Skin & Soft Tissue Infections (SSTI) Skin & Soft Tissue Infections 2007 Abscess Cellulitis Bradley W Frazee, MD, FACEP Dept of Emergency Medicine Alameda County Medical Center - Highland Hospital Associate Clinical Professor of Medicine UCSF Necrotizing soft tissue infections (NSTI) Skin & Soft Tissue Infections (SSTI) SSTIs diagnostic approach: first look for pus! Community acquired-mrsa (CA-MRSA) (Abscess) Necrotizing soft tissue infections (NSTI) (Cellulitis) Redness, warmth, tenderness fluctuance or positive bedside ultrasound + Abscess* *Surgical diseases Cellulitis or NSTI* SSTIs Utility of ED ultrasound Diagnosis: unsuspected pus Procedural assistance: localize pus pocket for I&D Deltoid abscess -longitudinal view Contralateral normal shoulder Deltoid abscess -transverse view 1
Ultrasound appearance of cellulitis Isoechoic abscess w/ posterior acoustic enhancement Forearm cellulitis Normal Case #1 the old spider bite 40 y/o woman c/o a spider bite on leg. Onset 3 d/a. Hx same 1 mo/a. Notes husband had similar bite No PMH or Meds No IDU Afebrile. Community-associated MRSA (CA-MRSA) skin and soft tissue infections?!!??! Spontaneous furuncle 2
The story of CA-MRSA Hospital-associated MRSA (HA-MRSA) present since 60 s Multiresistant, SCCmec I-III Pts presenting from community with HA-MRSA infections had risk factors (recent hospitalization, SNF, HD ) CA-MRSA mid 1990 s Community onset MRSA infection - no risk factors Children in U.S. (pneumonia deaths); Native Americans; Australia; France Explosion of skin & soft tissue infections CA-MRSA Distinct genotype SCCmec IV Panton-Valentine Leukocidin (PVL) Distinct phenotype Antibiotic susceptibility: TMP/SMX, clinda, doxy Pathogenicity Spreads within communities outbreaks of skin & soft tissue infections Native American communities Prison inmates Sports teams CA-MRSA Prospective ED study Oakland, CA 2003-2004 Urban, county population 137 adult ED pts w/ skin and soft tissue infections Cultures of infection site & nares (colonization) Risk factor analysis Antibiogram and genotyping CA-MRSA Oakland ED study N=137 Young (<60) 18% homeless 27% IDU Frazee et al. Annals Emerg Med. 2005 CA-MRSA Oakland ED study culture results CA-MRSA Oakland ED study antibiograms USA 300 Nares culture N=137 Negative 97 MRSA 28 (20%) MSSA 12 Infection Site Cultures N=119 Other 14 Negative 26 MSSA 18 MRSA 61 (51%) Antibiotic Oxacillin Erythromycin Levofloxacin Tetracycline Clindamycin MSSA (N=30) 57.7 96.6 96.6 93.3 MRSA (N=89) 0.0 3.6 56.8 85.7 92.0 TMP-SMX Vancomycin Inducible clindamycin resistance (+ D-test) 3
CA-MRSA ED study genotyping of MRSA isolates 99% possessed SCCmec IV allele (marker of CA-MRSA) 87% were a single clone, USA 300 Not reported in California prior to 2000 Linked to MRSA in California prisons, sports team outbreaks Now predominant clone across USA 94% PVL + Instrumental in spontaneous furunculosis (?) Associated w/ necrotizing CA-MRSA pneumonia Multicenter National Study of SSTIs EMERGEncy ID NET OHSU OV-UCLA Maricopa UNM Hennepin UMissouri Charity Grady Bellevue Temple Carolinas Prevalence of MRSA across US 422 ED Patients with SSTI (August, 2004) 7/13 (54%) 24/47 (51%) MSSA 17% 59% 26/42 (62%) 24/47 (51%) 11/28 (39%) 43/58(74%) 23/32 (72%) 46/69 (67%) 4/20 (20%) 32/58 (55%) 17/25 (68%) Overall rise in ED visits for SSTI attributable to CA-MRSA? There has been a dramatic rise in the occurrence of S. aureus infections in general and CA-MRSA in particular Epidemic CA-MRSA disease has been reported in most, but not all, U.S. cities