Is Tinea Unguium Still Widely Incurable?

Abstract

Tinea unguium, especially of the feet, for ages has been looked on as an incurable disease. Today, therapeutic outcome is still controversial. To evaluate the present state of antifungal therapy of dermatophytoses of the nails, a survey of the pertinent literature has been performed. The introduction of griseofulvin three decades ago was first considered a major breakthrough. Today, however, conventional griseofulvin treatment regimens must be called disappointing in terms of clinical and microbiological cure to be achieved. Cure rates of 40% to 100% have been reported for fingernail infections, but only 3% to 38% for toenail tinea. Microbiological cure rates look only slightly better. Limited experience suggests that additional measures such as surgical nail avulsion or topical antifungal treatment might improve therapeutic outcome. Toenail avulsion increases cure rates to 47% to 82%. The lack of an adequate follow up, however, makes all statements questionable. Results are only limited with respect to newly developed oral antifungal agents. Whereas ketoconazole treatment had to be omitted due to its hepatotoxic effect, its congener, intraconazole, is under investigation. High cure rates have been obtained in a preliminary study with oral terbinafine, 0.25 g/d, for 12 months, which have cleared toenail tinea in 15 of 17 patients. The value of topical treatment alone has not yet been definitely established. The application of a topical azole (bifonazole) in combination with chemical nail avulsion, using urea paste under occlusion, has resulted in negative cultures in 62% of the patients 3 months after the end of treatment.