What is the initial management for purulent incision cellulitis?

Initial Management of Purulent Incision Cellulitis

For purulent incision cellulitis, incision and drainage is the primary treatment, with empirical antibiotic therapy targeting CA-MRSA recommended for 5-10 days, using agents such as clindamycin, trimethoprim-sulfamethoxazole (TMP-SMX), or doxycycline. 1

Immediate Surgical Intervention

• Incision and drainage is the cornerstone of treatment for any purulent collection and must be performed before or concurrent with antibiotic initiation 1
• For surgical site infections with purulent drainage, suture removal plus incision and drainage should be performed immediately 1
• Simple drainage alone may be adequate for uncomplicated abscesses, but additional antibiotic therapy is warranted when specific risk factors are present 1

Indications for Adjunctive Antibiotic Therapy

Antibiotics are mandatory when purulent incision cellulitis is associated with:

• Severe or extensive disease involving multiple sites or rapid progression 1
• Associated cellulitis with erythema and induration extending >5 cm from the wound edge 1
• Signs and symptoms of systemic illness (fever, tachycardia, hypotension) 1
• Associated comorbidities or immunosuppression 1
• Extremes of age 1
• Abscess in difficult-to-drain areas (face, hand, genitalia) 1
• Associated septic phlebitis 1
• Lack of response to incision and drainage alone 1

Empirical Antibiotic Selection

For outpatient management of purulent incision cellulitis, empirical CA-MRSA coverage is recommended pending culture results, as empirical therapy for β-hemolytic streptococci is likely unnecessary in this setting. 1

Oral Antibiotic Options (Outpatient):

• Clindamycin 300-450 mg orally every 6 hours (covers both streptococci and MRSA as monotherapy) 1
• TMP-SMX 1-2 double-strength tablets twice daily (MRSA coverage only; must add β-lactam if streptococcal coverage needed) 1
• Doxycycline 100 mg orally twice daily (MRSA coverage only; must add β-lactam if streptococcal coverage needed) 1
• Linezolid 600 mg orally twice daily (covers both streptococci and MRSA but expensive; reserve for complicated cases) 1

Intravenous Options (Hospitalized Patients):

For complicated surgical site infections requiring hospitalization with systemic signs:

• Vancomycin 15-20 mg/kg IV every 8-12 hours (first-line, A-I evidence) 1, 2
• Linezolid 600 mg IV twice daily (A-I evidence) 1
• Daptomycin 4 mg/kg IV once daily (A-I evidence) 1
• Clindamycin 600 mg IV every 8 hours (if local MRSA resistance <10%, A-III evidence) 1

Treatment Duration

• Treat for 5-10 days, individualized based on clinical response 1
• Five days is sufficient if clinical improvement occurs; extend only if symptoms have not improved within this timeframe 1, 3
• For complicated surgical site infections requiring hospitalization, 7-14 days may be necessary 1

Surgical Site-Specific Considerations

For surgical wounds on trunk or extremities away from axilla/perineum:

• Oxacillin or nafcillin 2 g IV every 6 hours 1
• Cefazolin 0.5-1 g IV every 8 hours 1
• Cephalexin 500 mg orally every 6 hours 1
• TMP-SMX 160-800 mg orally every 6 hours 1
• Vancomycin 15 mg/kg IV every 12 hours (if MRSA coverage needed) 1, 2

For surgical wounds in axilla or perineum (polymicrobial coverage needed):

• Metronidazole 500 mg IV every 8 hours PLUS ciprofloxacin 400 mg IV every 12 hours or levofloxacin 750 mg IV every 24 hours or ceftriaxone 1 g IV every 24 hours 1, 4

Critical Pitfalls to Avoid

• Do not rely on antibiotics alone without drainage for purulent collections—this represents treatment failure from the outset 1, 5
• Do not use TMP-SMX or doxycycline as monotherapy for purulent cellulitis if streptococcal coverage is needed, as their activity against β-hemolytic streptococci is unreliable 1
• Do not use rifampin as single agent or adjunctive therapy for skin and soft tissue infections 1
• Do not delay surgical consultation if signs of systemic toxicity, rapid progression, or necrotizing infection are present 1

Adjunctive Measures

• Elevate the affected area to promote drainage and hasten improvement 1, 3
• Obtain wound cultures at time of drainage to guide definitive therapy 6
• Assess for and treat predisposing conditions (edema, venous insufficiency, diabetes) 1, 3
• Reassess within 24-48 hours to verify clinical response 3

When to Hospitalize

Admit patients with:

• Systemic inflammatory response syndrome (SIRS) criteria 1, 3
• Hemodynamic instability or altered mental status 1, 3
• Severe immunocompromise or neutropenia 3
• Concern for deeper or necrotizing infection 1, 3
• Failure of outpatient management 1, 3