SSTI, DFI, BJI Flashcards
What are the classifications of skin infections?
- Purulent
- Non-purulent
Purulent skin infections common organism
- Staphylococcal -> MSSA, MRSA
- if you have pus, it’s most likely this organism
Non-purulent skin infections common organism
Streptococci
What are the classifications of purulent SSTI’s?
mild, moderate, and severe
Treatment for mild purulent SSTI’s
- Incision and drainage (I and D) alone in most cases
- Warm moist compresses
- Antibiotic therapy under certain conditions
For mild purulent SSTI’s, what are the conditions that would require antibiotic therapy?
- Abscess in area difficult to completely drain
- Associated comorbidities or immunosuppression
- Associated septic phlebitis
- Extremes of age
- Lack of response to I and D alone
- Severe or extensive disease
- Signs and symptoms of systemic illness
Treatment for moderate purulent SSTI’s
- I and D with empiric oral antibiotics directed against CA-MRSA -> Clindamycin, doxycycline, Bactrim
- If MSSA is isolated -> Cephalexin, Dicloxacillin
- Warm moist compresses
Treatment for severe purulent SSTI’s
- I and D and intravenous antibiotics directed against MRSA -> Ceftaroline, Dalbavancin / oritavancin / telavancin, Daptomycin, Linezolid / tedizolid, Vancomycin
- If MSSA is isolated -> Cefazolin, clindamycin, oxacillin, nafcillin (clinda will not be used first)
- Warm, moist compresses
Treatment for mild non-purulent SSTI’s
- Oral antibiotics (outpt) targeting streptococci (may also want to target staphylococci) -> Penicillin VK, Cephalexin, Clindamycin, Dicloxacillin (use clinda and dicloxa if you’re concerned about staph)
- Immobilization and elevation of the affected extremity
Treatment for moderate non-purulent SSTI’s
- IV antibiotics (inpt) -> Penicillin G, Cefazolin, Ceftriaxone, Clindamycin
- Switch to oral therapy once there is clinical response (oral Keflex)
- Immobilization and elevation of the affected extremity
For a moderate infection, if you are concerned about MRSA, which agents would you use?
- Ceftaroline
- Dalbavancin
- Daptomycin
- Linezolid
- Oritavancin
- Tedizolid
- Telavancin
- Vancomycin
Treatment for severe non-purulent SSTI’s
- Surgical debridement and IV antibiotics (want to cover anaerobe and gram -)
- Vancomycin + imipenem-cilastatin
- Vancomycin + meropenem
- Vancomycin + piperacillin-tazobactam
- Immobilization and elevation of the extremity
Duration of therapy for SSTI’s
- Outpatients: 5 days; may extend if slow to respond to therapy
- Inpatients: 7-10 days
Patient education for SSTI’s
- Cover any draining wounds with clean and dry bandages
- Bathe regularly
- Clean hands regularly
- Clean hands after touching area of infection or any item that has been in contact with a draining wound
- Avoid reusing or sharing any personal items that may have contacted the infected site
What are the newer agents for SSTI’s?
- Tedizolid
- Telavancin
- Dalbavancin / oritavancin
- Delafloxacin
- Omadacycline
- Guidelines unclear about place in therapy for these agents
What is the biggest limitation for SSTI agents?
cost
Which organisms cause Necrotizing Fasciitis?
- Mono- or polymicrobial
- S. pyogenes (“flesh-eating” bacteria)
- S. aureus (less common than strep)
- Vibrio vulnificus, Aeromonas hydrophila
- Anaerobic streptococci (Peptostreptococcus)
(general) treatment of Necrotizing Fasciitis
- Immediate surgical debridement!
- Repeat surgical debridement
- Antibiotic therapy active against aerobes (MRSA) and anaerobes
How long do you continue treatment for Necrotizing Fasciitis?
