Effects of temperature, humidity, minor injury and washing on penetration of dermatophytes into human stratum corneum]

We evaluated the minimum time for penetration of Trichophyton mentagrophytes into human stratum corneum using an experimental model of tinea pedis. After fungal elements were applied on the surface of stratum corneum obtained from a healthy human heel, samples were incubated under designated conditions of temperature and humidity. The penetration of fungal elements was much faster at 35 degrees C than 27 degrees C despite the fact that the latter is an optimal temperature for fungal growth. At 35 degrees C and 100% humidity the minimum time required for penetration was one day. When we applied fungal elements on an abraded surface of stratum corneum, fungi penetrated within a half day under the same conditions. This suggests that minor injury of stratum corneum is a significant factor for infection. The development of tinea pedis does not occur frequently in daily life. We examined the effect of washing the surface of stratum corneum to which T. mentagrophytes had been applied. The samples were incubated under conditions simulating daily life: i.e. with 80% humidity for 8 hours, and 100% humidity for 16 hours. After washing, nearly all the fungal elements had been removed from the surface of stratum corneum within one day. The data suggests that to prevent tinea pedis, daily washing of soles and interdigital regions is effective.     

Effect of temperature, humidity and minor injury to the penetration of dermatophytes into human stratum corneum]

We evaluated the minimum period for penetration of Trichophyton mentagrophytes into human stratum corneum using an experimental model of tinea pedis. Fungal elements were applied to the surface of stratum corneum which were obtained from a healthy human heel, and samples were incubated under a designated condition of temperature and humidity. Thirty-five degrees, which is the approximate temperature of the surface of human skin, seemed more suitable for penetration than 27C. The result also indicated that humidity was a more significant factor than temperature. In the following examination using T. mentagrophytes and T. rubrum, the minimum period for penetration at 100% humidity was 1 day with the former and 1.5 days with the latter. At 95% humidity, T. mentagrophytes penetrated into human stratum corneum on day 1.5 and T. rubrum penetrated on day 4. Humidity of the 4th interdigital space in daily life was calculated to be below 95% using a hygro-thermometer. Therefore, to wash the feet daily can prevent development of tinea pedis. When we applied fungal elements to a cut side of stratum corneum, fungi penetrated within a day at 100% and 95% humidity. In addition, fungi were able to penetrate at below 85% humidity, which they were unable to do when applied them to the surface side. We stress that minor injury of stratum corneum is also a significant factor of the development of tinea pedis.     

Susceptibility pattern among pathogenic species of Aspergillus to physical and chemical treatments.

Physical treatments, like heating or irradiation, may reduce the viability or eradicate Aspergillus conidia, which in turn might help to prevent infections by members of this genus. Chemical treatments can also prevent infection resulting from contaminated hospital fabrics or surfaces. Our objectives were to study the kinetics of survival of the conidia of pathogenic Aspergillus species, like A. fumigatus, A. flavus and A. niger, during exposure to heating at 60 degrees C and microwave irradiation. In addition, we evaluated the susceptibility patterns of Aspergillus conidia to such chemical agents as cupric sulphate and sodium hypochlorite. Heating the conidia of A. flavus and A. niger at 60 degrees C for 45 min was found to be fungicidal (reduction > 104 conidia/ml), but was not with A. fumigatus conidia. Short periods of microwave irradiation (40 s) resulted in a significant reduction of the viability of the conidia of these three Aspergillus species as a result of lethal membrane lesions. All Aspergillus species were similarly susceptible to cupric sulphate and sodium hypochlorite. Therefore, heating, microwave and the chemical treatments tested impaired significantly the viability of Aspergillus conidia, supporting the use of these methods as preventive measures among patients at risk.     

