE-BASED MANAGMENT
Anaya DA, Dellinger EP. Necrotizing soft-tissue infection: diagnosis
and management. Clin Inf Dis. 2007; 44:705-10
• Pain out of proportion
• Violaceous bullae
• Cutaneous
hemorrhage
• Skin sloughing
• Skin anesthesia
• Rapid progression
• Gas in the tissue
• Skip lesions
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
NEC FASC
97. EVIDENCE-BASED MANAGMENT
Retrospective, observational
• Derivation cohort (89/314)
• Validation cohort (56/140)
Wong CH, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis)
score: a tool for distinguishing necrotizing fasciitis from other soft tissue
infections. Crit Care Med. 2004;32(7):1535-41
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
98. EVIDENCE-BASED MANAGMENT
Wong CH, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis)
score: a tool for distinguishing necrotizing fasciitis from other soft tissue
infections. Crit Care Med. 2004;32(7):1535-41
≤2.5
>2.5
≤180
>180
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
99. EVIDENCE-BASED MANAGMENT
Wong CH, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis)
score: a tool for distinguishing necrotizing fasciitis from other soft tissue
infections. Crit Care Med. 2004;32(7):1535-41
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
100. EVIDENCE-BASED MANAGMENT
145 cases of NF
• 2 had score < 5
• 2 had score = 5
Using cutoff of < 6
• PPV = 92%
• NPV = 96%
Wong CH, et al. The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis)
score: a tool for distinguishing necrotizing fasciitis from other soft tissue
infections. Crit Care Med. 2004;32(7):1535-41
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
NEC FASC: Q1
102. EVIDENCE-BASED MANAGMENT
Stevens DL, Bisno AL, et al. Infectious Diseases Society of America. Practice guidelines
for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis.
2005;41(10):1373-406
Surgery is the definitive tx (A-III)
Necrotizing fasciitis from GAS:
• clindamycin and penicillin (A-II)
Community-acquired mixed infections:
• ampicillin-sulbactam plus clindamycin
plus ciprofloxacin (A-III)
THE END
SUMMARY
NEC FASC: Q2
LRINEC
NEC FASC
103. EVIDENCE-BASED MANAGMENT
1. No cultures in uncomplicated
cellulitis
2. Don’t automatically cover MRSA
THE END
SUMMARY
NEC FASC: Q2
LRINEC
104. EVIDENCE-BASED MANAGMENT
1. I&D all abscesses
2. Wick, don’t pack
3. Assume MRSA
4. Antibiotics if >5cm
TMP-SMX or doxycycline +
THE END
SUMMARY
NEC FASC: Q2
LRINEC
So I’ll start off by lowering the bar a little bit. I’m not super happy with this lecture. In retrospect, it is too broad of a topic to cover in one lecture. It could really be divided into 3 lectures. One on cellulitis, one on abscess and one on necrotizing infections.
Let’s start with some history. What was Criton suffering from? Pain out of proportion to exam. Starts as a local process. Quickly causes systemic illness. Swelling. Erythema. Bullae. AMS. Death. Sounds like Hippocrates is describing a rapidly progressive skin and soft tissue infection like necrotizing fasciitis.
Skin and Soft Tissue Infections (SSTIs) are some of the earliest and most well-described bacterial infections in the historical medical literature. The function of antibiotic substances was first described by Pasteur in 1877 and despite millennia of trying to treat SSTIs and 135 years of antibiotic research, we still have difficulty diagnosing and managing these infections.
This is the problem:
First we’re going to review skin anatomy. Second, were going to describe the various types of SSTIs. We’re going to review the current best evidence for diagnosis and management of SSTIs by trying to answer some of the common questions we kick around regarding SSTIs. And we’re going to highlight the current CDC and IDSA recommendations.
I should also mention a couple of things that we’re NOT going to focus on.
