From the Guidelines
The primary treatment for extensive dermatophytosis is oral antifungal medication, specifically terbinafine, due to its higher efficacy and tolerability compared to itraconazole, as evidenced by a multicentre, randomized trial involving 508 subjects 1. Recommended regimen:
- Terbinafine: 250 mg once daily for 6-16 weeks, depending on the severity and location of the infection, with fingernail infections typically requiring 6 weeks of treatment and toenail infections requiring 12-16 weeks 1.
- Alternatively, itraconazole: 200 mg once daily for 12 weeks continuously, or as pulse therapy at a dose of 400 mg per day for 1 week per month, with two pulses recommended for fingernail onychomycosis and three pulses for toenail onychomycosis 1, 2. In addition to oral medication, topical antifungal creams should be applied to affected areas twice daily, with options including:
- Clotrimazole 1% cream
- Miconazole 2% cream
- Ketoconazole 2% cream
Patients should also:
- Keep affected areas clean and dry
- Avoid sharing personal items like towels or clothing
- Wash bedding and clothing in hot water regularly
- Wear breathable, loose-fitting clothing Treatment duration may need to be extended for severe cases or those involving the scalp or nails, with improvement expected within 2-4 weeks, but complete resolution may take longer 3. This approach is effective because oral antifungals reach the deeper layers of skin and nails, while topical treatments address surface fungal growth, providing comprehensive treatment for extensive infections, and good hygiene practices help prevent reinfection and spread to others.
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 treatment for extensive dermatophytosis is not directly addressed in the provided drug label, as it only mentions the treatment of onychomycosis due to dermatophytes.
- The label does not provide information on the treatment of extensive dermatophytosis.
- Terbinafine is indicated for the treatment of onychomycosis, but its use for extensive dermatophytosis is not mentioned 4.
From the Research
Treatment Options for Extensive Dermatophytosis
The treatment for extensive dermatophytosis typically involves the use of antifungal medications. Some studies have investigated the efficacy and safety of different treatment options, including:
- Terbinafine, an allylamine antifungal agent, which has demonstrated excellent fungicidal activity against dermatophytes 5, 6
- Combination therapy of oral terbinafine and itraconazole, which has shown to be effective and safe in the management of dermatophytosis 7
- High-dose terbinafine (500 mg once daily) for a shorter duration (2-6 weeks), which has been found to be efficacious and safe in treating patients with superficial dermatophytosis 8
- Pulse therapy with oral terbinafine, which has been proposed as a possible alternative for treating onychomycosis caused by dermatophytes, with a quarterly regimen showing no statistical differences in effectiveness or side effects compared to conventional dosing 9
Key Findings
Some key findings from the studies include:
- Terbinafine has a high mycological cure rate (>80%) in patients with dermatophyte onychomycosis 5, 6
- Combination therapy of oral terbinafine and itraconazole achieved maximum clinical and mycological cure (90%) in patients with dermatophytosis 7
- High-dose terbinafine (500 mg once daily) for a shorter duration (2-6 weeks) showed very good response in 87-92% of patients with superficial dermatophytosis 8
- Pulse therapy with oral terbinafine (500 mg/day for 7 days every 3 months) was found to be a possible alternative for treating onychomycosis caused by dermatophytes, with no statistical differences in effectiveness or side effects compared to conventional dosing 9