Empiric therapy for skin and soft-tissue infections (SSTIs) is usually successful.
β-Lactam antibiotics (penicillins and cephalosporins) and clindamycin are first line options for empiric therapy for mild and moderate nonpurulent SSTIs.
Antibiotic resistance is a growing concern. Culture and sensitivity help to define better management.
Empiric therapy for moderate and severe purulent SSTIs should cover methicillin-resistant Staphylococcus aureus (MRSA).
β-Lactam antibiotics and vancomycin inhibit bacterial cell wall synthesis.
Several antibiotic classes interfere with bacterial protein synthesis by binding ribosomal subunits: tetracyclines at 30S; lincosamides (clindamycin), macrolides, streptogramins, and oxazolidinones (linezolid) at 50S.
New agents for SSTIs include ceftaroline, lipoglycopeptides (dalbavancin, oritavancin, and telavancin), and oxazolidinones (tedizolid).
Topical antibiotics may negate the need for systemic antibiotics in the treatment of impetigo; they are unnecessary as postsurgical prophylaxis to prevent wound infection.
Antibiotics are soluble compounds usually produced by organisms that inhibit bacterial growth, and also include synthetic compounds. The majority of skin and soft tissue infections (SSTIs) are caused by Gram-positive organisms, most of which are susceptible to agents with a relatively narrow spectrum of antimicrobial activity. β-Lactams have been the mainstay of therapy for SSTIs.1 Increased use and misuse of antibiotics have led to selection and propagation of resistant bacteria. Community-acquired resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) have increased in recent years and MRSA now accounts for 50% of all SSTIs with significant morbidity, mortality, and health-care cost.2-5 The therapeutic approach should be guided by the type of SSTI (purulent or nonpurulent) and clinical severity (mild, moderate, or severe). Empiric therapy for moderate or severe purulent SSTIs should include coverage for MRSA.6 β-Lactams remain the recommended empiric therapy for mild or moderate nonpurulent SSTIs. The emergence of complicated SSTIs with resistant pathogens, for example, MRSA and vancomycin-resistant Enterococcus (VRE) are even more ominous; such complicated infections involve deeper tissues or occur in patients with underlying disease, and may necessitate surgical intervention.
Most SSTIs respond to antibiotic monotherapy (Table 186-1). Combination therapy may be necessary in severe situations such as necrotizing fasciitis. Increasing pathogen resistance and the relative paucity of new antimicrobials may pose therapeutic challenges for physicians. Understanding the pharmacologic properties of antibiotics ensures judicious use of these agents, and familiarity with antibiotic dosing schedules and adverse events will lead to therapeutic choices that achieve the highest degree of patient compliance.
TABLE 186-1Recommended Therapies ||Download (.pdf) TABLE 186-1 Recommended Therapies
|ORGANISM ||DISEASE ||FIRST-LINE THERAPY ||ALTERNATIVE THERAPY |
|Actinomyces israelii ||Actinomycosis ||Penicillin or amoxicillin ||Doxycycline, clindamycin, erythromycin |
|Bacillus anthracis ||Cutaneous anthrax ||Doxycycline, ciprofloxacin, levofloxacin, or moxifloxacin ||Penicillin or amoxicillin (if sensitive) |
|Bartonella spp. ||Cat-scratch disease, bacillary angiomatosis, Carrion disease, trench fever || |
Aminoglycosides (other Bartonella)
Clarithromycin, rifampin, ciprofloxacin, TMP-SMX
Erythromycin or doxycycline (BA)
|Borrelia burgdorferi ||Lyme disease ||Doxycycline or amoxicillin ||Ceftriaxone, cefuroxime axetil, cefotaxime |
|Borrelia recurrentis ||Relapsing fever ||Doxycycline ||Penicillin, ...|