Skin And Soft Tissue Infection

Front 1

What are risk factors for SSTIs?

Back 1

• Compromised skin integrity
• Impaired venous circulation
• Moisture
• Poor hygiene

Front 2

What are clinical features of MRSA?

Back 2

• Often has purulent discharge/drainage from side
• Spider bite
• Furuncles/carbuncles
• Folliculitis

Front 3

What are risk factors for MRSA?

Back 3

• Hospitalization in the past 24 months
• Outpatient visit in the past 12 months
• Nursing home admission in past 12 months
• Antibiotic exposure in past 12 months
• Chronic medical illness
• Injection drug use
• Close contact with person who has any of the above risk factors.
• Usually > 1 is present

Front 4

what are clinical features of MSSA/hemolytic infections?

Back 4

o Rapidly developing lesion
o Localized pain, tenderness, erythema and inflammation
o Constitutional symptoms
o Possible elevated WBC and lymphadenopathy

Front 5

What are oral tx choices for MSSA/hemolytic infections?

Back 5

-DICLOXACILLIN
-CEPHALEXIN
-CLINDAMYCIN

Front 6

What is dose and duration for clindamycin?

Back 6

-300mg TID 7-10 days

Front 7

What are IV tx choices for MSSA and b-hemolytic strep?

Back 7

NAFCILLIN
CEFAZOLIN
CLINDAMYCIN

Front 8

What kind of infection and what are the clinical features of the infection seen in diabetics?

Back 8

-polymicrobial
o Can range from mild to moderate/severe
o Features can be similar to MSSA/β-hemolytic SSTIs
o Severe infection often includes purulent or serous drainage, foul odor and necrotic tissue

Front 9

What are clinical features of bullous and non bullous impetigo?

Back 9

Non-bullous
o Small papules → vesicles → pustules
o Rupture of pustules results in golden-yellow crust (honey-colored lesions)
o Depigmentation can occur
Bullous
o Superficial vesicles → flaccid bullae with thin yellow fluid → varnish-like crust

Front 10

What is etiology of impetigo?

Back 10

• β-hemolytic streptococci
• MSSA
• MRSA

Front 11

What is tx for non bullous impetigo?

Back 11

• Oral Medications
o Dicloxacillin
o Cephalexin
o TMP/SMX
o Clindamycin
• Topical Medication
o Mupirocin ointment

Front 12

what is tx for bullous impetigo?

Back 12

• IV Medications
o Nafcillin/Oxacillin
o Cefazolin
o Clindamycin
o Vancomycin
o TMP/SMX
-oral meds refer to non bullous

Front 13

What are local care directions for bullous?

Back 13

• Use warm, soapy water to soak and remove crusts
• Do not allow drainage to contaminate common surfaces
• Peeling of scabs can result in permanent scaring

Front 14

What is the etiology of polymicrobial necrotizing fasciitis?

Back 14

• Surgery/Trauma
• PVD/DM
• Decubitus ulcers
• IVDU
• Perianal abscess

Front 15

What is etiology of necrotizing fasciitis?

Back 15

o Most often occurs in previously healthy people
o “Flesh-eating bacteria”
o Streptococcus pyogenes

Front 16

What are clinical features of necrotizing fasciitis?

Back 16

•Erythematous, inflamed, hot and shiny area
•Tender and painful
•Sequential skin color changes occur over several days
•Breakdown of skin and cutaneous gangrene by days 3 to 5
•Fever, elevated WBC

Front 17

What are tx choices for necrotizing fasciitis?

Back 17

•Surgical debridement
•Antimicrobial therapy
oEmpiric coverage for gram-positive, gram-negative and anaerobes
oAmpicillin/sulbactam + clindamycin + ciprofloxacin

Front 18

What are monitoring parameters for necrotizing fasciitis?

Back 18

• Surgical debridement until viable tissue
• WBC, fever (must be afebrile 48 to 72 hours before antimicrobials discontinued)
• Secondary infections

Front 19

What are RF for diabetic foot ulcer?

Back 19

• Foot ulceration
o Peripheral neuropathy
o Vascular insufficiency
• Trauma

Front 20

What is the etiology of monomicrobial diabetic foot ulcers?

