Treatment of Infected Ingrown Toenails
For a mild localized bacterial infection of an ingrown toenail, topical mupirocin ointment applied three times daily is the preferred first-line antibiotic, combined with antiseptic soaks and mechanical management of the ingrown nail edge. 1, 2
Initial Management Approach
Systemic antibiotics are not necessary and do not improve healing outcomes in locally infected ingrown toenails when combined with appropriate local treatment. 3 A randomized controlled trial demonstrated no significant difference in healing time between patients receiving chemical matrixectomy alone (2.0 weeks) versus those receiving matrixectomy plus oral antibiotics (1.9 weeks). 3
Topical Antibiotic Selection
- Mupirocin 2% ointment applied three times daily achieves 94% pathogen eradication rates and 71% clinical efficacy in bacterial skin infections, making it the optimal topical choice when infection is confirmed. 1
- Mupirocin demonstrates superior activity against Staphylococcus aureus and Streptococcus species, the primary bacterial pathogens in acute paronychia. 4, 5
Essential Adjunctive Measures
Daily antiseptic soaks are critical for infection control:
- Apply dilute vinegar soaks (50:50 dilution) to nail folds twice daily for 10-15 minutes. 2
- Alternatively, use 2% povidone-iodine solution topically. 2
- For Pseudomonas infections (recognizable by green or black nail discoloration), antiseptic agents like octenidine are preferred. 5
Mechanical management of the ingrown nail edge must be addressed simultaneously:
- Tape the nail fold away from the nail plate to relieve pressure. 2
- Insert dental floss or cotton wisps under the ingrown nail edge to separate it from underlying tissue. 2, 6
- Consider gutter splinting with a flexible tube placed over the lateral nail edge. 2
When to Culture
Obtain bacterial culture if purulent drainage is present to guide antibiotic selection, particularly if initial topical therapy fails. 2 This is especially important given the possibility of Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus. 5
Important Clinical Caveats
Avoid systemic antibiotics unless:
- Cellulitis extends proximal to the hallux interphalangeal joint. 3
- The patient is immunocompromised or has peripheral vascular disease. 3
- There is documented systemic infection with fever or lymphangitis. 4
Do not use topical corticosteroids if active infection with pus is present, as steroids should be stopped or avoided until infection is controlled. 2 However, mid-to-high potency topical steroid ointment applied twice daily to nail folds is appropriate for inflammatory edema and pain once infection is treated. 2
Chronic paronychia is frequently non-infectious and represents contact dermatitis that may be secondarily colonized by fungi (Candida parapsilosis, C. guilliermondii) rather than bacteria. 4, 5, 7 In these cases, topical imidazole antifungals alternating with antibacterial agents are more appropriate than antibiotics alone. 2
Definitive Treatment Considerations
If conservative measures fail after 1-2 weeks, partial nail avulsion with phenolization of the nail matrix is more effective than continued medical management and prevents recurrence in the majority of cases. 6 Oral antibiotics before or after phenolization do not improve outcomes. 6