Is Keflex (Cephalexin) appropriate for a 65-year-old male with diabetes presenting with a week-old foot wound showing signs of erythema around the edges?

Management of Diabetic Foot Infection in a 65-Year-Old Male

Cephalexin (Keflex) is an appropriate first-line antibiotic choice for this patient with a diabetic foot wound showing erythema without fluctuance or drainage, as it provides good coverage against the most common pathogens in mild diabetic foot infections. 1

Assessment of Infection Severity

This patient presents with:

• 65-year-old male with diabetes
• Week-old foot wound
• Erythema around the edges (sign of infection)
• No fluctuance or drainage
• No mention of systemic symptoms

Based on the IDSA guidelines, this appears to be a mild diabetic foot infection (DFI), defined by:

• Presence of ≥2 classic signs of inflammation (erythema present)
• Limited to skin and superficial subcutaneous tissue
• No systemic signs of infection 1

Antibiotic Selection

Rationale for Cephalexin (Keflex):

1. For mild DFIs, empiric therapy should target gram-positive cocci, especially staphylococci and streptococci, which are the most common pathogens 1
2. Oral therapy is appropriate for mild infections in patients who can tolerate oral medications 2
3. Cephalexin, a first-generation cephalosporin, provides excellent coverage against the most common causative organisms 1, 2
4. Treatment duration for mild infections is typically 7-10 days 2

Alternative Options:

• Amoxicillin-clavulanate if broader coverage is desired
• Clindamycin if penicillin allergy is present
• Trimethoprim-sulfamethoxazole if MRSA is suspected 1, 2

Important Considerations

When to Broaden Coverage:

• Consider broader coverage if:
  • Patient has had previous antibiotic treatment
  • Chronic wound
  • History of MRSA
  • Immunocompromised state
  • Poor response to initial therapy within 48-72 hours 1, 2

When to Add Pseudomonas Coverage:

• Not indicated in this case unless:
  • Foot frequently exposed to water
  • Previous antibiotic failure
  • Chronic wound 2

When to Add Anaerobic Coverage:

• Not indicated in this case unless:
  • Necrotic tissue present
  • Gangrenous changes
  • Ischemic limb 2

Additional Management

Wound Care:

• Debridement of any necrotic tissue or surrounding callus is essential 1
• Appropriate dressing based on wound characteristics
• Offloading pressure from the wound 1

Monitoring:

• Re-evaluate within 48-72 hours to assess response to therapy 2
• If no improvement after 48-72 hours, consider:
  • Changing antibiotics
  • Obtaining cultures
  • Reassessing for deeper infection or osteomyelitis 1, 2

Red Flags Requiring Escalation:

• Development of systemic symptoms
• Worsening local signs (increasing erythema, warmth, pain)
• Development of fluctuance or drainage
• Spreading infection beyond initial margins 1

Conclusion

For this 65-year-old diabetic male with a foot wound showing erythema without fluctuance or drainage, Keflex (cephalexin) is an appropriate first-line antibiotic choice. The infection appears mild based on the limited information provided, and cephalexin provides good coverage against the most common pathogens in this setting. Close follow-up within 48-72 hours is essential to ensure appropriate response to therapy.