- Continue treatment until debridement is no longer needed
- Clinical improvement has occurred
- Afebrile for 48-72 hours
What are the agents that you use for empiric therapy for Necrotizing Fasciitis and Fournier Gangrene?
- One of these: Vancomycin, Daptomycin, Linezolid
- And one of these: Piperacillin / tazobactam, Imipenem / cilastatin, Meropenem, Doripenem, Ertapenem, Ceftriaxone AND metronidazole, Fluoroquinolone AND metronidazole
Which organisms are involved with necrotizing infections specifically Fournier Gangrene?
- Mixed
- MSSA and MRSA
- Pseudomonas
Which organisms are responsible for impetigo?
- MSSA
- MRSA
- Beta-hemolytic streptococci
What is the treatment for impetigo?
- Topical for localized infection: mupirocin or retapamulin twice daily for 5 days
- New topical drug: ozenoxacin (MSSA, MRSA, Strep. pyogenes) twice daily for 5 days
- Empiric treatment for systemic symptoms or multiple lesions (MSSA & S. pyogenes coverage): dicloxacillin, cephalexin, amoxicillin-clavulanate for 7 days
- If MRSA suspected/confirmed: sulfamethoxazole-trimethoprim, doxycycline, or clindamycin
- Local care: soaking in warm water to facilitate crust removal
Which organism are involved in animal and human bite wounds?
- Mouth flora: anaerobes
- Victim’s skin flora: staphylococci and streptococci
- Purulent wounds are most likely to be: Polymicrobial, Aerobes. and anaerobes
- Non-purulent are most likely to be: Streptococci, Staphylococci
- Pasteurella spp. (animal bites)
- Eikenella corrodens (human bites)
What are the two drugs of choice (IV and PO) for animal and human bite wounds?
- Oral: Amoxicillin / clavulanate
- Intravenous: Ampicillin / sulbactam
- If using alternate therapy, just make sure that you have anaerobic and staph coverage
What is the duration of treatment of infected bite wounds?
- 5-10 days of oral antibiotic therapy
* Intravenous therapy for 7-14 days
What are the classifications of diabetic foot infections (DFI)?
- Mild
- Moderate
- Severe
Mild diabetic foot infections (DFI)
- Local infection involving only the skin and the subcutaneous tissue
- If erythema is present, must be greater than 0.5 cm but less than or equal to 2 cm
- Exclude other causes of inflammatory skin response (trauma, gout, etc.)
Moderate diabetic foot infections (DFI)
- Local infection involving only the skin and the subcutaneous tissue
- Erythema greater than 2 cm or involving structures deeper than skin and subcutaneous tissues (abscess, osteomyelitis, septic arthritis, fasciitis) AND no systemic inflammatory response signs (described below)
Severe diabetic foot infections (DFI)
Local infection (as described above) with signs of SIRS as manifested by greater than 2 of the following:
- Temperature > 38 C or < 36 C
- Heart rate > 90 bpm
- Respiratory rate > 20 breaths/min or PaCo2 < 32 mmHg
- WBC > 12,000 or < 4000 cells/microliter or greater than or equal to 10% immature forms (bands)
Define local infection
Presence of at least 2 of the following: • Local swelling or induration • Erythema • Local tenderness or pain • Local warmth • Purulent discharge
Treatment Considerations for DFIs
- Is there evidence of infection?
- Is the infection mild, moderate, or severe?
- Is there high risk of MRSA?
- Has the patient received antibiotics in the past month? (If so, include agents active against gram-negative bacilli)
- Are there risk factors for Pseudomonas infection?(Local prevalence, Warm climate, Exposure of foot to water)
What are possible pathogens for mild DFI?
- Staphylococcus aureus (MSSA)
- Streptococcus spp.
- Methicillin-resistant S. aureus (MRSA)
What are treatment for mild DFI?
- Dicloxacillin
- Clindamycin
- Cephalexin
- Levofloxacin
- Amoxicillin-clavulanate
- Doxycycline
- SMX/TMP
Duration of therapy for mild DFI
1-2 weeks
What are possible pathogens for moderate DFI?
