Inpatient Skin and Soft Tissue Infections

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

2. Skin and Soft Tissue Infections • Cellulitis • Impetigo • Erysipelas • Abscess • Animal bite • Human bite • Surgical site infection • Necrotizing fasciitis

3. Skin and Soft Tissue Infections • 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

4. IDSA Guidelines MUSC Antibiotic Stewardship & Anti-Infective Subcommittee • “Practice guidelines are systematically developed statements to assist practitioners and patients in making decisions about appropriate health care for specific clinical circumstances.”

5. 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 • Decreased costs • No change in adverse outcomes

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

7. Inpatient Hospitalization • Abnormally 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

8. Skin and Soft Tissue Infections • Indicators of more severe disease: • Low sodium • Low bicarb • High creatinine • New anemia • Low or high wbc • High CRP (associated with longer hospitalization)

9. Cultures • Blood cultures positive <5% • Needle aspiration 5-40% • Punch biopsy 20-30%

10. 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

11. Needle Aspiration or Skin Biopsy • HR >100 , Temp >38oC and <36oC, Sys<90mmHg • 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

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

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

14. 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

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

16. 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

17. Post-Surgical Risk Factors • Saphenousvenectomy • Axillary node dissection for breast cancer • Gyn malignancy surgery with lymph node dissection *** in conjuction with XRT • Liposuction

18. Cellulitis • CBC with diff • BMP • Blood cultures • Culture aspiration of leading edge of cellulitis

19. Non-Purulent Cellulitis • INTACT SKIN • No purulent drainage, no exudate, no associated abscess • Beta hemolytic streptococci • Antibiotic: • Cefazolin • Documented anaphylactic cephalosporin allergy - Vancomycin

20. Non-Purulent Cellulitis • Deescalation: • Cephalexin • Beta-lactam anaphylaxis - clindamycin • 5 days of treatment

21. Purulent/Complicated Cellulitis • BROKEN SKIN • Purulent drainage • Exudate • Absence of a drainable abscess

22. Purulent/Complicated Cellulitis • MRSA coverage • Antibiotics: • Vancomycin

23. Purulent/Complicated Cellulitis • Deescalation: • Trimethoprim/sulfamethoxazole + cephalexin • Beta lactam anaphylaxis – clindamycin • Sulfa allergy – tetracycline or doxycycline • If sulfa and beta lactam allergies - linezolid • 5 days of treatment

26. Empiric SSTI algorithm *This algorithmdoes NOTinclude: surgical site infections, diabetic foot ulcers, decubitus ulcers, insect, animal or human bites, or gangrene **Please see order form for guidance (including renal dosing adjustments) If cephalosporin allergic: Vancomycin can be substituted for cefazolin 1 The preferred method of treatment is I&D Clinical Pearl: Treatment should continue for 48 hours prior to determination of clinical failure; SSTIs often appear worse during initial treatment period

27. Antibiotic De-escalation Criteria • Culture susceptibilities • Clinical response • Clinically stable • Decreased erythema • Decreased edema • Decreased warmth • Resolving leukocytosis • Afebrile Total course of antibiotics is 5 days (i.e. 2 days of IV cefazolin + 3 days of PO cephalexin) Note: Renal dose adjustments are required for patients with CrCL less than 30 mL/min If sulfa allergic: Either tetracyclineor doxycycline can be substituted to replace TMP/SMX If beta-lactam anaphylaxis: Clindamycin (non-severe infection) can be substituted to replace cephalexin, or linezolid can be substituted to replace both TMP/SMX and cephalexin

28. Secondary Treatment of Cellulitis • Elevation of affected leg • Compression stockings • Treat underlying tineapedis, eczema, trauma • Keep skin well hydrated

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

30. Abscess

31. Abscess • ALWAYS, ALWAYS • Incision and drainage

32. Drainable Abscess <3cm • Incision and drainage • No blood cultures • No aspirate culture • NO ANTIBIOTICS

33. Abscess • CBC with diff • BMP • Blood cultures • Culture exudate

34. Abscess –When to Add Antibiotics • Drainable abscess >3cm • Undrainable • 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

35. Abscess Antibiotic Coverage • MRSA coverage • Antibiotic: • Vancomycin

36. Abscess • Deescalation: • Trimethoprim/sulfamethoxazole + cephalexin • Beta lactam anaphylaxis – clindamycin • Sulfa allergy – tetracycline or doxycycline • If sulfa and beta lactam allergies - linezolid • Treatment duration: • Usually 5 days of treatment – 10 maximum

37. Animal Bites

38. 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)

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

40. Human Bites

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

42. Human Bites • Deescalation: • 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

43. Surgical Site Infection

44. 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

45. 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 24-48 hours or for 3 days after acute inflammation resolves

46. Neutropenia and SSTI’s

47. 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 72-96 hours)  

48. 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 PLUS • Vancomycin • Linezolid (restricted to ID) • Daptomycin (restricted to ID) • (discontinue if culture negative after 72-96 hours)

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

50. 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