Back 20

Gram-positive—seen with acute infections
• staphylococci

Front 21

What is the etiology of polymicrobial foot ulcers?

Back 21

- chronic infections or recent use of antibiotics
o Gram-positive
o Gram-negative-Pseudomonas aeruginosa
o Anaerobes

Front 22

what is mild foot ulcer?

Back 22

• Local infection. Skin and subcutaneous tissue only. No systemic inflammatory response signs (SIRS). If erythematous, < 2 cm around the ulcer.

Front 23

What is moderate foot infection?

Back 23

• Local infection as stated above. Erythema > 2 cm around the ulcer. Involves structures deeper than subcutaneous tissue. No SIRS.

Front 24

What is severe foot infection?

Back 24

• Local infection as described above. SIRS with > 2 of the following present:
• Temp > 38 C or < 36 C
• HR > 90 beats/min
• RR > 20 breaths/min
• WBC > 12K or < 4K

Front 25

What is management of foot ulcers?

Back 25

• Empiric antibiotics
• Definitive antibiotics
• Surgery/resection
• Wound care

Front 26

What does tx for ulcers need to always include?

Back 26

- glycemic control

Front 27

What is tx for outpatient mild to moderate foot ulcer?

Back 27

• Amoxicillin/clavulanate
• Doxycycline, TMP/SMX DS
• Levofloxacin +/- clindamycin

Front 28

What is tx for moderate to severe inpatient foot ulcer?

Back 28

-IV antibiotics• Ampicillin/sulbactam
• Ertapenem
• Vancomycin
• Linezolid
• Piperacillin/tazobactam
• Vanc + cefepime or piperacillin/tazobactam or imipenem/cilistatin

Front 29

What is the duration of tx for foot ulcers?

Back 29

• Mild—1 to 2 weeks
• Moderate to severe—2 to 3 weeks
• Osteomyelitis—up to 4 to 6 weeks or longer

Front 30

What are outpt tx choices for MRSA?

Back 30

TMP/SMX
DOXYCYCLINE
CLINDAMYCIN
LINEZOLID

Front 31

Dose and duration for TMP/SMX

Back 31

2 DS BID to TID 5-10 days

Front 32

Dose and duration for doxycycline

Back 32

100mg BID 5-10 days

Front 33

Dose and duration for linezolid

Back 33

600mg BID 5-10 days

Front 34

What are tx choices for inpatient MRSA?

Back 34

VANCOMYCIN (IV)∗
DAPTOMYCIN IV)∗
CLINDAMYCIN (IV)∗
LINEZOLID (IV OR PO)∗
TELAVANCIN (IV)∗

Front 35

What is the dose and duration for vancomycin?

Back 35

15mg/kg Q8-12H 10 to 14 days

Front 36

dose and duration for daptomycin?

Back 36

4mg/kg/day 10 to 14 days

Front 37

dose and duration for clindamycin?

Back 37

600mg TID 10 to 14 days

Front 38

What is dose for telavancin IV?

Back 38

10mg/kg/day 10 to 14 days
∗ > 14 days

Front 39

What are oral tx for polymicrobial infections?

Back 39

-AMOX/CLAV
-LEVOFLOXACIN + METRONIDAZOLE OR CLINDAMYCIN

Front 40

What are IV tx for polymicrobial infections?

Back 40

-PIP/TAZO +/- VANC
-IMIPENEM +/- VANC
-LEVOFLOXACIN + METRONIDAZOLE OR CLINDAMYCIN +/- VANC

Front 41

When do you consider decolonization tx for MRSA?

Back 41

Considerations
==> Recurrent infections despite adequate therapy
==> Transmission to household

Front 42

What are tx choices for decolonization?

