SHM's Clinical Quick Talks-Skin and Soft Tissue Infections

Pdf Summary
This summary review by Dr. Halle Field addresses skin and soft tissue infections (SSTIs), focusing on their diagnosis and treatment, particularly cellulitis (a type of nonpurulent SSTI). SSTIs are categorized into nonpurulent (cellulitis and necrotizing infections), purulent (abscesses, carbuncles, furuncles), and necrotizing infections (involving fascia/muscle with significant mortality risk).<br /><br />Key causative organisms vary by type: nonpurulent often involves group A streptococci and MSSA; purulent usually caused by Staphylococcus aureus including MRSA; necrotizing infections can be polymicrobial involving GAS, Staph aureus, anaerobes, and Gram-negative rods.<br /><br />Diagnosis for nonpurulent SSTIs is clinical, typically affecting deeper dermis and subcutaneous tissues, commonly on legs, with wound cultures not useful. Purulent SSTIs require incision and drainage (I&D) for culture and tailored antibiotics. Necrotizing infections demand urgent surgical evaluation, with clinical signs including severe pain disproportionate to examination, skin necrosis, and presence of gas or bullae.<br /><br />Differential diagnosis is important because cellulitis is often overdiagnosed; common mimics include stasis dermatitis (usually bilateral, chronic), contact dermatitis (pruritic), herpes zoster (dermatomal vesicles), and gout (painful joint erythema).<br /><br />Treatment depends on infection type and severity: <br />- Nonpurulent SSTIs without systemic symptoms are treated outpatient with oral antibiotics targeting streptococci and MSSA; hospitalized patients with systemic symptoms receive IV beta-lactams or vancomycin if allergic. Immunocompromised patients require broader IV coverage. Duration is typically 5 days, adjusted by clinical response.<br />- Purulent SSTIs require I&D plus empiric antibiotics targeting MRSA; antibiotics tailored by culture. <br />- Necrotizing infections need urgent surgery plus broad-spectrum IV antibiotics covering MRSA, gram negatives, anaerobes, and clindamycin for antitoxin effects.<br /><br />Clinical pearls emphasize no wound cultures for nonpurulent cellulitis, necessity of I&D for purulent infections, and urgent surgical intervention for necrotizing infections. The review highlights consultation of local antibiograms and infectious disease stewardship for appropriate antibiotic use. <br /><br />References include updated Infectious Diseases Society of America guidelines and recent clinical reviews on SSTIs and cellulitis.
Asset Subtitle
Halle Field
Keywords
skin and soft tissue infections
SSTIs
cellulitis
nonpurulent infections
purulent infections
necrotizing infections
group A streptococci
Staphylococcus aureus
MRSA
incision and drainage