OK, just a brief review of skin anatomy. The most superficial layer is the keratinized epidermis. Next we have the dermis which contains the majority of the glands and functional structures of the skin. Below this is the subcutaneous fat followed by deep structures such as fascia, muscle, cartilage and bone.
SSTIs can be cause by bacterial, fungal, viral and parasitic organisms. They are typically classified based on the pathogen as well as the depth of involvement. You will hear them referred to as SSTI, cSSSI, ABSSSI, etc. etc.
Just a reminder. Bewware the red herring. All that is red is not cellulitis. It seems like more and more when someone presents with any lower extremity redness, we order an US to r/o DVT, then if the US is negative, our default is to call it cellulitis and treat with antibiotics. This is actually venous stasis dermatitis. This person’s legs always look that way. It might be warm, but is usually not painful. It is common to see this unilaterally especially after vein harvesting for CABG.
Necfasc can present with impressive skin findings but the problem is that sometimes it presents with little to no skin changes, like this.
Cellulitis and erisypelas are not the same disease process. It is important to make the distinction between these two diseases because it will affect the way that we treat the infection.
There are only a handful of studies looking at culturing cellulitis. There are two ways to try to cx – needle aspiration or biopsy – and the studies vary widely in success rates. This is the largest study of needle aspiration I could find and resulted in isolation of potential pathogen in only 10%. Punch biopsy is a little better at 25-40%.
There are only a handful of studies looking at culturing cellulitis. There are two ways to try to cx – needle aspiration or biopsy – and the studies vary widely in success rates. This is the largest study of needle aspiration I could find and resulted in isolation of potential pathogen in only 10%. Punch biopsy is a little better at 25-40%.
Punch biopsy is a little better at 25-40% but you have to actually punch out a section of skin and get someone in the lab to either culture the specimen or do immunoflourescent staining to determine the pathogen in less than half of the cases.
First, let’s agree that in the afebrile and “not sick” category of patients, blood cultures are rarely useful – except to meet quality measures.
The largest study included in the meta-analysis was by Perl et al – out of 553 pts, 2% had positive blood cx. 82% of those were gram+. So in only 2/553 pts, was an organism isolated that could have influenced management.
They do comment that there is not enough data to know whether it may be more useful in immunocompromisedpts that may be more at risk for bacteremia.
Imaging of the diabetic foot or chronic wounds in order to evaluate for osteomyelitis is a different story.
The best review article I can find on erysipelas suggests that strep species are responsible for almost all erysipelas. Although this article was published before the age of MRSA, they note that all studies where culture of erysipelas was attempted, found strep as the primary pathogen. In addition, when reviewing all studies on treatment of erysipelas we see that many of these included macrolides (which have relatively poor action against staph) and still resulted in high cure rates. So most current recommendations are that when we see erysipelas, we treat for strep. This study from 1989 found that 96% of cases of erysipelas were strep.
Answering the question about the causal organisms for cellulitis is a more difficult question.
The few older studies have found strep as the predominant cause when cultures can be obtained. I’ve even told some of you this in the ED.
More recently, a systematic review of all studies looking at cellulitis in intact skin found that half of the isolates are staph and only about a quarter are strep. This review included the older studies but also some smaller, newer studies and may suggest that the epidemiology is changing. They were not able to tell us how much of that staph is MRSA.
More recently, a systematic review of all studies looking at cellulitis in intact skin found that half of the isolates are staph and only about a quarter are strep. This review included the older studies but also some smaller, newer studies and may suggest that the epidemiology is changing. They were not able to tell us how much of that staph is MRSA.
The problem with answering this question is defining cellulitis.
There is some thought that MRSA possesses certain virulence factors that increase the likelihood of abscess formation, therefore without abscess, MRSA is a less likely cause of the infection.
The best information I found was actually a recent pharmacoeconomic analysis of the question. In their study they present this diagram. What it shows is that initial antibiotics for cellulitis should not necessarily be aimed at MRSA unless the probability of the infection being staph are greater than 60% and the probability of MRSA in staph is greater than 60%. Whichis a nice concept in theory, but how could you possibly know that.
