What are the guidelines for managing cellulitis in a patient?

From the Guidelines

Cellulitis should be treated with a 5- to 6-day course of antibiotics active against streptococci, particularly for patients able to self-monitor and who have close follow-up with primary care. The most recent and highest quality study, published in 2021 in the Annals of Internal Medicine 1, recommends this approach for nonpurulent cellulitis. This guideline is based on the best practice advice from the American College of Physicians and is consistent with other recent studies, such as the 2014 update by the Infectious Diseases Society of America 1.

Key Considerations

• The choice of antibiotic should target the most common causative organisms, primarily beta-hemolytic streptococci and Staphylococcus aureus.
• For mild, uncomplicated cellulitis in patients without methicillin-resistant S. aureus (MRSA) risk factors, oral antibiotics such as cephalexin or penicillin are recommended.
• If MRSA is suspected, additional coverage with trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline may be necessary.
• Patients should be educated to elevate the affected area, apply warm compresses, and monitor for signs of worsening infection, such as spreading redness, fever, or increasing pain.

Treatment Duration and Supportive Care

• The recommended duration of antimicrobial therapy is 5-6 days, but treatment should be extended if the infection has not improved within this time period.
• Adequate hydration and pain management with acetaminophen or ibuprofen are also important supportive measures.
• Elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are recommended to prevent recurrence and promote healing.

From the Research

Guidelines for Managing Cellulitis

• The diagnosis of cellulitis is based primarily on history and physical examination 2
• Treatment of primary and recurrent cellulitis should initially cover Streptococcus and methicillin-sensitive S. aureus, with expansion for methicillin-resistant S. aureus (MRSA) in cases of cellulitis associated with specific risk factors 2
• Five days of treatment is sufficient with extension if symptoms are not improved 2
• Addressing predisposing factors can minimize risk of recurrence 2, 3
• Uncomplicated cellulitis can be managed in the outpatient setting with oral antibiotics 3
• Imaging often is not required but can be helpful 3
• For patients with frequent recurrences despite management of underlying conditions, antimicrobial prophylaxis can be effective 3

Antibiotic Treatment

• The majority of non-purulent, uncomplicated cases of cellulitis are caused by β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus, and appropriate targeted coverage of this pathogen with oral antibiotics such as penicillin, amoxicillin, and cephalexin is sufficient 4
• Even with rising rates of community-acquired methicillin-resistant Staphylococcus aureus, coverage for non-purulent cellulitis is generally not recommended 4
• Antibiotics with activity against community-associated MRSA, such as trimethoprim-sulfamethoxazole and clindamycin, are preferred empiric therapy for outpatients with cellulitis in the community-associated MRSA-prevalent setting 5

Route of Antibiotic Administration

• A systematic review and meta-analysis is currently underway to compare the efficacy of oral versus intravenous antibiotic administration for cellulitis infections 6
• The primary objective of this review is to provide clinicians with evidence-based guidelines for treatment 6
• The primary outcome for this review is the duration of infection resolution, and secondary outcomes such as incidence of sepsis, mortality, hospital admission, and Clostridium difficile infection 6