Prevalence and risk factors of tinea unguium and tinea pedis in the general population in Spain

This study prospectively evaluated the prevalence and risk factors of tinea unguium and tinea pedis in the general adult population in Madrid, Spain. One thousand subjects were clinically examined, and samples of nails and scales from the interdigital spaces of the feet were taken from those patients presenting with signs or symptoms of onychomycosis and/or tinea pedis, respectively. In addition, a sample from the fourth interdigital space of both feet was collected from all individuals with a piece of sterilized wool carpet. Tinea unguium was defined as a positive direct examination with potassium hydroxide and culture of the etiological agent from subjects with clinically abnormal nails. Patients with positive dermatophyte cultures of foot specimens were considered to have tinea pedis. The prevalence of tinea unguium was 2.8% (4.0% for men and 1.7% for women), and the prevalence of tinea pedis was 2.9% (4.2% for men and 1.7% for women). The etiological agents of tinea unguium were identified as Trichopyton rubrum (82.1%), followed by Trichopyton mentagrophytes var. interdigitale (14.3%) and Trichopyton tonsurans (3.5%). Trichophyton rubrum (44.8%) and Trichophyton mentagrophytes (44.8%), followed by Epidermophyton floccosum (7%) and T. tonsurans (3.4%), were the organisms isolated from patients with tinea pedis. The percentage of subjects who suffered simultaneously from both diseases was 1.1% (1.7% for men and 0.6% for women). In a multivariate logistic regression analysis, age (relative risk [RR], 1.03) and gender (RR, 2.50) were independent risk factors for tinea unguium, while only gender (RR, 2.65) was predictive for the occurrence of tinea pedis. In both analyses, the presence of one of the two conditions was associated with a higher risk for the appearance of the other disease (RR, >25).     

Dermatophyte flora at the dermatology clinic of Kimitsu Chuo Hospital from 1994 through 1999]

Kimitsu Chuo Hospital is located in the middle of Chiba Prefecture along Tokyo Bay. An epidemiological survey of dermatophytosis was made at the dermatology clinic of the hospital from January 1994 through December 1999. Dermatophytosis patients numbered 2,580 and disease types were composed of: tinea pedis 1,656 (64.2%), tinea unguium 377 (14.6%), tinea corporis 308 (11.9%), tinea cruris 139 (5.4%), tinea manuum 92 (3.6%), tinea capitis 6 (0.2%) and tinea profunda 2 (0.1%). Species frequencies in the 1,610 strains isolated from these patients were as follows: 929 (57.7%) of Trichophyton rubrum, 651 (40.4%) of T. mentagrophytes, 9 (0.6%) of Microsporum gypseum, 8 (0.5%) of M. canis, 8 (0.5%) of Epidermophyton floccosum and 5 (0.3%) of T. violaceum. The ratio of T.R/T.M was 1.43 in all the isolates, and 0.81 in the isolates from tinea pedis. These ratios were lower than those of the epidemiological survey of dermatomycoses in Japan in 1997. T. mentagrophytes was characteristically dominant in this hospital and resulted from a drastic increase in tinea pedis caused by this species in the summer season.     

Experimental studies on the penetration into the human stratum corneum of the dermatophyte]

We present results on the experimental penetration of Trichophyton mentagrophytes and T. rubrum under designated condition of humidity into human stratum corneum obtained from a healthy human heelregion. When mycelia were applied to the surface side of stratum corneum and then incubated at 100 % humidity, T. mentagrophytes and T. rubrum were observed in the stratum corneum on day 1 and day 1.5, respectively. At 95% humidity, T. mentagrophytes and T. rubrum penetrated on day 1.5 and day 4, and at 90% humidity, they penetrated on day 3 and day 7, respectively. At less than 85% humidity, no fungal elements of either strain were observed in stratum corneum for up to 7 days. These datasuggest that at least 90% humidity is necessary for these two fungi to penetrate into stratum corneum within a few days. However, when T. mentagrophytes was applied to the cutting side of the stratum corneum and thenincubated at more than 70% humidity, the mycelia were able to penetrate within a day. The same results were obtained when T. rubrum was applied on the cutting side and incubated at 95 and 100% humidity. T. rubrum was also able to penetrate into the stratum corneum within several days at 70 and 80% humidity. These results may indicate that not only persistent moisture but also minor injuries of stratum corneum are the most important factors in the development of tinea pedis.     

Comparative efficacies of commonly used disinfectants and antifungal pharmaceutical spray preparations against dermatophytic fungi.

