What is the treatment for a fingernail bed infection?

Treatment of Fingernail Bed Infections

For bacterial nail bed infections, amoxicillin-clavulanic acid 875/125 mg twice daily for 7-10 days is the first-line treatment due to its excellent coverage against common causative organisms including Staphylococcus aureus and other gram-positive bacteria. 1

Diagnosis and Clinical Presentation

Bacterial nail bed infections typically present with:

• Erythema, swelling, and pain around the nail fold
• Purulent discharge
• Separation of nail from nail bed
• Possible subungual abscess or hematoma

It's critical to differentiate between bacterial and fungal infections:

• Bacterial infections: acute onset, painful, erythematous
• Fungal infections: chronic, typically painless, characterized by nail thickening and discoloration

Treatment Algorithm for Fingernail Bed Infections

1. Bacterial Paronychia (infection of nail folds)

Mild to Moderate Infection:

• Warm soaks with or without Burow solution or 1% acetic acid for 10-15 minutes, 3-4 times daily 2
• Topical antibiotics with or without topical steroids if simple soaks don't relieve inflammation
• Oral antibiotics: Amoxicillin-clavulanic acid 875/125 mg twice daily for 7-10 days 1
• For suspected MRSA: Trimethoprim-sulfamethoxazole (TMP-SMZ) 160/800 mg twice daily 1

If Abscess Present:

• Surgical drainage is essential
• Culture and sensitivity testing should guide antibiotic selection
• Continue oral antibiotics as above

2. Candida Nail Infection

Candida infection accounts for 5–10% of all nail infections and is more common in fingernails than toenails 3.

Treatment options:

• For paronychia with Candida: Apply antiseptics to the proximal part of the nail, allowing them to wash beneath the cuticle 3
• Alternating imidazole lotion with antibacterial lotion until cuticle integrity is restored 3
• For invasive nail plate infection: Oral itraconazole 400 mg daily for 1 week per month, repeated for 2 months 3

3. Fungal Nail Infections (Onychomycosis)

For dermatophyte infections:

• First-line: Oral terbinafine 250 mg daily for 6 weeks for fingernails 4, 5
• Alternative: Itraconazole 200 mg twice daily for 1 week per month, repeated for 2 months 3

For superficial white onychomycosis or early distal infection:

• Topical antifungals may be sufficient:
  • Amorolfine 5% nail lacquer applied once or twice weekly 3
  • Ciclopirox 8% nail lacquer 5

Special Considerations

Prevention of Recurrence

• Keep hands dry and out of water when possible 3
• Avoid friction and pressure on nail folds
• Avoid picking or manipulating the nails
• Apply petrolatum around nails for lubrication 3

Common Pitfalls to Avoid

1. Misdiagnosis: Failing to differentiate between bacterial and fungal infections can lead to inappropriate treatment
2. Inadequate drainage: Abscesses require proper drainage for effective treatment
3. Inappropriate antibiotic selection: Using narrow-spectrum antibiotics may fail to cover common pathogens
4. Delayed treatment: Prompt intervention prevents progression to more severe infection
5. Neglecting underlying conditions: Immunosuppression, diabetes, or peripheral vascular disease may complicate treatment

Treatment Failure

If initial treatment fails:

• Reassess diagnosis with culture and sensitivity testing
• Consider surgical consultation for extensive infection
• Evaluate for underlying conditions that may impair healing
• Consider alternative antibiotics based on culture results

By following this algorithm and understanding the differences between bacterial and fungal nail infections, providers can effectively treat fingernail bed infections and prevent complications.