Back 42

==> Mupirocin
• 1 swab in each nare twice daily x 5 to 10 days or first 5 days of each month
==> Chlorhexidine
• Use as body wash 2 to 3 times per week
==> Dilute bleach baths
• 1 tsp bleach per 1 gallon of water or ¼ cup bleach per ¼ tub
• Soak 15 minutes twice weekly

Front 43

Considerations for decolonization of MRSA skin infections

Back 43

Considerations:
==> Recurrent infections despite adequate therapy
==> Transmission to household

Front 44

Medication options for decolonization of MRSA skin infections

Back 44

==> Mupirocin
• 1 swab in each nare twice daily x 5 to 10 days or first 5 days of each month
==> Chlorhexidine
• Use as body wash 2 to 3 times per week
==> Dilute bleach baths
• 1 tsp bleach per 1 gallon of water or ¼ cup bleach per ¼ tub
• Soak 15 minutes twice weekly

Front 45

Clinical features associated w/ osteomyelitis

Back 45

• Fever
• Pain and tenderness
• Inflammation
• Erythema
• Drainage-contiguous route of infection only


•Elevated WBC
o (+) with acute infection
o (+/-) with chronic
•Elevated ESR/CRP
oHematogenous
oVertebral

Front 46

Majority of acute osteomyelitis is caused by what type of organisms?

Back 46

gram positive

Front 47

Majority of chronic osteomyelitis caused by what type of organism?

Back 47

polymicrobial

Front 48

possible routes of infection in osteomyelitis

Back 48

o Hematogenous – spread of bacteria via bloodstream from a distant infection site
o Contiguous – direct infection of the bone from an adjacent source of infection or direct inoculation of the bone (trauma, puncture, surgery)
o Vascular – diabetes mellitus, peripheral vascular disease, generally contiguous

Front 49

Duration of infection in acute and chronic osteomyelitis

Back 49

o Acute – less than 1 week
o Chronic – greater than 1 month

Front 50

Organism associated with hematogenous osteomyelitis

Back 50

• Single organism almost always recovered, Staphylococcus aureus

Front 51

Hematogenous most often seen in what age group?

Back 51

children

Front 52

Vertebral osteomyelitis most often seen in what group?

Back 52

adults greater than 50 years and IVDU

Front 53

Organisms associated with vertebral osteomyelitis

Back 53

Single organism most often involved
o Normal adult-Staphylococcus aureus
o IVDU-Pseudomonas aeruginosa or MRSA
o Known concomitant infection

Front 54

Organisms associated with contiguous osteomyelitis

Back 54

Most commonly involves multiple organisms
o Gram-positive-Staph. aureus, Streptococci, Enterococcus
o Gram-negative
o Anaerobes

Front 55

Is contiguous usually acute or chronic?

Back 55

chronic

Front 56

Predisposing factors for contiguous osteomyelitis in pts with normal vasculature

Back 56

• Surgical reduction and internal fixation of fractures
• Prosthetic devices
• Open fractures
• Chronic soft tissue infections

Front 57

Predisposing factors for contiguous osteomyelitis in pts with abnormal vasculature

Back 57

DM & CAD

Front 58

What area is most commonly involved in contiguous osteomyelitis w/ vascular insufficiency?

Back 58

Small bones of feet
-Inadequate tissue perfusion predisposes pt to infx

Front 59

Pts with contiguous osteomyelitis w/ vascular insufficiency usually present with what signs/sxs

Back 59

ingrown toenail, foot ulcer or cellulitis

Front 60

What is often necessary for tx of contiguous osteomyelitis w/ vascular insufficiency?

Back 60

majority will have recurrence of infection. So, resection of involved area is often necessary

Front 61

Labs involved in diagnosis of osteomyelitis

Back 61

o Microbiologic – cultures of blood and bone
• Identification of causative microorganisms is essential (blood cultures)
• Surgical cultures, needle biopsy (bone cultures)
o WBC – leukocytosis or may be normal
o ESR/CRP – elevated (nonspecific, best for monitoring therapeutic response)

Front 62

Radiographic studies used in osteomyelitis

Back 62

o Conventional X-ray – bone changes do not appear for 10-21 days
o Nuclear imaging - see changes in 2 days
• Technitium99m (triple phase bone scan)
• Indium111 (labeled leukocyte scan)
o CT or MRI - most consider MRI gold standard
o PET

Front 63

Empiric tx of osteomyelitis in a neonate (likely pathogen and antibiotic choice(s))

Back 63

Likely pathogen: S. aureus, group B Strep, E.coli
Abx: Oxacillin/nafcillin or cefazolin or vancomycin
+/- cefotaxime

