What are the management options for cellulitis?

Management of Cellulitis

The first-line treatment for cellulitis should include an antibiotic active against streptococci, with oral therapy sufficient for most cases of uncomplicated cellulitis, and a 5-day course is as effective as a 10-day course if clinical improvement occurs by day 5. 1

Antibiotic Selection

Oral Therapy for Mild to Moderate Cellulitis

• For typical uncomplicated cellulitis, suitable oral antibiotics include:
  • Penicillin or amoxicillin (if streptococcal infection is strongly suspected) 1
  • Dicloxacillin, cephalexin, or amoxicillin-clavulanate (for broader coverage including S. aureus) 1, 2
  • Clindamycin (particularly useful after recent beta-lactam therapy to avoid resistance development) 3

Parenteral Therapy for Severe Cases

• For severely ill patients or those unable to tolerate oral medications, recommended options include:
  • Nafcillin (penicillinase-resistant penicillin) 1
  • Cefazolin (first-generation cephalosporin) 1
  • Clindamycin or vancomycin (for patients with severe penicillin allergies) 1

MRSA Considerations

When to Consider MRSA Coverage

• MRSA is an unusual cause of typical cellulitis, but coverage should be considered in specific situations 1:
  • Penetrating trauma, especially from illicit drug use 1, 2
  • Presence of purulent drainage 1, 2
  • Concurrent evidence of MRSA infection elsewhere 1, 2
  • Systemic inflammatory response syndrome 2
  • Lack of response to beta-lactam antibiotics 2

MRSA Treatment Options

• For outpatient MRSA treatment:

  • Trimethoprim-sulfamethoxazole (consider adding a beta-lactam for streptococcal coverage) 1, 2
  • Clindamycin 1, 2
  • Doxycycline (with a beta-lactam for streptococcal coverage) 1

• For inpatient MRSA treatment:

  • Vancomycin 1, 2
  • Linezolid 1, 2
  • Daptomycin 1, 2
  • Telavancin 1, 2

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course if clinical improvement has occurred by day 5 1, 4
• Treatment should be extended if the infection has not improved within this time period 2, 5

Adjunctive Measures

Anti-inflammatory Therapy

• Systemic corticosteroids (e.g., prednisone 40 mg daily for 7 days) may be considered in non-diabetic adult patients with cellulitis to hasten resolution 1
• In one study, patients receiving prednisolone showed shortened healing time, treatment time with IV antibiotics, and hospital stay by 1 day 1
• NSAIDs may also help hasten resolution of inflammation when added to antibiotic therapy 6

Supportive Care

• Elevation of the affected area is crucial and often neglected; it promotes gravity drainage of edema and inflammatory substances 1, 3
• Treat underlying predisposing conditions such as:
  • Tinea pedis 1
  • Venous eczema ("stasis dermatitis") 1
  • Trauma or skin lesions 1, 7

Management of Recurrent Cellulitis

• Each attack of cellulitis causes lymphatic inflammation and possibly permanent damage 1
• Measures to reduce recurrences include:
  • Treating interdigital maceration 1
  • Keeping skin well hydrated with emollients 1
  • Reducing underlying edema through elevation, compression stockings, or diuretics if appropriate 1
• For frequent infections despite these measures, prophylactic antibiotics may be considered:
  • Monthly intramuscular benzathine penicillin injections (1.2 MU in adults) 1
  • Oral therapy with twice-daily doses of either 250 mg of erythromycin or 1 g of penicillin V 1

Common Pitfalls and Caveats

• Blood cultures and skin biopsies are unnecessary for typical cases of cellulitis 1
• MRSA is an unusual cause of typical cellulitis, and treatment for this organism is usually unnecessary unless specific risk factors are present 1, 4
• Cutaneous inflammation may worsen after initiating therapy due to sudden destruction of pathogens releasing enzymes that increase local inflammation 1
• Patients slow to respond may have deeper infection or underlying conditions such as diabetes, chronic venous insufficiency, or lymphedema 1, 4
• Ongoing local symptoms and signs after completion of antibiotic treatment do not necessarily indicate treatment failure or warrant extension of antibiotics 5