and from some rural areas. ED visits for SSTI 90 80 70 60 50 40 30 20 10 0 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Daum. NEJM 2007 NHMCS preliminary data CA-MRSA risk factors & epidemiology CA-MRSA: antimicrobial options Risk factor data inconsistent: prior CA-MRSA infection (or close contact) Risk groups Prison inmates Contact sport teams HIV-positive American Indian Fomites (dressings, surfaces) Trimethoprim / Sulfamethoxazole (po, IV?) Clindamycin (po or IV) Doxycycline (po) Vancomycin (IV) Linezolid (po or IV) Daptomycin (IV) Dalbavancin (IV q week; not yet available) Rifampin (po) Mupirocin (topical) STOP are antibiotics really necessary? 4
Skin & soft tissue infection treatment algorithm (in setting of prevalence community-acquired MRSA) [2/05 version] Abscess incision & drainage Cellulitis Impetigo Must cover GAS* Keflex +/- TMP/SMX * GAS = Group A strep. Uncomplicated abscess Surgical treatment Strongly consider no Abx If Abx, cover MRSA Doxy or TMP/SMX alone TMP/SMX + keflex or Clindamycin alone Complicated abscess (significant surrounding cellulitis) Infected wound, foot ulcer, etc Immunocompromised host Consider surgical treatment Cover CA-MRSA & GAS po IV Clinda + vanco or Zosyn** + vanco ** if Gram neg. pathogen suspected Abscess I & D options for anesthesia and sedation Local Ring Block Local - bupivicaine ring block Regional anaesthesia Nitro-nox Conscious sedation - fentanyl + midazolam Short acting deep sedation in ED Methohexitol (+ fentanyl) Propofol (+ fentanyl) General anesthesia in OR How do you manage this thing? 5
Abscess post I&D antibiotics CA-MRSA uncomplicated abscess: are antibiotics needed? Literature is scant and non-uniform Uncomplicated abscess 3 prospective randomized trials: all 3 found no benefit to antibiotics NO NO NO surrounding cellulitis often invoked Rutherford. Lancet 1970 Llera. Ann EM 1985 Rajendran. Antimicrob Agents Chemother 2007 Nankin. Ann EM 2007 Maybe Yes CA-MRSA decolonization Other types of CA-MRSA infections: pyomyositis History of multiple furuncles Multiple cases in single household Nasal mupirocin Chlorhexidine (Hibicleanse) washes - axilla and groin Rifampin + TMP/SMX Spontaneous abscess of large muscles (e.g. thigh) Risk factors: diabetes & AIDS Formerly rare in nontropical countries Reports increasing adults and children Panaraj. CID 2006 Ruiz. NEJM 2005 6
Other types of CA-MRSA infections: necrotizing fasciitis 14 adults, Harbor-UCLA 6 IDU 12 monomicrobial for CA-MRSA All USA 300, PVL+ 0% mortality 1 case report of CA-MRSA nec fasc in a 5 d/o infant Miller. NEJM 2005 Dehority. Pediatr Infect Dis J 2006 Other types of CA-MRSA infections: septic arthritis (SA) & osteomyelitis (OM) Texas Children s Hospital 2001-2003, 193 invasive community acquired S. aureus infections Overall: 117 (61%) were CA-MRSA OM: 54 / 82 (66%) SA: 9 / 19 (47%) Arnold. J Ped Ortho 2006 Kaplan. CID 2005 Referral children s hospital in Tennessee, 2000-2004, orthopedic service, osteoarticular infections OM (n=89) SA (n=36) Both (n=33) MRSA 23 (50%) 7 (19%) 17 (51%) Other 20 12 10 Unknown 46 17 6 Other types of CA-MRSA infections: necrotizing pneumonia First cases of CA-MRSA infection in US, mid 1990 s, were fatal pneumonia in children Rare overall, but numerous reports in children and adults In setting influenza-like illness Necrotizing = cavitation and hemoptysis Leukopenia and sepsis syndrome, mortality Empiric vanco or linezolid for severe CAP during flu season? Francis. Clin Infect Dis 2005 Frazee. Ann Int Med 2005 7