Skin and Soft Tissue Infections (SSTIs)

Question 1

Cutaneous abscesses : What are some commonly associated pathogens? (2)

Answer 1

S.Aeureus (Including MRSA) , Gram negative bacilli

Question 2

Cellulitis (purulent/non purulent ) : Whats commonly associated pathogens?

Answer 2

Non : Beta hemolytic streptococci

Purulent : also consider S.aureus (including MRSA)

Question 3

Surgical Site Infections : Commonly associated pathogens?

Answer 3

S.Aureus (including MRSA). coagulase-negative staphylococci, enterococc spp, e coli.

Question 4

Define a Moderate SSTI ?

Severe : Purulent vs non-purulent

Answer 4

WIth systemic signs and symptoms

Purulent : Fever >38C, HR>90, RR>24, WBC >12 or <4 or immunocomp

NON : Fever >38C, HR >90, RR>24, WBC >12 or <4, immunocomp, failed oral therapy or skin sloughing with signs of a deeper infection

Question 5

Impetigo :

1) Superficial infection most common in ?
2) Usually preceded by ? (3)

3) Can be __ or __

Answer 5

1. children (epidermis)
2. Minor skin abrasion
   -small cuts
   -insect bites
3. bullous or non bullous

Question 6

Impetigo Pathogens Gram +

1) Bullous pathogen

2) Non Bullous? (2)

Answer 6

1. Staph aureus (MRSA, MSSA)

2) S.Aureus and Streptococc pyogenes (May be mixed infection with both)

Question 7

Ecthyma

1) Similar to impetigo but deeper into ?
2) More commonly found where?
3) Can be more aggressive in which pt’s?

4) Pathogens?

Answer 7

1. Dermis
2. lower extremities
3. immunocomp
4. S.pyogenes, and S.Aureus

Question 8

TX Impetigo and Ecthyma :

1) Empiric tx should cover both ?

2) When would topical therapy be innapropriate?

Answer 8

1. MSSA and Streptococci
2. Not during outbreaks or pt’s with numerous lesions (systemic therapy preferred)

Question 9

TX Impetigo and Ecthyma :

1) What are the six agents u can use, and state what thhey cover!

Dont care, dont care, be mean

Answer 9

1. Diclox - MSSA and Streptococci
2. Cephalexin - MSSA and Streptococci
3. Doxycycline - CA-MRSA ; poor streptoccocal coverage. Option in PCN allergic pt’s
4. Clindamycin - Covers CA-MRSA; option in pcn allergic pt’s
5. BACTRIM - CA-MRSA; poor streptococc coverage ; option in pcn allergic pt’s
6. Mupirocin

Question 10

Ecthyma Gangrenosum

-Fulminant GNR Septicemia that’s usually ?
-Which characteristic of the usual host?

Furuncles and Carbuncles
1. Infection of the ?
2. Common pathogens?
3. TX of small and large furuncles?
4. Whats usually not needed?
5. What reduces skin inoculum?

Answer 10

1. Pseudomonas
2. Immunocomp!
3. Hair follicle
4. S. aureus
5. may rupture after applying moist heat, large tx with incision and drainage
6. Systemic abx
7. Chlorhexidine soap

Question 11

Cutaneous Abscesses

1. Collection of what under dermis?
2. What pathogen mainly?
   3) Tx ?

Answer 11

1. Pus
2. S.Aureus (including MRSA)
3. Incision and drainage alone. Culture if systemic abx are needed

Question 12

What are the indications for abx therapy for purulent cellulitis/abscess?

1. Rapidly ___ cellulitis or _____
2. Extensive abscess how large?
3. Systemic signs of infection such as?
4. Extremes of?
5. I__ , comorbidities
   -quantitative __ or qualitative ___, esp if poorly controlled
6. Difficult to __ area such as ?
7. Failure of ?

Answer 12

1. progressive, septic thrombophlebitis
2. > 5cm diameter
3. Fever, leukocytosis, leukopenia
4. Age
5. Immunosuppression , neutropenia
   -neutropenia-diabetes
6. drain, face, hands, genitalia
7. Prior incision and drainage

Question 13

What are 3 examples of non purulent SSTI?

Answer 13

1) Erysipelas
2) cellulitis
3) Necrotizing infections

Question 14

Cellulitis : Sx’s (6)
We turn every pancake slowly everyday

Answer 14

Warmth, tenderness, erythema, petichiae, swelling, ecchymoses

Question 15

Pathogens for Non Purulent Cellulitis :

1) Most common
2) Less common ?

Answer 15

1. Streptococci
   -Group A strep (S. pyogenes)
2. Staphylococci
   -usually associated w/penetrating injury
   -MRSA IS VERY UNCOMMON

Question 16

TX CELLULITIS :

1. What are the six agents? and their coverage
2. TX duration ?
3. Are blood cultures needed in non severe infections?
4. Whats generally not used?

