1. Inpatient Skin and Soft Tissue Infections
Keri Holmes-Maybank, MD
Medical University of South Carolina
September, 2012

2. Objectives
Identify appropriate empiric antibiotics for treatment of SSTI’s.
Identify appropriate antibiotics for deescalation of SSTI treatment.
Recognize patients appropriate for inpatient hospitalization of SSTI’s.
Recognize appropriate use of blood cultures, needle aspiration and punch biopsies in SSTI’s.

3. Key Messages
Blood culture for skin and soft tissue infections are extremely low yield, approximately 5%.
Consider hospitalization for patients with systemic signs of illness.
MRSA infections have led to an increase in skin and soft tissue infections.
Using guidelines for skin and soft tissue infections leads to a decrease in the emergence of antibiotic resistance.

4. SSTI’s Increasing ER visits and hospitalizations
29% increase in admissions, 2000 to 2004
Primarily in age <65
Presume secondary to community MRSA
50% cellulitis and cutaneous abscesses
Estimated $10 billion SSTI 2010

5. IDSA Guidelines
“Practice guidelines are systematically developed statements to assist practitioners and patients in making decisions about appropriate health care for specific clinical circumstances.”

6. Guidelines Reduce emergence of resistant organisms
Reduce hospital days
Reduce costs:
Blood cultures
Consultations
Imaging
Hospital days
2011-Implementation of treatment guidelines
Decreased use of blood cx
Decreased advanced imaging
Decreased consultations
Shorter durations of therapy
Decreased use of anti-pseudomonal
Decreased use of broader spectrum abx
No change in adverse outcomes
Decreased costs

7. Inpatient Hospitalization
Systemic illness
HR >100 and
Temp >38oC or <36oC and
Systolic bp <90 or decrease of 20 mmHg < baseline
Hypotension and
CRP>13
Marked left shift
Elevated creatinine
Low serum bicarbonate
CPK 2 x the upper limit of normal

8. Inpatient Hospitalization
Rapid progression of cellulitis
Worsening infection despite appropriate antibiotics
Tissue necrosis
Severe pain
Altered mental status
Respiratory, renal or hepatic failure
Co-morbidities:  immune compromise, neutropenia, asplenia, preexisting edema, cirrhosis, cardiac failure, renal insufficiency

9. Obtain Careful History
Immune status
Geographic locale
Travel history
Recent trauma or surgery
Previous antimicrobial therapy
Lifestyle - occupation
Hobbies
Animal exposure
Bite exposure

10. Testing Blood cultures positive <5% Needle aspiration 5-40%
Punch biopsy 20-30%

11. Blood Cultures HR >100 , Temp >38oC and <36oC, Sys <90mmHg
Lymphedema
Immune compromise/neutropenia/malignancy
Pain out of proportion to exam
Infected mouth or eyes
Unresponsive to initial antibiotics
Water-associated cellulitis
Diabetes
Recurrent or persistent cellulitis
Concern for a cluster or outbreak

12. Needle Aspiration or Skin Biopsy
HR >100 , Temp >38oC and <36oC, Sys<90mmHg
Hypotension and
CRP>13 Marked left shift
Elevated creatinine Low serum bicarb
CPK 2 x upper limit of normal
Immune compromise/neutropenia/malignancy
Diabetes
Animal or human bite wounds

13. SSTI Indicators of more severe disease: Low sodium Low bicarb
High creatinine
New anemia
Low or high wbc
High CRP (associated with longer hospitalization)

14. Empiric Anti-MRSA Antibiotics
Recent hospitalization
Residence in long term care facility
Recent antibiotic treatment
HIV
Men who have sex with men
Injection drug use
Hemodialysis
Incarceration
Military service
Sharing needles, razors, sports equipment
Diabetes

15. Deescalation Acute skin findings resolving Afebrile
No signs of systemic illness
Should see systemic signs improvement by 48 hours
Should see skin improvement 3-5 days by at the latest

16. Broaden Antibiotics If no improvement in systemic signs in 48 hours
If no improvement in skin in 72 hours
As antibiotics kill organisms, toxins released may cause a worsening of skin findings in first 48 hours

17. Cellulitis 65% relative increase since 1999
600,000 admissions annually

18. Risk Factors for Cellulitis
Obesity
Edema
Venous insufficiency
Lymphatic obstruction
Fissured toe webs
Maceration
Fungal infection
Inflammatory dermatoses – eczema
Repeated cellulitis
Subcutaneous injection or illegal drugs
Previous cutaneous damage
All lead to breaches in the skin for organism invasion

