What is the treatment for a nailbed infection of the fingers with Keflex (cephalexin)?

Treatment of Nailbed Infections with Cephalexin

Cephalexin is an effective first-line antibiotic for bacterial nailbed infections of the fingers, particularly those caused by Staphylococcus aureus and Streptococcus pyogenes, which are the most common bacterial pathogens in these infections. 1

Diagnostic Considerations

• Bacterial nailbed infections typically present with pain, erythema, swelling, and sometimes purulent discharge around the nail fold 2
• Obtain bacterial cultures if infection is suspected to guide appropriate antibiotic therapy 3
• Distinguish between bacterial infections and fungal infections (onychomycosis), as treatment approaches differ significantly 4

Treatment Algorithm for Nailbed Infections

First-Line Treatment

• For mild to moderate bacterial nailbed infections:
  • Cephalexin 500 mg orally four times daily for 7-10 days for adults 1, 5
  • For children: 25-50 mg/kg/day divided into four doses 6
  • Cephalexin is particularly effective against Staphylococcus aureus and Streptococcus pyogenes, the most common causes of bacterial nailbed infections 1, 5

Adjunctive Measures

• Warm soaks with or without Burow solution or 1% acetic acid three to four times daily for 15 minutes 2
• If abscess is present, drainage is mandatory before antibiotic therapy 2
• Keep the affected area clean and dry between soaks 3
• Avoid manipulation of the cuticles and nail biting 3

For Severe or Non-Responsive Infections

• If no improvement after 48-72 hours of treatment, reassess for:
  • Presence of undrained abscess 3
  • Need for broader antibiotic coverage 3
  • Possible fungal co-infection 4

Special Considerations

• If painful hematoma or subungual abscess is suspected, partial or total nail avulsion may be required 3
• For chronic or recurrent infections, address underlying factors such as:
  • Occupational exposures (frequent water immersion) 2
  • Nail trauma 2
  • Immunocompromised status 3

Differentiating Bacterial vs. Fungal Nail Infections

• Bacterial infections typically have acute onset with pain, erythema, and sometimes purulent discharge 2
• Fungal infections (onychomycosis) usually present with gradual nail discoloration, thickening, and minimal pain 3
• If fungal infection is suspected, appropriate antifungal therapy should be initiated instead of antibiotics 3

Common Pitfalls to Avoid

• Treating fungal infections with antibiotics, which will be ineffective 4
• Failing to drain abscesses when present 2
• Inadequate duration of antibiotic therapy leading to recurrence 3
• Not addressing underlying factors that may predispose to recurrent infections 2

Follow-up

• Reassess after 2 weeks of treatment 3
• If infection worsens or does not improve, consider:
  • Alternative antibiotics based on culture results 3
  • Surgical intervention for drainage 3
  • Specialist referral if infection is severe or recurrent 2