Topical antifungal drugs in the treatment of tinea pedis, tinea cruris, and tinea corporis

Single Dose Topical Application of Clotrimazole for the Treatment of Otomycosis: Is This Enough?

Background and Objectives

To determine the efficacy of filling the external auditory meatus with 1% clotrimazole at a single visit for the treatment of otomycosis.

Subjects and Methods

This prospective study included 40 patients who were referred to our clinic with complaints of ear itching, pain, and fullness, and were diagnosed with unilateral otomycosis. After cleaning the mycotic hyphae from the external auditory meatus, the ear canal was filled with 1% clotrimazole, using an intravenous catheter and syringe. The patients received follow-up examinations on post-treatment days 7, 15, and 45.

Results

The follow-up otomicroscopic examinations revealed that 95% of the ear canals were entirely clean and that all symptoms had resolved. The post-treatment scores of pain, aural fullness and itching were significantly lower than the pre-treatment scores (p<0.01).

Conclusions

Filling the external auditory meatus with 1% clotrimazole at a single visit is an easy, efficient, and cost-effective treatment for otomycosis. Additionally, high patient compliance makes this treatment superior to long-term topical therapy.

Permeation of ciclopirox across porcine hoof membrane: effect of pressure sensitive adhesives and vehicles

The purpose of this study was to investigate the effects of various pressure sensitive adhesives (PSA) on the penetration of ciclopirox across porcine hoof membrane. In addition, the influence of various vehicles on the permeation of ciclopirox from a PSA matrix across porcine hoof membrane was evaluated using a plastic penetration chamber containing poloxamer gel at 32 degrees C. Ciclopirox in poloxamer gel was extracted, derivatized and analyzed by HPLC. Ciclopirox showed highest permeability from an acrylic adhesive with a hydroxyl functional group, and this was followed by styrene-isoprene-styrene, styrene-butadiene-styrene, silicone and polyisobutylene adhesives in order. In addition, N-methyl-2-pyrrolidone (NMP), polypropylene glycol 400 (PPG 400), dimethylsulfoxide (DMSO), Labrasol, mercaptoethanol and Transcutol showed excellent permeation enhancing effects in a styrene-isoprene-styrene adhesive. A porcine hoof membrane treated with NMP changed from the non-helical phase to the helical phase, and another treated with DMSO showed a S=O peak shift to lower wavelength.

Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: a randomized, placebo-controlled, blinded study

Tea tree oil has been shown to have activity against dermatophytes in vitro. We have conducted a randomized, controlled, double-blinded study to determine the efficacy and safety of 25% and 50% tea tree oil in the treatment of interdigital tinea pedis. One hundred and fifty-eight patients with tinea pedis clinically and microscopy suggestive of a dermatophyte infection were randomized to receive either placebo, 25% or 50% tea tree oil solution. Patients applied the solution twice daily to affected areas for 4 weeks and were reviewed after 2 and 4 weeks of treatment. There was a marked clinical response seen in 68% of the 50% tea tree oil group and 72% of the 25% tea tree oil group, compared to 39% in the placebo group. Mycological cure was assessed by culture of skin scrapings taken at baseline and after 4 weeks of treatment. The mycological cure rate was 64% in the 50% tea tree oil group, compared to 31% in the placebo group. Four (3.8%) patients applying tea tree oil developed moderate to severe dermatitis that improved quickly on stopping the study medication.

Superficial fungal infection of the skin. Where and how it appears help determine therapy

Superficial fungal infections of the skin are a common presentation in clinical practice. Any skin surface, the mucous membranes, nail plates, and nail beds can be affected. Tinea pedis is the most common fungal infection and may affect up to 70% of the adult population worldwide. Ubiquitous candidal organisms are found in the oral flora of many healthy persons and result in infection in the presence of certain host factors or immunodeficiency disorders. Onychomycosis has had an increasing incidence worldwide, and it now accounts for almost half of all nail disorders. These and many other infections can have varying presentations as well as features that resemble nonfungal disorders. Therefore, it is important that primary care physicians are familiar with the many cutaneous fungal infections and their differential diagnosis to ensure that appropriate therapy is selected.

