What antibiotics are used to treat an ingrown toenail infection?

Antibiotic Treatment for Infected Ingrown Toenails

For mild to moderate infected ingrown toenails, start oral trimethoprim-sulfamethoxazole or amoxicillin-clavulanate as first-line therapy, with clindamycin reserved for penicillin-allergic patients. 1

Severity Classification and Treatment Algorithm

Mild Infections

Mild infections present with local inflammation, pain, and minimal discharge without systemic symptoms. 1

First-line antibiotics:

• Oral trimethoprim-sulfamethoxazole 1
• Oral amoxicillin-clavulanate 1, 2
• Clindamycin for penicillin allergy 1

Duration: 1-2 weeks of treatment typically suffices 3, 1

Concurrent local measures:

• Topical povidone-iodine 2% soaks 3, 1
• Topical antibiotics with corticosteroids to reduce inflammation 3, 1
• Warm water soaks 1

Moderate Infections

Moderate infections show more extensive inflammation, purulent discharge, and pain limiting instrumental activities of daily living. 1

First-line antibiotics:

• Oral trimethoprim-sulfamethoxazole 1
• Oral amoxicillin-clavulanate 1
• Oral levofloxacin 1
• Oral clindamycin 1

Duration: 2-4 weeks of treatment 3, 1

Additional measures:

• Obtain bacterial cultures if infection is suspected 4
• Continue topical antimicrobial measures concurrently 1
• Monitor response within 2-5 days 1

Severe Infections

Severe infections involve significant inflammation extending beyond the toe, systemic symptoms, or limitation of self-care activities. 1

Initial therapy requires intravenous antibiotics:

• Piperacillin-tazobactam IV 1
• Levofloxacin or ciprofloxacin IV with clindamycin 1
• Vancomycin 30 mg/kg/day in 2 divided doses IV if MRSA is suspected 1

MRSA coverage indications:

• Prior MRSA infection 1
• Recent antibiotic exposure 1
• Failure of initial beta-lactam therapy 1

Key Microbiological Considerations

Staphylococcus aureus is the most common pathogen in infected ingrown toenails, but polymicrobial infections including gram-negative organisms can occur. 1 Pseudomonas aeruginosa may be present, particularly in chronic cases with green or black nail discoloration. 5

Critical Management Pitfalls

Antibiotics alone are insufficient without appropriate wound care. 3 The nail acts as a foreign body causing ongoing inflammation and infection. 6

Essential concurrent measures:

• Correct improper footwear 1
• Address hyperhidrosis if present 7
• Consider partial nail avulsion if painful hematoma or subungual abscess develops 3, 4
• Reassess after 2 weeks; if no improvement, consider surgical intervention 3, 1

Treatment Monitoring

Reassess within 2-5 days for outpatients. 1 If the infection worsens or fails to improve with oral antibiotics and local care, obtain cultures and consider:

• Changing antibiotics based on culture results 1
• Surgical consultation for partial or complete nail avulsion 3
• Escalation to IV therapy for severe or refractory cases 1

Special Considerations

Do not use prophylactic antibiotics for clean puncture wounds without signs of infection. 4 Antibiotics are only indicated when infection is clinically evident with increased pain, redness, swelling, purulent drainage, or warmth. 4

Amoxicillin-clavulanate should be taken with meals to reduce gastrointestinal upset. 2 Patients must complete the full course even if symptoms improve early to prevent resistance development. 2