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

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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Abscess

Abscess ALWAYS, ALWAYS Incision and drainage Culture aspirate

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

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

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

Animal Bites

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)

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

Human Bites

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***

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

Surgical Site Infection

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

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

Neutropenia and SSTI’s

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)  

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 72-96 hours)

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

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

Diabetic Foot Ulcers

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

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

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

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

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

References Gunderson CG. Cellulitis: Definition, etiology, and clinical features. Am J Med2011;124:1113-1122.  Jenkins TC, et al. Decreased antibiotic utilization after implementation of a guideline for inpatient cellulitis and cutaneous abscess.  Arch Intern Med. 2011;171(12):1072-1079. 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;350:904-912.  IDSA GUIDELINES: Lipsky BA, et al. Diagnosis and treatment of foot infections. Clin Infect Dis  2004;39:885-910. 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;41:1373-1406.