SSTI

Question 1

What is the duration of therapy for cellulitis?

Answer 1

5-14 days

Question 2

What is the empiric treatment for pyomyositis?

Answer 2

Main pathogen: Staph aureus

Treat with vancomycin

Question 3

What is the treatment duration for impetigo? What agent should be used?

Answer 3

Topical agent BID x 5 days (mupirocin ointment)

Oral agent if multiple lesions x 7 days

*Avoid Bactrim as it lacks Group A strep activity

Question 4

How would you treat follicultis? Duration and agents?

Answer 4

Topical agents 2-4x daily x 7 days

• Clindamycin, erythromycin ointment, mupirocin ointment
• If PSA, use cipro or levo

Question 5

What empiric treatment is recommended for human bites?

Answer 5

Unasyn or Augmentin

*Avoid Clindamycin, first generation cephalosporins and macrolides as it has poor activity against Eikenella corrodens

Question 6

What empiric treatment is recommended for animal bites?

Answer 6

Augmentin or Doxy (PCN allergy)

Duration: 5-10 days, 7-14 days if severe

*Avoid Clindamycin, first generation cephalosporins and macrolides as it has poor activity against Pasteurella

Question 7

How would you treat a cat scratch?

Answer 7

Azithromycin for Bartonella henselae OR doxycycline for bacillary angiomatosis

Question 8

How would you treat a necrotizing infection due to Vibrio vulnificus?

Answer 8

Doxycycline + CTX

Question 9

How would you treat a necrotizing infection due to Aeromonas hydrophilia?

Answer 9

Doxycycline + CTX or cipro

Question 10

When should steroids be used for cellulitis and for how long should the steroids be given?

Answer 10

Prednisone 40 mg PO daily x 7 days in non-DM patients with cellulitis and multiple SIRS criteria

Question 11

When should cellulitis prophylaxis be given? What abx should be given for prophylaxis?

Answer 11

If 3-4 Strep episodes/year, consider oral PCN VK or IM benzathine PCN

Question 12

When should metronidazole be added as pre-op prophylaxis?

Answer 12

Surgeries in the biliary tract, appendectomy, colorectal, head/neck, urologic tract

Question 13

What is the pre-op timing for abx?

Answer 13

60 min prior to incision, 120 min for vancomycin and FQs

Question 14

What criteria requires intraop repeat administration?

Answer 14

Length of procedure (> 2 half-lives)
Obesity
Significant blood loss

Question 15

How would you manage a surgical site infection with no evidence of systemic response (no fever, WBC, HR, extending erythema)?

Answer 15

I & D only

Question 16

How would you manage a surgical site infection with evidence of systemic response? What are the systemic response criteria?

Answer 16

• T > 38.5
• WBC > 12 x 10^3 cells/mm^3
• HR > 110 BPM
• > 5 cm extending erythema or induration

I&D and 24-48 hrs of abx

*No need for abx if only fever up to 4 days after surgery

Question 17

What is the difference in pathogen prevalence between different stages of PJI?

Answer 17

Early (1-3 months after implantation) - Staph aureus, CoNS but also GNR and enterococcus in addition to polymicrobial

Delayted/late (> 3 months after implantation) - likely Staph aureus, CoNS, Strep spp and culture negative

Question 18

Describe the treatment phase and suppression phase in debridement and retain method in PJI with Staphlococcus?

Answer 18

Initial treatment: 2-6 weeks IV (4-6 weeks if no rifampin) + oral rifampin 600-900 mg daily

Treatment: 6 months total (knee) and 3 months (hips, shoulder, ankle)

Indefinite oral suppression

Question 19

Describe the treatment phase and suppression phase in 1- stage exchange method in PJI with Staphlococcus?

Answer 19

Initial treatment: 2-6 weeks IV (4-6 weeks if no rifampin) + oral rifampin 600-900 mg daily and then high oral bioavailability management

Treatment: 3 months for all joint sites

Indefinite oral suppression

Question 20

Describe the treatment phase and suppression phase in 2- stage exchange method in PJI with Staphlococcus?

Answer 20

4-6 weeks IV or high oral bioavailability with NO concurrent rifampin

Question 21

Describe the treatment phase and suppression phase in permanent resection method in PJI with Staphlococcus?

Answer 21

4-6 weeks IV or high bioavailability oral with no concurrent rifampin

Question 22

What is the treatment algorithm for non-Staph PJI for DAIR?

Answer 22

4-6 weeks IV or high oral bioavailability WITH

indefinite oral suppression

Question 23

What is the treatment algorithm for non-Staph PJI for 1 stage exchange?

Answer 23

4-6 weeks IV or high oral bioavailability WITH

indefinite oral suppression

Question 24

What is the treatment algorithm for non-Staph PJI for 2 stage exchange?

Answer 24

4-6 weeks IV or high oral bioavailability

Question 25

What is the treatment algorithm for non-Staph PJI for permanent resection?

Answer 25

4-6 weeks IV or high oral bioavailability

Question 26

What notable adverse effects does oritavancin have?

Answer 26

Osteomyelitis package insert warning | Rifampin drug interactions: CYP3A4/2D6 inducer, 2C9/2C19 inhibitor

Question 27

What is the spectrum activity of delafloxacin and what is its dosing PO/IV?

Answer 27

Staph including MRSA, Strep, Enterococcus faecalis and GNR including PSA 300 mg IV Q12H 450 mg PO Q12H

Question 28

What is the spectrum activity of omadacycline and what is its dosing PO/IV?

Answer 28

Staph including MRSA, Strep, Enterococcus faecalis and GNR including Enterobacter and Klebsiella 200 mg IV x day 1, 100 mg IV QD 450 mg PO x day 1 and 2, then 300 mg PO QD *Must fast 4 hours prior to administration

Question 29

How is mild DFI defined and treated?

Answer 29

Local infection involving skin/SQ tissue - < 2 cm surrounding erythema - Staph aureus, B hemolytic strep Oral treatment

Question 30

How is moderate DFI defined and treated?

Answer 30

Local infection involving deeper tissues (abscess, OM, fascitis) - > 2 cm surrounding erythema - < 2 systemic signs - Staph aureus, B hemolytic strep, GNR, anaerobes Use IV or oral

Question 31

How is severe DFI defined?

Answer 31

- Local infection involving deeper tissues (OM, abscess) - > 2 signs of SIRS (T > 38C, HR > 90 BPM, RR > 20, WBC > 12 x 10^3 - Prior abx use with no-PSA activity - Staph aureus, B hemolytic strep, GNR, anaerobes

Question 32

What is the empiric therapy for pediatric osteoarticular infections?

Answer 32

1st choice: Vancomycin or clindamycin due to high prevalence of Staph aureus infection

Question 33

What are the empiric treatment by age according to the European pediatric guidelines for osteoarticular infection?

Answer 33

Up to 3 months: Cefazolin + gentamicin or beta lactam + cefotaxime 3 months to 5 years: Cefazolin (covers Kingella kingae) or cefuroxime or clindamycin > 5 years - Anti-staph PCN or cefazolin or clindamycin

Question 34

What is the treatment duration for septic arthritis and OM in pediatric patients?

Answer 34

Septic arthritis: 2-4 days of IV therapy with a total of 2-3 weeks OM: 3-4 days of IV therapy with a total of 3-4 weeks