Tinea gladiatorum: wrestling's emerging foe

Tinea corporis, or ringworm, has become a common nuisance in competitive wrestling. Although it is a fairly benign infectious skin disease, it has significant effects on the ability of a wrestler to compete because of infection control issues. Very little has been published in the medical literature describing this problem. The majority of the literature has described outbreaks in an isolated group of wrestlers. One must examine ringworm infections in wrestlers as an entity distinct from tinea corporis infections typically seen in the paediatric population, thus the term 'tinea gladiatorum'. Tinea gladiatorum outbreaks have been caused by the dermatophyte, Trichophyton tonsurans. The epidemiology and microbiology point to person-to-person contact as the main source of transmission in wrestlers. The clinical features of tinea gladiatorum may or may not be consistent with those found in the general population. Ancillary tests, including potassium hydroxide preparations and fungal cultures may have to be done to confirm the diagnosis. Treatment guidelines for tinea corporis have failed to produce the desired goals in this particular population. More research studying different treatment regimens in the wrestling environment is needed to define the optimal treatment to return wrestlers to competition quickly without putting other wrestlers at risk for infection. Intuitive hygiene practices have been suggested to prevent spread of the infection, but they have not been substantiated. Anecdotal reports suggest that hygiene practices fall short of producing adequate primary or secondary prevention. Pharmaceutical prophylaxis has been effective, but universal drug prophylaxis carries risks including drug adverse effects and potential drug resistance. The role of potential asymptomatic carriers of dermatophytes has yet to be elucidated in the origin and/or perpetuation of tinea gladiatorum outbreaks. There are many unanswered questions about tinea gladiatorum. Sports medicine professionals must work to define this entity more completely before making recommendations about treatment, prevention and infection control. The ultimate goal is the eradication of tinea infections from the wrestling world. Energy should be focused on primary and secondary prevention, as well as treatment. Without a thorough knowledge of tinea gladiatorum as a distinct disease entity, wrestling has been losing its battle with this formidable opponent.

Efficacy and tolerability of terbinafine 1% topical solution used for 1 week compared with 4 weeks clotrimazole 1% topical solution in the treatment of interdigital tinea pedis: a randomized, double-blind, multi-centre, 8-week clinical trial

In this double-blind clinical trial 429 patients (217 terbinafine and 212 clotrimazole) were randomized to receive twice daily terbinafine 1% topical solution for 1 week followed by a vehicle application for 3 weeks, or 1% clotrimazole solution for 4 weeks. Patients were evaluated clinically and mycologically at baseline and then at weeks one, two, four (end of treatment), and eight (end of follow-up). To be evaluable the patient needed to have a positive culture for a dermatophyte and positive KOH microscopy and a clinical diagnosis of tinea pedis (interdigital type) at baseline. Effective treatment of tinea pedis was recorded in 181 of 217 (83%) of patients treated for 1 week with terbinafine 1% solution and 174 of 212 (82%) of patients treated for 4 weeks with clotrimazole 1% solution. Mycological cure and disappearance of signs and symptoms were similar at each assessment visit in the two groups. In the subgroup of patients without any protocol violation the mycological cure rate was 95% (164 of 173) with terbinafine solution and 91% (159 of 174) with clotrimazole solution (P = 0.05). Adverse events believed to be drug-related occurred in 13 patients in the terbinafine group and 11 in the clotrimazole group (4 to 5% in each group). The events were primarily local skin reactions of mild to moderate intensity. It can be concluded that terbinafine 1% solution used for 1 week to treat tinea pedis is well tolerated and at least as effective as clotrimazole 1% solution used for 4 weeks.

Positively and negatively charged submicron emulsions for enhanced topical delivery of antifungal drugs

Charged submicron emulsions are a priori interesting candidates for the delivery of drugs in and/or through the skin. In the present study, it was possible by using stearylamine or deoxycholic acid (DCA) to incorporate either econazole or miconazole nitrate, respectively, in positively and negatively charged submicron emulsions. The investigation of the relationship between the physicochemical properties of the vehicles, especially the charge of the emulsion and skin permeation, was conducted ex vivo during percutaneous absorption experiments using hairless female rat skin. In addition, drug quantification was carried out using two different analytical techniques (HPLC and radioactivity measurements) in order to examine if the drug analysis approach might affect the results. The results clearly indicate that the surface-modified droplets have a significant influence on the diffusion through the skin. Furthermore, the method of preparation of the formulation and subsequently the analytical method of drug concentration measurement are able to influence the results of percutaneous experiment.

Overview of topical therapy for common superficial fungal infections and the role of new topical agents

Until recently the treatment options for superficial fungal infections have been limited mainly to the use of fungistatic drugs of the imidazole class, discovered in the 1960s. The recent development of allylamine and benzylamine compounds provides antifungal agents with fungicidal mechanisms of action. Both imidazole and allylamine/benzylamine drugs interfere with the production of ergosterol, an essential component of the fungal cell membrane; however, the newer drugs act at an earlier stage of the metabolic pathway than the azoles and cause an accumulation of squalene in the fungal cell, which leads to cell death. In vitro test results show that allylamine/benzylamine minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) are lower than the MICs and MFCs of azoles tested by the same methods. In studies using animal models of dermatophytosis, results have shown the efficacy of the allylamine/benzylamine drugs to be superior to that of azole drugs. Clinical trials have also shown significant differences favoring allylamine/benzylamine drugs over imidazoles in the treatment of dermatophytosis. The fungicidal drugs provide earlier evidence of efficacy, higher cure rates with shorter treatment periods, and lower relapse rates than imidazoles in direct-comparison studies. The allylamine/benzylamine drugs have also shown high cure rates in patients with candidiasis.

1992 AAD Award for Excellence in Education: The Integrated Basic and Clinical Science Conference Series at the University of Texas Southwestern Medical Center

This article was written to share information concerning the establishment and implementation of a successful, integrated basic and clinical science conference series for resident trainees in dermatology. We discuss the underlying philosophy and describe the concepts employed in, and the dynamics that have resulted from, this educational experiment. Finally, we include the schedule and references for the 1993-1994 academic year.