Optimal Management of Cellulitis

Evaluation and Diagnosis

The Infectious Diseases Society of America recommends that cellulitis is an infection of the deep dermis and subcutaneous tissue that presents with expanding erythema, heat, sensitivity, and swelling in a patient 1
The diagnosis is primarily clinical; blood cultures, tissue aspirates, or skin biopsies are generally not necessary for typical cases of cellulitis in a patient 1
Blood cultures should be obtained in patients with malignancy, severe systemic characteristics (such as high fever and hypotension), and unusual predisposing factors 1

For typical cases without severe systemic signs, the Infectious Diseases Society of America recommends antibiotics active against streptococci, such as penicillin, amoxicillin, amoxicillin-clavulanate, dicloxacillin, cephalexin, or clindamycin in a patient 1, 3
The recommended duration is 5 days, with extension if the infection has not improved in this period in a patient 1
For severe infections with systemic signs (fever >38.5°C, heart rate >110 beats/minute, or white blood cell count >12,000/μL), the Infectious Diseases Society of America recommends intravenous antibiotic therapy in a patient 1, 4
Options for intravenous therapy include:

The Infectious Diseases Society of America recommends hospitalization for patients with severe infections, signs of SIRS (systemic inflammatory response syndrome), altered mental status, hemodynamic instability, or suspicion of deeper or necrotizing infection in a patient 1, 3

MRSA is an unusual cause of typical cellulitis; however, coverage for MRSA may be prudent in cellulitis associated with traumatic injury, especially with illicit drug use, purulent drainage, or concurrent evidence of MRSA infection elsewhere in a patient 1, 4
For patients with liver failure, ceftriaxone is recommended as first-line due to its efficacy against common pathogens and reduced hepatic metabolism in a patient 5

Elevation of the affected area to promote edema drainage in a patient 3
Identification and treatment of predisposing factors such as edema, obesity, eczema, venous insufficiency, and interdigital space anomalies in a patient 1, 3

For patients with frequent episodes (3-4 episodes per year), consider prophylactic antibiotics such as penicillin or erythromycin oral twice daily for 4-52 weeks in a patient 1, 3
Injections of penicillin benzathine every 2-4 weeks in a patient 4