From the Guidelines
Diagnosis and Treatment of Cellulitis
Cellulitis is a bacterial skin infection that should be treated with oral antibiotics for 5 days, with the option to extend treatment if the infection has not improved within this time period 1.
Typical Cases
For typical cases of cellulitis without systemic signs of infection, an antimicrobial agent active against streptococci is recommended, such as cephalexin 500mg four times daily or dicloxacillin 500mg four times daily 1.
Cases with Systemic Signs of Infection
In cases of cellulitis with systemic signs of infection, systemic antibiotics are indicated, and coverage against methicillin-susceptible S. aureus (MSSA) may be included 1.
MRSA Consideration
For patients with cellulitis associated with penetrating trauma, evidence of MRSA infection elsewhere, nasal colonization with MRSA, injection drug use, or systemic inflammatory response syndrome (SIRS), vancomycin or another antimicrobial effective against both MRSA and streptococci is recommended 1.
Treatment Duration
The recommended duration of antimicrobial therapy is 5 days, but treatment should be extended if the infection has not improved within this time period 1.
Severe Infections
Patients with severe infections or those who are immunocompromised may require intravenous antibiotics, such as cefazolin 1g every 8 hours or vancomycin 1g every 12 hours, and hospitalization for close monitoring and supportive care 1.
Key Points
- Cellulitis is typically treated with oral antibiotics for 5 days
- Antimicrobial agents active against streptococci are recommended for typical cases
- Systemic antibiotics are indicated for cases with systemic signs of infection
- Vancomycin or other antimicrobials effective against MRSA and streptococci may be recommended in certain cases
- Treatment duration may be extended if the infection has not improved within 5 days
- Severe infections or immunocompromised patients may require intravenous antibiotics and hospitalization.
From the Research
Diagnosis of Cellulitis
- Cellulitis is typically diagnosed based on clinical presentation, including symptoms such as fever, erythema, swelling, and tenderness 2.
- Soft tissue ultrasound may be performed to exclude abscess 2.
- Laboratory tests, such as C-reactive protein, may be used to assess the severity of the infection 3.
Treatment of Cellulitis
- For uncomplicated cellulitis, antimicrobial regimens such as cephalexin alone or in combination with trimethoprim-sulfamethoxazole may be effective 2.
- For methicillin-resistant Staphylococcus aureus (MRSA) infections, alternative therapies such as linezolid, daptomycin, or vancomycin alternatives (e.g. ceftaroline, ceftobribole, dalbavancin, oritavancin, and tedizolid) may be considered 4.
- Empiric treatment with oral antibiotics (e.g. trimethoprim-sulfamethoxazole, clindamycin, doxycycline/minocycline, linezolid) may be appropriate for moderate skin and soft tissue infections in the outpatient setting 4.
- Intravenous antibiotic therapy may be necessary for more severe or invasive infections, with follow-on oral antibiotics used to complete the treatment course 3.
- The choice of treatment should take into account the safety profile of the antibiotic, as well as the potential for adverse events 5.
Factors Influencing Treatment Duration
- Clinical factors such as age, peak C-reactive protein, and frequency of medical assessments during outpatient parenteral antimicrobial therapy (OPAT) may influence the duration of intravenous therapy 3.
- Operational factors, such as the day of the week, may also impact the timing of intravenous to oral conversion 3.
- Senior clinicians may be more likely to prescribe shorter courses of follow-on oral antibiotics 3.