19. Surgical Risk Factors Saphenous venectomy
Axillary node dissection for breast cancer
Gyn malignancy surgery with lymph node dissection *** in conjuction with XRT
Liposuction

20. Non-Purulent Cellulitis
No purulent drainage, no exudate, no associated abscess
beta hemolytic streptococci
Antibiotics:
Nafcillin
Cefazolin
Ceftriaxone 
Clindamycin
Vancomycin
Modify to MRSA coverage if
No improvement in skin findings within 72 hours
Signs of severe systemic illness

21. Non-Purulent Cellulitis
Deescalation:
 Penicillin
Amoxicillin
Amoxicillin/clavulanate
Cephalexin
Treatment duration:
Discontinue abx 3 days after acute inflammation disappears
Usually 5-10 days of treatment

22. Purulent/Complicated Cellulitis
Purulent drainage
Exudate
Absence of a drainable abscess
Deeper tissue - surgical/traumatic wound infection, major abscess, infected ulcer or burn

23. Purulent/Complicated Cellulitis
MRSA coverage
Antibiotics:
Vancomycin
Clindamycin
Linezolid (restricted to ID)
Daptomycin (restricted to ID)

24. Purulent/Complicated Cellulitis
Deescalation:
Clindamycin
Trimethoprim/sulfamethoxazole
Linezolid (restricted to ID)
Treatment duration:
Discontinue abx 3 days after acute inflammation disappears
Usually 5-10 days of treatment

25. Secondary Treatment of Cellulitis
Elevation of affected leg
Compression stockings
Treat underlying tinea pedis, eczema, trauma
Keep skin well hydrated

26. Confused with Cellulitis
Acute dermatitis
Gout
Herpes zoster
Lipodermatosclerosis
Deep vein thrombosis
Contact dermatitis
Drug reaction
Foreign body reaction

27. Abscess

28. Abscess
ALWAYS, ALWAYS
Incision and drainage
Culture aspirate

29. Abscess –When to Add Antibiotics
Multiple sites of infection
Rapid progression in presence of cellulitis
Systemic illness (fever, hypotension, tachycardia)
Immune compromise
Elderly
Difficult to drain area (hand, face, genitalia)
Lack of response to incision and drainage
Septic phlebitis - multiple lesions
Gangrene

30. Abscess Antibiotic Coverage
MRSA coverage:cellulitis, severe disease, rapid progression, septic phlebitis, constitutional symptoms, difficult to drain
Antibiotics:
Vancomycin
Clindamycin
Daptomycin (restricted to ID)
Linezolid (restricted to ID)
c-MRSA or beta hemolytic streptococci
Antibiotics
Trimethoprim/sulfamethoxazole + beta lactam
Doxycycline + beta lactam

31. Abscess Deescalation: Treatment duration: Clindamycin
Trimethoprim/sulfamethoxazole
Linezolid (restricted to ID)
Treatment duration:
Discontinue abx 3 days after acute inflammation disappears
Usually 5-10 days of treatment

32. Animal Bites

33. Animal Bites Pasteurella – mc organism Antibiotics:
Ampicillin/sulbactam
Piperacillin/tazobactan
Cefoxitin
Meropenem
Ertapenem (restricted to ID and Surgery)
Tetanus toxoid (if not up to date)

34. Animal Bites Deescalation Treatment duration: Amoxicillin/clavulanate
Doxycycline
Treatment duration:
Discontinue abx 3 days after acute inflammation disappears
Usually 5-10 days of treatment

35. Human Bites

36. Human Bite Antibiotics: Tetanus toxoid (if not up to date)
Ampicillin/sulbactam
Meropenem
Ertapenem (restricted to ID and Surgery)
Tetanus toxoid (if not up to date)
Closed fist***
Cefoxitin
Ertapenem(restricted to ID and Surgery)
Hand surgery consult***

37. Human Bites Deescalation: Treatment duration: Amoxicillin/clavulanate
Moxifloxacin + clindamycin
Trimethoprim/sulfamethoxazole + metronidazole 
Treatment duration:
Discontinue abx 3 days after acute inflammation disappears
Usually 5-10 days of treatment if no joint or tendon involvement