Answer 16

1. penicillin - used if streptoccoci r suscpetible, no appreciable s.aureus coverage
2. Cephalexin - Streptoccoci, MSSA
3. Clindamycin (IV/PO) - Streptococci , MSSA, CA-MRSA
4. Cefazolin - streptococc, MSSA
5. Diclox - streptococci and MSSA
6. Amox +/- clavulanate - streptococci, adds MSSA coverage with Amox clav
7. 5-10 days; 5 days adequate based on clin response
8. No
9. Needle aspiration

Question 17

Necrotizing Fasciitis :

1) What is paramount ?
2) Pathogens?
-Describe polymicrobial vs monomicrobial infxns

Answer 17

1) Surgical intervention

2) Poly : Synergistic aerobic + anaerobic

Mono : S.pyogenes most common
-S.Aureus (CA-MRSA)
-Clostridium Spp- Associated w/colon cancer
- Vibrio Vulnificus (gram neg rod)
-Aeromonas Hydrophilia (gram neg rod)

Question 18

Empiric Tx : Necrotizing Fasciitis

-Empiric tx should be broad

1) MRSA coverage? (3)
2) Broad gram neg WITH anaerobic coverage?
3) Add ___

Answer 18

1. VANCO, DAPTO, or LINEZOLID
2. Piperacillin-tazobactam
   -carbapenem
   -Ceftriaxone plus metro
3. Clindamycin

Question 19

Kim see chart for directed therapy for necro fasciitis

Answer 19

See chart

Question 20

Fournier Gangrene : (4) pathogens?

Answer 20

1. S.aureus,
   -P.auruginosa,
   -entercobacter ( e.coli , Klebsiella) ,
   -anaerobes

Question 21

Bite Wounds : Which pathogens can cause this? (9)

Answer 21

1. Streptococci
2. s.aureus
3. Eikenella corrodens (human bites)
4. Bartonella (cats) - chronic
5. Pasturella multocida (dogs and cats) -acute
6. Hemophilus
7. Anaerobes
8. Rabies
9. Tetanus

Question 22

Empiric Tx for Bites

1) State the 4 agents and what they cover

Answer 22

1) Augmentin - Pasturella, eikenella

2) Doxycycline - pasturella, and eikenella. Poor streptococc coverage

3) Levoflox - covers pasturella

4) Moxiflox - covers Pasturella and anaerobes

Question 23

Concomitant therapy with Zosyn and vanco has been linked to an incr risk of?

Answer 23

Nephrotoxicity

Question 24

Classic signs of Diabetic Foot Infection :
1) How many will u need for a diagnosis?
2) STate the signs
3) What are the secondary signs? (4)

Answer 24

1. > =2
2. Inflammation (red, warm, swelling, tenderness, pain)
   - purulent drainage
3. Non-purulent secretions
   -discolored granulation tissue
   -foul odor
   -undermining of wound edges –> wound extending beyond edges

Question 24

Pathogens : 1) Aeorbic gram pos cocci such as? 2) Aerobic gram neg bacilli such as? 3) Anaerobes --> not major pathogens in __ or __ infxns

Answer 24

1. MSSA/MRSA 2. P.aeruginosa after abx failure 3. mild, moderate

Question 24

MILD DFI's : TX 1) Most common pathogens? 2) Tx with oral agents such as ? (6) MOD DFI TX : 1) Broader spectrum including ? 2) Oral or IV Agents such as? (7) -see chart kim Severe DFI TX : -See chart

Answer 24

1. S.aureus, streptocco spp 2. clinda, keflex, levoflox, augmentin, doxy, bactrim 1) Gram negs 2) Levo, moxi, clinda+cipro, ceftriaxone, cefoxitin, ampiciillin-sulbactam, MRSA coverage based on risk factors

Question 25

Risk factors for Pseudomonas? (4) Duration of therapy for DFI's ?

Answer 25

- High local prevalence of pseudo infections -Infxn occurs in warm climate -freq exposure of infected foot to water -PRIOR abx exposure Total of 1-4 weeks Mild : 1-2 weeks Mod : 1-3 wks Severe : 2-4 weeks

Question 25

Osteomyelitis : 1) ACute hematogenous - How long parenteral therapy? -Most common pathogen and high PP of ? -What if it is worse in 48 hrs? 2) Chronic and Direct Extension -How long abx therapy? -WHat kind of intervention?

Answer 25

1. 6 weeks -s.aureus , endocarditis -surgical debridement ( + blood cx, rising CRP) 2. 4-6 wks -Surgical debridement

Question 25

Blood Tests for Osteomyelitis 1. CRP? 2. ESR? 3. Blood culture?

Answer 25

1. >3.2 mg/dL 2. >60 mm/hr 3. >50% yield

Question 26

Pathogens : Osteomyelitis Name 6 Name 1 pathogen most common in sickle cell disease pt's What should the empiric tx cover? Duration of TX : 4. No residual infected tissue -Residual soft tissue infection -Residual viable infected bone -No surgery or residual dead bone

Answer 26

1. S.aureus (MSSA, or MRSA most common) -S.epidermidis -e coli -klebsiella -proteus spp. -Pseudomonas 2. Salmonella Spp 3. MRSA, Enterobacter, +/- Pseudomonas 4. 2-5 days 1-3 weeks 4-6 weeks >= 3 months