Antibiotic Treatment for Skin Infection After Finger Cut
For a simple skin infection following a finger cut, oral cephalexin 500 mg four times daily or dicloxacillin 500 mg four times daily for 7-10 days is the recommended first-line treatment. 1
Treatment Algorithm
Assess Infection Severity
Mild, uncomplicated infection (no systemic signs):
- Cephalexin 500 mg orally four times daily is the preferred oral agent for methicillin-susceptible Staphylococcus aureus (MSSA), which causes most simple skin infections 1
- Dicloxacillin 500 mg orally four times daily is an alternative oral agent of choice for MSSA 1
- Amoxicillin-clavulanate 875/125 mg twice daily provides broader coverage if mixed flora is suspected 1
- Treatment duration: 7-10 days 1
For penicillin-allergic patients (non-immediate hypersensitivity):
- Cephalexin remains appropriate unless there is a history of immediate hypersensitivity reactions (urticaria, angioedema, bronchospasm, anaphylaxis) 1
For penicillin-allergic patients (immediate hypersensitivity):
- Clindamycin 300-450 mg orally three times daily 1
- Note: Clindamycin has potential for Clostridioides difficile-associated disease 1
If MRSA is Suspected or Confirmed
Community-acquired MRSA (CA-MRSA) coverage needed when:
- Patient has failed initial beta-lactam therapy 1
- Known MRSA colonization or previous MRSA infection 1
- Systemic toxicity present 1
Oral options for CA-MRSA:
- Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily 1
- Doxycycline 100 mg twice daily (avoid in children <8 years and pregnancy) 1
- Clindamycin 300-450 mg three times daily (provides coverage for both MRSA and beta-hemolytic streptococci) 1
Severe Infection Requiring IV Therapy
Indications for hospitalization and IV antibiotics:
- Rapidly progressive infection despite oral antibiotics 1
- Systemic toxicity (fever, tachycardia, hypotension) 1
- Immunocompromised host 1
- Deep tissue involvement or abscess requiring drainage 1
IV antibiotic options:
- Nafcillin or oxacillin 1-2 g every 4 hours IV for MSSA 1
- Cefazolin 1 g every 8 hours IV (more convenient than nafcillin, suitable for penicillin allergy except immediate hypersensitivity) 1
- Vancomycin 15-20 mg/kg/dose every 8-12 hours IV for MRSA 1
Special Considerations
If Contaminated or Dirty Wound
- Consider broader coverage with amoxicillin-clavulanate to cover mixed aerobic and anaerobic bacteria 1
- Ensure adequate wound cleaning and debridement 1
Tetanus Prophylaxis
- Administer tetanus toxoid if not vaccinated within 10 years 1
- Tdap (tetanus, diphtheria, pertussis) is preferred over Td if not previously given 1
- For dirty wounds, give booster if >5 years since last dose 1
Common Pitfalls to Avoid
- Do not use trimethoprim-sulfamethoxazole or doxycycline as monotherapy if beta-hemolytic streptococci are likely, as their activity against streptococci is not well-defined 1
- Avoid topical antibiotics for anything beyond superficial impetigo with limited lesions—systemic therapy is needed for established infections 1
- Do not use rifampin as monotherapy due to rapid resistance development 1
- Linezolid should not be first-line due to cost and lack of superiority over less expensive alternatives 1