Uninfected

Lack of purulent drainage or inflammation

Cleanse wound

None

Mild

Cellulitis extending less than 2 cm from the wound and at least two of the following: erythema, induration, pain, purulence, tenderness, or warmth; limited to skin or superficial tissues; no evidence of systemic illness

Abscess without surrounding cellulitis: incision and drainage, destruction of loculations, dry dressing

Superficial infections (e.g., impetigo, abrasions, lacerations): topical mupirocin (Bactroban); bacitracin and neomycin less effective

Deeper infections: oral penicillin, first-generation cephalosporin, macrolide, or clindamycin

Topical mupirocin, oral trimethoprim/sulfamethoxazole, or oral tetracycline for MRSA

Moderate

At least one of the following: cellulitis extending 2 cm or more from wound; deep tissue abscess; gangrene; involvement of fascia; lymphangitis; evidence of muscle, tendon, joint, or bone involvement

Cellulitis: five-day course of penicillinase-resistant penicillin or first-generation cephalosporin; clindamycin or erythromycin for patients allergic to penicillin

Bite wounds: five- to 10-day course of amoxicillin/clavulanate (Augmentin); doxycycline or trimethoprim/sulfamethoxazole, or fluoroquinolone plus clindamycin for patients allergic to penicillin

Trimethoprim/sulfamethoxazole for MRSA; patients who are immunocompromised or at risk of noncompliance may require parenteral antibiotics

Severe

Acidosis, fever, hyperglycemia, hypotension, leukocytosis, mental status changes, tachycardia, vomiting

In most cases, hospitalization and initial treatment with parenteral antibiotics

Cellulitis: penicillinase-resistant penicillin, first-generation cephalosporin, clindamycin, or vancomycin

Bite wounds: ampicillin/sulbactam (Unasyn), ertapenem (Invanz), or doxycycline

Linezolid (Zyvox), daptomycin (Cubicin), or vancomycin for cellulitis with MRSA; ampicillin/sulbactam or cefoxitin for clenched-fist bite wounds

Progressive infection despite empiric therapy

Spreading of infection, new symptoms (e.g., fever, metabolic instability)

Treatment should be guided by results of Gram staining and cultures, along with drug sensitivities

Vancomycin, linezolid, or daptomycin for MRSA; consider switching to oral trimethoprim/sulfamethoxazole if wound improves