- MSSA
- Streptococcus spp.
- Enterobacteriaceae
- Obligate anaerobes
- MRSA
- Pseudomonas aeruginosa
What are treatment for moderate DFI?
- Levofloxacin
- Cefoxitin
- Ceftriaxone
- Ampicillin-sulbactam
- Moxifloxacin
- Ertapenem
- Tigecycline
- Levofloxacin AND clindamycin
- Ciprofloxacin AND clindamycin
- Imipenem-cilastatin
- Linezolid
- Daptomycin
- Vancomycin
- Piperacillin / tazobactam
- Ceftazidime
- Cefepime
- Aztreonam
- Imipenem-cilastatin
- Meropenem
- Doripenem
Duration of therapy for moderate DFI
1-3 weeks
What are possible pathogens for severe DFI?
- MRSA
- Enterobacteriaceae
- Pseudomonas
- Anaerobes
What are treatment for severe DFI?
Vancomycin (or daptomycin or linezolid) AND one of the following:
- ZOSYN
- IMIPENEM-CILASTATIN
- Ceftazidime
- Cefepime
- Aztreonam
- Meropenem
- Doripenem
Duration of therapy for severe DFI
2-4 weeks
What are other factors that need to be taken into consideration when treating DFI?
- Glycemic control
- Duration of therapy
- Surgical involvement
- Wound care
- Imaging for osteomyelitis: if there is residual, but viable infected bone treat 4-6 weeks (IV preferred) unless linezolid is an option (has excellent bioavailability)
Microbiology of bone and joint infections: septic arthritis
- Staphylococci
- Streptococci
- Enterococci
What is the treatment and duration of therapy of bone and joint infections: septic arthritis?
- Gram-positive directed therapy: Vancomycin, Daptomycin, Linezolid
- Gram-negative bacilli: Vancomycin AND Ceftriaxone
- Duration of therapy is 14-28 days
Microbiology of bone and joint infections: Osteomyelitis
- Staphylococcus aureus
- Coagulase-negative Staphylococcus
- Streptococci
- Enterococci
- Gram-negative organisms (secondary to DFI)
- Anaerobes (secondary to DFI)
- Mycobacterium and fungal—rarely
What is the treatment and duration of therapy of bone and joint infections: osteomyelitis?
- Wait for cultures before starting antibiotic therapy
- Surgical debridement or bone biopsy
- Therapy should be determined based on suspected organisms and modified based on culture and sensitivity results
- Duration of therapy is at least 4-6 weeks (8 weeks for MRSA) and up to 3 months
- Vertebral osteomyelitis should be treated for 6-12 weeks
What is the treatment and duration of therapy of prosthetic joint infections: specific to Staphylococci?
• Debridement and retention of prosthesis:
- IV antibiotics AND rifampin followed by
- Oral antibiotics AND rifampin for 3 months (hip, elbow, or shoulder) or 6 months (knee)
- Oral antibiotics: fluoroquinolone, minocycline, doxycycline, SMX/TMP, cephalexin, or dicloxacillin
• Treatment after resection arthroplasty
- 4-6 weeks of IV or highly bioavailable oral therapy
What are the possible organisms in Prosthetic Joint Infections?
- Staphylococci (MSSA or MRSA)
- Streptococci
- Enterococci
What is the treatment for Prosthetic Joint Infections: MSSA Staphylococci?
- Nafcillin
- Oxacillin
- Cefazolin
What is the treatment for Prosthetic Joint Infections: MRSA Staphylococci?
Vancomycin
What is the treatment for Prosthetic Joint Infections: Streptococci?
- Ampicillin
- Ceftriaxone
What is the treatment for Prosthetic Joint Infections: Enterococci?
Ampicillin
If a patient has a PCN allergy, which antibiotic can be used? (for Prosthetic Joint Infections)
vancomycin
