Can an additional course of antibiotics be given if cellulitis is not fully resolved?

Additional Antibiotic Course for Unresolved Cellulitis

Treatment should be extended if cellulitis has not improved after the initial 5-day course of antibiotics. 1

Assessment of Treatment Response

• Evaluate for signs of improvement after the initial antibiotic course, looking for:

  • Reduction in erythema, warmth, and tenderness 1
  • Decreased swelling and induration 1
  • Resolution of fever 1
  • Overall improvement in cellulitis severity 2

• If the infection has not improved within the initial 5-day treatment period, extending antibiotic therapy is strongly recommended 1

Antibiotic Selection for Extended Treatment

• Continue with the same antibiotic if:

  • The initial agent was appropriate for the suspected pathogen 1
  • There is partial improvement but complete resolution has not occurred 1

• For non-purulent cellulitis (most common):

  • Continue antibiotics active against streptococci, which are the predominant pathogens 1, 3
  • Options include penicillins, cephalosporins, or clindamycin 1

• For cellulitis with specific risk factors for MRSA:

  • Continue coverage for both MRSA and streptococci if the patient has:
    • History of penetrating trauma 1
    • Evidence of MRSA infection elsewhere 1
    • MRSA nasal colonization 1
    • History of injection drug use 1
    • Systemic inflammatory response syndrome (SIRS) 1

Duration of Extended Treatment

• The total duration of therapy should be guided by clinical response 1

• Continue antibiotics until there is resolution of:

  • Warmth and tenderness 4
  • Significant improvement in erythema and edema 4

• Most cases that require extended treatment will resolve with a total of 10-14 days of antibiotics 4

Special Considerations

• For patients with severe cellulitis or who are immunocompromised:

  • Broader spectrum coverage may be needed 1
  • Longer duration of therapy is often required 1

• For patients with recurrent cellulitis:

  • Address predisposing factors such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 1
  • Examine interdigital toe spaces for fissuring, scaling, or maceration that may harbor pathogens 1

• Consider hospitalization if:

  • Outpatient treatment is failing 1
  • There are concerns for deeper or necrotizing infection 1
  • The patient is severely immunocompromised 1

Potential Pitfalls

• Failure to improve with appropriate antibiotics should prompt consideration of:

  • Resistant organisms 3
  • Secondary conditions mimicking cellulitis 3
  • Underlying complicating conditions (immunosuppression, chronic liver or kidney disease) 3
  • Presence of undrained purulent collections requiring drainage 1

• Avoid unnecessarily prolonged antibiotic courses when possible, as this contributes to antimicrobial resistance 4

• Be aware that shorter courses (6 days) may be associated with higher relapse rates by day 90 compared to longer courses (12 days) in severe cellulitis 2