Treatment of Cellulitis

Diagnosis and Assessment

Cellulitis is an acute bacterial infection of the dermis and subcutaneous tissue that most commonly affects the lower extremities, presenting with local signs of inflammation including warmth, erythema, pain, and lymphangitis 3
Cultures of blood or cutaneous aspirates, biopsies, or swabs are not routinely recommended for typical cases 1, 4
Blood cultures should be obtained in patients with malignancy on chemotherapy, neutropenia, severe cell-mediated immunodeficiency, immersion injuries, and animal bites 1, 5
Carefully examine interdigital toe spaces in lower extremity cellulitis, as treating fissuring, scaling, or maceration may reduce recurrent infection 1, 4

The Infectious Diseases Society of America recommends first-line therapy with an antimicrobial agent active against streptococci for mild cellulitis 1, 2
The American College of Physicians suggests a treatment duration of 5 days, extending if no improvement is seen 1, 2
Outpatient therapy is recommended for patients without systemic signs of infection, altered mental status, or hemodynamic instability 1, 4
For moderate cellulitis, systemic antibiotics with coverage against streptococci and possibly MSSA are recommended 1, 5
Hospitalization should be considered for patients with concerns for deeper infection or poor adherence to therapy 1, 4

Elevation of the affected area to promote gravity drainage of edema and inflammatory substances is recommended 1, 2
Treatment of predisposing factors such as edema, tinea pedis, or underlying cutaneous disorders is essential 1, 2
Systemic corticosteroids could be considered in non-diabetic adult patients 1, 2

Search for local causes such as pilonidal cyst, hidradenitis suppurativa, or foreign material 6
Drain and culture recurrent abscesses early in the course of infection 6
Treat with a 5-10 day course of antibiotics active against the isolated pathogen 6
Consider a 5-day decolonization regimen for recurrent S. aureus infection, including intranasal mupirocin, daily chlorhexidine washes, and daily decontamination of personal items 5, 6
Identify and treat predisposing conditions such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 1
Consider prophylactic antibiotics in patients with 3-4 episodes per year despite treatment of predisposing factors 1

Hospitalization criteria include concern for deeper or necrotizing infection, poor adherence to therapy, severe immunocompromise, or failing outpatient treatment 1, 4