What is the treatment for abdominal wall cellulitis?

Treatment of Abdominal Wall Cellulitis

For abdominal wall cellulitis, treat with beta-lactam monotherapy (cephalexin 500 mg four times daily, dicloxacillin 250-500 mg every 6 hours, or amoxicillin) for 5 days if clinical improvement occurs, as this approach succeeds in 96% of typical cellulitis cases. 1

Initial Antibiotic Selection

Beta-lactam monotherapy is the standard of care for uncomplicated abdominal wall cellulitis without purulent drainage or MRSA risk factors. 1

Oral Options for Outpatient Management

• Cephalexin 500 mg orally four times daily 1
• Dicloxacillin 250-500 mg orally every 6 hours 1
• Amoxicillin (standard dosing) 1
• Penicillin V 250-500 mg orally four times daily 1

These agents provide excellent coverage against β-hemolytic streptococci and methicillin-sensitive Staphylococcus aureus, which account for the majority of identified pathogens in cellulitis. 2, 3

Intravenous Options for Hospitalized Patients

• Cefazolin 1-2 g IV every 8 hours (preferred IV beta-lactam) 4, 1
• Nafcillin 2 g IV every 6 hours 1
• Oxacillin 2 g IV every 6 hours 1

Treatment Duration

Treat for exactly 5 days if clinical improvement has occurred; extend only if symptoms have not improved within this timeframe. 1, 5 This recommendation is based on high-quality randomized controlled trial evidence demonstrating that 5-day courses achieve 98% clinical resolution with no relapse by 28 days, equivalent to 10-day courses. 5

When to Add MRSA Coverage

Do NOT routinely add MRSA coverage for typical nonpurulent abdominal wall cellulitis, as MRSA is an uncommon cause even in high-prevalence settings. 1, 2

Add MRSA-Active Antibiotics ONLY When These Risk Factors Are Present:

• Penetrating trauma to the abdominal wall 1
• Purulent drainage or exudate 1
• Injection drug use 1
• Known MRSA colonization or prior MRSA infection 1
• Systemic inflammatory response syndrome (SIRS) 1

MRSA-Active Regimens When Indicated:

• Clindamycin 300-450 mg orally every 6 hours (covers both streptococci and MRSA, avoiding need for combination therapy) 1
• Trimethoprim-sulfamethoxazole PLUS a beta-lactam (combination required as TMP-SMX lacks reliable streptococcal coverage) 1
• Doxycycline 100 mg orally twice daily PLUS a beta-lactam (combination required as doxycycline lacks reliable streptococcal coverage) 1

Indications for Hospitalization

Hospitalize patients with abdominal wall cellulitis if any of the following are present: 1, 6

• Systemic inflammatory response syndrome (fever >38°C, tachycardia >90 bpm, tachypnea >24 breaths/min) 1
• Hypotension or hemodynamic instability 1
• Altered mental status or confusion 1
• Severe immunocompromise or neutropenia 1
• Concern for deeper infection or necrotizing fasciitis 1

Severe Infections Requiring Broad-Spectrum Therapy

For abdominal wall cellulitis with signs of systemic toxicity, rapid progression, or suspected necrotizing fasciitis, initiate mandatory broad-spectrum combination therapy immediately. 1

Recommended IV Combination Regimens:

• Vancomycin 15-20 mg/kg IV every 8-12 hours PLUS piperacillin-tazobactam 3.375 g IV every 6 hours 4, 1
• Linezolid 600 mg IV twice daily PLUS piperacillin-tazobactam 1
• Vancomycin PLUS a carbapenem (meropenem 1 g IV every 8 hours) 4, 1
• Vancomycin PLUS ceftriaxone 1-2 g IV every 12-24 hours and metronidazole 500 mg IV every 8-12 hours 4, 1

Critical Warning Signs of Necrotizing Infection

Obtain emergent surgical consultation if any of these features are present: 1

• Severe pain out of proportion to physical examination findings 1
• Skin anesthesia or "wooden-hard" subcutaneous tissues 1
• Rapid progression despite appropriate antibiotics 1
• Gas in tissue (crepitus) 1
• Bullous changes or skin necrosis 1

Adjunctive Measures

Elevation of the affected area promotes gravitational drainage of edema and inflammatory substances, hastening improvement. 1, 6

Treat predisposing conditions to reduce recurrence risk: 1

• Address any surgical site infections or wound complications
• Manage obesity and chronic edema
• Treat any underlying skin conditions (eczema, dermatitis)

Common Pitfalls to Avoid

• Do not reflexively add MRSA coverage simply because the infection involves the abdominal wall—beta-lactam monotherapy succeeds in 96% of typical cases 1
• Do not use doxycycline or TMP-SMX as monotherapy—these agents lack reliable streptococcal coverage and require combination with a beta-lactam 1
• Do not continue ineffective antibiotics beyond 48 hours—progression despite appropriate therapy indicates either resistant organisms or a deeper/different infection requiring reassessment 1
• Do not delay surgical consultation if necrotizing infection is suspected—these infections progress rapidly and require debridement 1