Background. The prevalence of onychomycosis, the most frequent cause of nail disease, ranges from 2% to 13%. Standard treatments include debridement, topical medications, and systemic therapies. This study assesses the efficacy and tolerability of topical application of 1% clotrimazole solution compared with that of 100% Melaleuca alternifolia (tea tree) oil for the treatment of toenail onychomycosis.
Methods. A double-blind, multicenter, randomized controlled trial was performed at two primary care health and residency training centers and one private podiatrist's office. The participants included 117 patients with distal subungual onychomycosis proven by culture. Patients received twice-daily application of either 1% clotrimazole (CL) solution or 100% tea tree (TT) oil for 6 months. Debridement and clinical assessment were performed at 0, 1, 3, and 6 months. Cultures were obtained at 0 and 6 months. Each patient's subjective assessment was also obtained 3 months after the conclusion of therapy.
Results. The baseline characteristics of the treatment groups did not differ significantly. After 6 months of therapy, the two treatment groups were comparable based on culture cure (CL = 11%, TT = 18%) and clinical assessment documenting partial or full resolution (CL = 61%, TT = 60%). Three months later, about one half of each group reported continued improvement or resolution (CL = 55%; TT = 56%).
Conclusions. All current therapies have high recurrence rates. Oral therapy has the added disadvantages of high cost and potentially serious adverse effects. Topical therapy, including the two preparations presented in this paper, provide improvement in nail appearance and symptomatology. The use of a topical preparation in conjunction with debridement is an appropriate initial treatment strategy.
Key words. Onychomycosis; mycoses; nails; nail diseases; clotrimazole; administration, topical.
(J Fam Pract 1994; 38:601-605)
The prevalence of onychomycosis, the most frequent cause of nail disease,(1)(2)(3) ranges from 2% to 13%. Onychomycosis is caused by dermatophyte infections, the most common of which is Trichophyton rubrum; yeast (Candida spp); and occasionally molds. Three treatment modalities are available: debridement to eliminate affected keratin, topical medications, and systemic therapy. Topical therapy may have limited effectiveness because of poor penetration of the medication into the nail.(4)(5)
Oral therapies, beginning with griseofulvin in 1959, have been the "gold standard" treatment for dermatophyte onychomycosis.(6) Unfortunately, cure rates with griseofulvin range from 3% to 38%, and although rates may be higher when combined with toenail avulsion or topical medication or both, no significant follow-up data exist for these combined modalities.(7)(8)(9) Ketoconazole is attractive because it presumably treats yeast as well as dermatophyte onychomycosis and shows a cure rate of 50% to 93% at 1 year,(5)(10)(11) which is much higher than that of griseofulvin. Although side effects are rare, they can include pruritus, idiosyncratic liver dysfunction,(12) and gynecomastia.(10) Furthermore, about 50% of toenail infections recur 4 years after the completion of treatment.(13) Itraconazole has cure rates ranging from 4% to 92% with potentially fewer side effects,(14)(15)(16)(17)(18) but thus far, it has been evaluated only in small studies. Follow-up data beyond 1 year are unavailable. Fluconazole has been used by some physicians...