From the FDA Drug Label
Terbinafine tablets, USP are indicated for the treatment of onychomycosis of the toenail or fingernail due to dermatophytes (tinea unguium). The recommended treatment for interdigital erosions between the third and fourth toes of the right foot with a potassium hydroxide (KOH) preparation from skin scraping showing segmented hyphae, indicative of a fungal infection, cannot be determined from the provided drug label as it specifically mentions the treatment of onychomycosis of the toenail or fingernail, not interdigital erosions. Key points:
- The drug label is for terbinafine (PO) for the treatment of onychomycosis.
- The label does not mention interdigital erosions.
- No conclusion can be drawn from the provided information regarding the treatment of interdigital erosions with terbinafine 1.
From the Research
For erosions between the third and fourth interdigital spaces of the right foot with positive potassium hydroxide preparation showing segmented hyphae, I recommend treatment with topical antifungal medication such as terbinafine 1% cream applied twice daily for 2-4 weeks or clotrimazole 1% cream applied twice daily for 4 weeks. This condition represents tinea pedis (athlete's foot) with interdigital involvement, confirmed by the presence of fungal hyphae on KOH preparation, as discussed in 2. The treatment aims to eradicate the fungal infection while preventing maceration and secondary bacterial infection.
Key Considerations
- The interdigital spaces provide a warm, moist environment ideal for dermatophyte growth, so maintaining dryness is crucial for treatment success and preventing recurrence.
- Keep the affected area clean and dry, washing daily with mild soap and thoroughly drying afterward.
- Wear clean cotton socks and well-ventilated shoes, changing them regularly.
- Avoid walking barefoot in public areas.
Treatment Options
- Topical terbinafine 1% cream applied twice daily for 2-4 weeks or clotrimazole 1% cream applied twice daily for 4 weeks are effective treatment options, as shown in 3.
- For more severe or resistant cases, oral terbinafine 250mg daily for 2 weeks or fluconazole 150mg weekly for 2-4 weeks may be necessary, as discussed in 4.
Importance of Diagnosis
- Accurate diagnosis is necessary for effective treatment, and diagnosis is usually based on history and clinical appearance plus direct microscopy of a potassium hydroxide preparation, as stated in 2.
- The presence of inflammation may necessitate the use of an agent with inherent anti-inflammatory properties or the use of a combination antifungal/steroid agent, as mentioned in 2.