What is the recommended treatment for cellulitis in older adults?

Recommended Treatment for Cellulitis in Older Adults

For typical cellulitis in older adults, a 5-day course of antibiotics active against streptococci, such as cephalexin 500 mg four times daily, is the recommended first-line treatment, with extension if the infection has not improved within this time period. 1, 2

First-Line Antibiotic Selection

• For non-purulent, uncomplicated cellulitis, oral antibiotics active against streptococci are recommended, including:

  • Penicillin
  • Amoxicillin
  • Amoxicillin-clavulanate
  • Dicloxacillin
  • Cephalexin (500 mg four times daily)
  • Clindamycin 3, 1, 2

• MRSA is an unusual cause of typical cellulitis, and β-lactam monotherapy (like cephalexin) is appropriate in the absence of abscess, ulcer, or purulent drainage 2, 4

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course for uncomplicated cellulitis if clinical improvement has occurred by day 5 3, 2
• Treatment should be extended if the infection has not improved within the initial 5-day period 1, 2

Special Considerations for Older Adults

• Consider potential drug interactions and comorbidities common in older adults when selecting antibiotics 5
• Elevation of the affected area is particularly important in older adults to promote gravity drainage of edema and inflammatory substances 3, 2
• Identify and treat predisposing conditions that are common in older adults, such as:
  • Venous insufficiency
  • Lymphedema
  • Tinea pedis or other toe web abnormalities
  • Prior trauma to the area 3, 2

When to Consider MRSA Coverage

• Consider adding MRSA coverage only in specific situations:

  • Cellulitis associated with penetrating trauma
  • Evidence of MRSA infection elsewhere
  • Purulent drainage
  • History of injection drug use 3, 2

• Options for MRSA coverage include:

  • Clindamycin alone
  • Combination of SMX-TMP or doxycycline with a β-lactam 3

Adjunctive Therapy

• Systemic corticosteroids (e.g., prednisone 40 mg daily for 7 days) could be considered in non-diabetic older adults to reduce inflammation and hasten resolution 3, 1, 2
• NSAIDs may also help hasten resolution of cellulitis-related inflammation when added to antibiotic therapy 6

Hospitalization Criteria

• Consider hospitalization for older adults with:
  • Severe infections with systemic inflammatory response syndrome
  • Altered mental status
  • Hemodynamic instability
  • Concern for deeper or necrotizing infection
  • Poor adherence to therapy
  • Immunocompromise
  • Failure of outpatient treatment 1, 2

Prevention of Recurrence

• For older adults with frequent episodes of cellulitis, consider prophylactic antibiotics such as:

  • Oral penicillin
  • Erythromycin
  • Intramuscular benzathine penicillin 1

• Address underlying conditions that predispose to recurrence:

  • Treat tinea pedis
  • Manage venous insufficiency and lymphedema
  • Address any skin trauma or breakdown 3, 5

Common Pitfalls to Avoid

• Don't extend treatment unnecessarily beyond 5 days if clinical improvement has occurred 2
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 2, 4
• Don't forget to examine interdigital toe spaces in lower-extremity cellulitis, as treating fissuring or maceration may reduce recurrence 2
• Don't overlook the importance of elevating the affected area, especially in older adults with venous insufficiency or lymphedema 3, 2

Emerging Evidence

• A recent pilot study suggests that high-dose cephalexin (1000 mg four times daily) may result in fewer treatment failures compared to standard-dose (500 mg four times daily), though with a higher proportion of minor adverse effects 7