Front 64

Empiric tx of osteomyelitis in a child <5 yo (likely pathogen and antibiotic choice(s))

Back 64

Likely pathogen: S. aureus, group A Strep, H. flu Abx: Oxacillin/nafcillin or cefazolin or cefuroxime or clindamycin or vancomycin
Alternatives: vancomycin + gentamicin

Front 65

Empiric tx of osteomyelitis in a child >5 yo (likely pathogen and antibiotic choice(s))

Back 65

Likely pathogen: S. aureus
Abx: Oxacillin/nafcillin or cefazolin or clindamycin or vancomycin

Front 66

Empiric tx of osteomyelitis in an adult (likely pathogen and antibiotic choice(s))

Back 66

Likely pathogen: S. aureus
Abx: Vancomycin or Oxacillin/nafcillin or cefazolin or clindamycin

Front 67

Empiric tx of osteomyelitis in an IVDU (likely pathogen and antibiotic choice(s))

Back 67

Likely pathogen: P. aeruginosa, S. aureus (MRSA), other Gram (-) rods
Abx: Anti-pseudomonal B-lactam + vancomycin or
FQs + tobramycin or
ceftazidime + tobramycin

Front 68

Empiric tx of osteomyelitis in a Post-op/post-trauma pt (likely pathogen and antibiotic choice(s))

Back 68

Likely pathogen: Gram (+), Gram (-)
Abx: BL/BLI or 3rd gen Ceph or FQ + Clindamycin all +/- Vancomycin

Front 69

Empiric tx of osteomyelitis in a sickle cell pt (likely pathogen and antibiotic choice(s))

Back 69

Likely pathogen: Salmonella, S. aureus, S. pneumonia
Abx: Cefotaxime/Ceftriaxone or FQ + Vancomycin

Front 70

Empiric tx of osteomyelitis in a pt w/ vascular insufficiency (likely pathogen and antibiotic choice(s))

Back 70

Likely pathogen: Gram (+), Gram (-), anaerobes
Abx: BL/BLI or Carbapenems or 3rd Gen Ceph or FQ + metronidazole/clindamycin all +/- vancomycin
Anaerobes: Cefoxitin or Clindamycin + ceftazidime

Front 71

Duration of abx tx of osteomyelitis

Back 71

o Prolonged therapy 4-6 wks

Front 72

Monitoring parameters for osteomyelitis

Back 72

• Clinical signs and symptoms
• CBC (WBC) – one or two times weekly until within normal range
• ESR and/or CRP – weekly or every other week (may take several weeks to normalize)
• MRI – repeat at end of therapy
• Chemistry panel – Follow BUN/SCr for agents eliminated renally
• Serum drug levels
• Adherence – critical for treatment success, both IV and oral, reinforce at every chance

Front 73

Which antimicrobials have bone penetration?

Back 73

o Clindamycin and rifampin
o Fluoroquinolones, linezolid, vancomycin, nafcillin/oxacillin, cephalosporins

Front 74

What pts are candidates for IV abx in tx of osteomyelitis?

Back 74

• Standard of care for adults
• Data lacking for PO therapy
• Limited data with fluoroquinolones and linezolid

Front 75

What pts are candidates for PO abx in tx of osteomyelitis?

Back 75

•Acceptable for pediatrics (more data to support)
• Suitable candidates
o Children with response to IV therapy
o Adults without DM or PVD

Front 76

Requirements for PO tx of osteomyelitis

Back 76

• Requirements for oral therapy
o Confirmed osteomyelitis
o Known C & S results
o Demonstrated improvement with IV therapy
o Suitable oral agent available
o Surgery performed (if needed)
o Adherence assured

Front 77

Principles of therapy of osteomyelitis

Back 77

o Need for surgical drainage must be assessed
o Remove foreign material (hardware)
o Must obtain C&S; empiric therapy → definitive therapy when results become available
o IV agents recommended (may be able to switch to oral)
o Bactericidal agents preferred
o Adequate bone penetration
o Prolonged therapy 4-6 wks
o Agent with long t1/2 and good tolerability (will be on home therapy)