Some have argued that MRSA is now so common that the probability of any SSTI being MRSA is greater than 60%. That argument is based on data like this from NEJM. However, again we’re hindered by the ability to culture non-purulent cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
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So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
Well, there are a couple things to know about MRSA. First, it contains the Panton-Valentine Leukocidin. I’m not even going to pretend that I have any idea how this works other than to say that it does seem to allow the bacteria to deystroy cell membranes more easily and therefore create abscesses more easily. This is one of the reasons that MRSA is thought to be less likely in non-purulent cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
Here is the NEJM article from 2006 summarizing a few studies that looked at MRSA prevalence. We see percentages that show a range from a low of 15% to a high of 72%. And it has probably increased since then.
Here is the NEJM article from 2006 summarizing a few studies that looked at MRSA prevalence. We see percentages that show a range from a low of 15% to a high of 72%. And it has probably increased since then.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
In 2007 they studied cure rate after I&D with/without cephalexin. They found almost identical cure rates. Which makes sense since we already believe that many abscesses are caused by MRSA which is resistant to keflex. So this study would suggest that Abx are not needed.
But studies in the age of MRSA are less clear. We do know that physicians are less and less likely to manage abscesses by I&D alone. One of the best studies of simple I&D without antibiotics for the management of cutaneous abscesses was done in 2004 in children. They found that the factor most predictive of cure by I&D alone was the diameter of the total area of inflammation. Many people have tried to make the claim that we should treat “if there is surrounding cellulitis” but unfortunately there are no good studies looking at this.
But studies in the age of MRSA are less clear. We do know that physicians are less and less likely to manage abscesses by I&D alone. One of the best studies of simple I&D without antibiotics for the management of cutaneous abscesses was done in 2004 in children. They found that the factor most predictive of cure by I&D alone was the diameter of the total area of inflammation. Many people have tried to make the claim that we should treat “if there is surrounding cellulitis” but unfortunately there are no good studies looking at this.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
So lets look at some of the recommendations for Abx treatment in cellulitis.
A good review of necfasc in Chest found that even still, mortality is approximately 1/3. That is a staggering number. Antibiotics should be given but their role is really to try to prevent overwhelming sepsis not cure the local disease. These pts must go to the OR and must go fast. Of all of the non-traumatic indications for emergent surgery, this is one of the most time-dependent.
So lets look at some of the recommendations for Abx treatment in cellulitis.
But we still have a very difficult time making this diagnosis. So I’m going to propose that you use the Laboratory Risk Indicator for Necrotizing Infections.
But we still have a very difficult time making this diagnosis. So I’m going to propose that you use the Laboratory Risk Indicator for Necrotizing Infections.
But we still have a very difficult time making this diagnosis. So I’m going to propose that you use the Laboratory Risk Indicator for Necrotizing Infections.
Of the 145 incident cases, 2 had a score less than 5, two had a score of five. So using a cutoff of less than 6, the LRINEC had a PPV 92% and a NPV 96%. Three subsequent validation studies have found the PPV to be much lower 40% (which we’re ok with) but the NPV has been right around 95%. In other words, if the score is <6, you are ok to proceed cautiously with antibiotics but without a fascial biopsy or trip to the OR. If it is over 6, you should be calling a surgeon.
Although it is not on their recommendations, I would also cover with vanc or linezolid. They’re about due for new recommendations and I suspect that will change.
Although it is not on their recommendations, I would also cover with vanc or linezolid. They’re about due for new recommendations and I suspect that will change.
Although it is not on their recommendations, I would also cover with vanc or linezolid. They’re about due for new recommendations and I suspect that will change.
Although it is not on their recommendations, I would also cover with vanc or linezolid. They’re about due for new recommendations and I suspect that will change.