38. Surgical Site Infection

39. Surgical Site Infection
Pain, swelling, erythema, purulent drainage
Usually have no clinical manifestations for at least 5 days after operation
Most resolve without antibiotics
Open all incisions that appear infected >48 hours after surgery
No antibiotics if temperature <38.5oC and HR <100 bpm

40. Surgical Site Infection
If temperature >38.5oC or HR >100 bpm:
Trunk, head, neck, extremity
Cefazolin
Clindamycin
Vancomycin if MRSA is suspected
Perineum, gi tract, female gu tract
Cefotetan
Ampicillin/sulbactam
Ceftriaxone + metronidazole or clindamycin
Fluoroquinolone + clindamycin
Treatment duration:
Usually hours or for 3 days after acute inflammation resolves

41. Neutropenia and SSTI’s

42. Neutropenic Patients with SSTI
ALWAYS blood CULTURES
Initial infection - <7 days neutropenia
Antibiotics
Carbapenems
Cefepime
Ceftazidine
Piperacillin/tazobactam
PLUS
Vancomycin
Linezolid (restricted to ID)
Daptomycin (restricted to ID)
(discontinue if culture negative after hours)  

43. Neutropenic Patients with SSTI
Subsequent infection- >7days neutropenia (fungi, viruses, atypical bacteria)
Treatment:
Amphotericin B
Micafungin (may require higher dose and ID consult)
Voriconazole (restricted to ID, Heme/Onc, Critical Care, Pulmonary, and Transplant)
PLUS
Carbapenems
Cefepime
Ceftazidine
Piperacillin/tazobactam
Vancomycin
Linezolid (restricted to ID)
Daptomycin (restricted to ID)
(discontinue if culture negative after hours)

44. Neutropenic Patients with SSTI
Deescalation:
Ciprofloxacin and amoxicillin/clavulanate
Treatment duration:
At least 7 days

45. Vascular-Access Devices in Neutropenia
Device predisposes to SSTI
66% Gram positive
Entry site infection
Antibiotics
Tunnel infection and vascular port-pocket infection
Device removal and antibiotics

46. Diabetic Foot Ulcers

47. Infected Diabetic Foot Ulcers
Not all diabetic foot ulcers are infected.
Indications of infection:
Purulent secretions OR
2 of manifestations of inflammation:
Redness
Warmth
Swelling/induration
Pain/tenderness

48. Diabetic Foot Ulcers Common, complex, costly
Largest number of diabetes related hospital bed days
Most common proximate, non-traumatic cause of amputations

49. Diabetic Foot Ulcers
Always obtain specimen (biopsy, ulcer curettage, aspiration) and treat with antibiotics and wound care
Mild ulcer
Cellulitis or erythema extends <2cm around ulcer, infection limited to skin
Antibiotics:
Clindamycin
Cephalexin
Amoxicillin/clavulanate
Trimethoprim/sulfamethoxazole
Treatment duration
Usually 1-2 weeks treatment

50. Diabetic Foot Ulcers Moderate or Severe ulcer Antibiotics:
Cellulitis or erythema extends >2cm around ulcer, fever, ams, hypotension, leukocytosis, acidosis, severe hyperglycemia
Antibiotics:
Vancomycin and ceftazidime
(consider adding metronidazole, piperacillin/tazobactam, meropenem)
Deescalation:
Moxifloxacin
Amoxicillin/clavulanate
Trimethoprim/sulfamethoxazole
Treatment duration:
Usually 2-4 weeks of treatment

51. Secondary Treatment of Diabetic Foot Ulcers
Wound care
Debridement
Glycemic control
Evaluate vascular status

52. References
Gunderson CG. Cellulitis: Definition, etiology, and clinical features. Am J Med2011;124:  
Jenkins TC, et al. Decreased antibiotic utilization after implementation of a guideline for inpatient cellulitis and cutaneous abscess.  Arch Intern Med. 2011;171(12):
Rajan S. Skin and soft-tissue infections: Classifying and treating a spectrum. Cleveland Clinic Journal of Medicine. 2012;79(1):57-66. 
Swartz MN. Cellulitis. N Engl J Med 2004;350:  
IDSA GUIDELINES:
Lipsky BA, et al. Diagnosis and treatment of foot infections. Clin Infect Dis  2004;39:
Liu C, et al. Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis 2011;52(3):e18- e55.
Stevens DL, et al. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis  2005;41: