Filed under: Anti-Infectives.
Onychomycosis is a fungal infection of the nail bed, matrix, or plate. It accounts for one third of fungal skin infections and one half of all nail dystrophies. Infection is more common in toenails than fingernails and is usually associated with tinea pedis. Infection can be caused by dermatophytes and other molds as well as by yeasts.Infection usually starts at the distal, free edge of the nail. The edge of the nail is discolored white-yellow-brown and an accumulation of subungual white hyperkeratosis lifts the nail from the bed. The nail surface itself can become rough, furrowed, and brittle, especially in Candida infections. If all nails are affected, the dystrophy is likely noninfectious (i.e., psoriasis, lichen planus, trauma). If diagnosis is in doubt, fungal infection can be confirmed by potassium hydroxide preparation or culture.Treatment of onychomycosis can be very challenging. Topical treatment even with newer agents such as ciclopirox (Penlac), rarely achieves cure. Systemic regimens can be effective, but relapses, drug interactions, and hepatic or hematpoietic toxicity are common. Terbinifine (Lamisil) 250 mg daily for 6 (fingernails) to 12 (toenails) weeks is very effective, but complete blood cell count and liver enzyme tests must be monitored. Itraconazole (Sporanox) is also effective in a 6- to 12-week regimen of 200 mg daily. Liver enzyme tests should be monitored with itraconazole as well, but not when using pulse therapy. Pulse therapy is itraconazole 200 mg daily for 1 week during each of 2 to 4 months. There is also an effective pulse therapy regimen using fluconazole (Diflucan), but this is not approved by the Food and Drug Administration. Fluconazole 150 to 450 mg once weekly is given for 3 to 12 months. Liver enzymes need not be monitored when prescribing fluconazole.The true relapse rate of onychomycosis is difficult to measure. If culture was not initially performed, it should be done for relapses before another treatment is considered. Controlling moisture and tinea pedis may help prevent relapses.*116/348/5* cheapodrugs.com