Arthroconidia from five fungal strains belonging to three Trichophyton species, Trichophyton mentagrophytes, T. raubitschekii and T. tonsurans, were tested against commercial chemical disinfectants and pharmaceutical antifungal agents. The chemical disinfectants included chlorine, phenol, sodium dodecyl sulphate and several quaternary ammonium salts, while the two pharmaceutical preparations contained bifonazole and terbinafine as active agents. Arthroconidia were exposed to the antifungal agent either in a suspension solution for a given period of time and assayed for kill rate, or on a sprayed agar plate and monitored for surviving colonies over a period of 14 days. Chlorine (1%) and terbinafine (0.01%) were found to be high level disinfectants bringing about a rapid inactivation of conidia in all five strains. Phenol was equally effective against T. raubitschekii and T. tonsurans; however, T. mentagrophytes cells were able to survive for up to 1 h in 5% phenol. Quaternary ammonium compounds were less rapid in their action against dermatophytes and were needed at a level of about 0.5% to be completely fungicidal. Three commercial spray formulations with a range of 0.1 to 0.3% quaternary ammonium salts were fungistatic against T. mentagrophytes strains. Bifonazole (1%) was also fungistatic in its action against T. mentagrophytes. Sodium dodecyl sulphate (0.5%) was largely ineffective against Trichophyton arthroconidia.     

Epidemiological investigation of tinea pedis in groups of healthy students, research workers and females wearing boots]

The infection rate, causative dermatophytes, and dermatophyte dissemination of tinea pedis in young healthy Japanese were studied by direct microscopic examination, slant cultures, and foot-press culture method. Questionnaires on subjective symptoms and treatments were also distributed. Among fifty-eight medical students with a mean age of 23.9 years, thirteen (22.4%) showed positive by direct microscopic examination and T. mentagrophytes was more dominant than T. rubrum by slant cultures. In one hundred and sixteen student feet, twelve were infected and disseminating dermatophytes, four were infected but not disseminating, three were not infected but adhering dermatophytes. The infection rate of tinea pedis was thus 24.1%. Among thirty-seven research workers (mean age: 34.8), twenty-one (56.8%) showed positive by direct microscopic examination. All the dermatophytes isolated by slant cultures were T. mentagrophytes. In seventy-four feet, twenty-nine were infected and disseminating, ten were infected but not disseminating, and three were adhering dermatophytes. The infection rate was 64.9%. Among thirty-one females wearing boots (mean age: 21.0), seven (22.6%) were infected and T. mentagrophytes was more dominant. In sixty-two feet, eight were infected and disseminating, one was infected but not disseminating, and five were adhering dermatophytes. The infection rate of tinea pedis was quite high and T.r/T.m rate was low in the three groups. Most of the patients had had no treatment and were disseminating dermatophytes.     

Analysis of dermatophyte flora at a private clinic in Sapporo during the period 1992 to 2001]

Statistical analysis was made of a total of 5530 patients (6798 cases) of dermatophytoses presenting at our private clinic during the period 1992 to 2001. The number of patients and cases represents 8.0% and 9.8% of the entire outpatient population during that time, respectively. Sex ratio (male/female) was 1.5. Among the 6798 dermatophytoses cases, tinea pedis was most frequent (65.8%), followed by tinea unguium (20.7%), tinea cruris (7.2%), tinea corporis (3.9%), tinea manuum (2.4%) and tinea barbae (0.04%). The incidence of tinea unguium increased, whereas that of tinea pedis, tinea cruris, and tinea corporis decreased during this ten year period, and 35.8% of dermatophytoses patients had more than two clinical subtypes simultaneously. Three thousand seven hundred ninety-five dermatophytes were isolated during the survey. : Trichophyton rubrum (TR)(79.4%), Trichophyton mentagrophytes (TM)(19.5%), Microsporum canis (MC)(0.7%), Epidermophyton floccosum (EF) (0.3%), and Microsporum gypseum (MG) (0.1%). Compared with our previous analysis reported for the period 1982 to 1991, the frequency of dermatophytoses increased, especially among aged individuals. Of the clinical subtypes, tinea pedis and tinea unguium were higher, but tinea cruris and tinea corporis were lower, and tinea capitis was not seen in the current survey. Among dermatophytes, TR was increased and other types of fungi were decreased. TR was 4.08 times more common than TM; this ratio is higher than our previous report.     

Blood-free selective medium for isolation of Campylobacter jejuni from feces

A blood-free selective agar is described which contains charcoal, ferrous sulfate, sodium pyruvate, casein hydrolysates, cefazolin, and sodium deoxycholate (CCD agar). CCD agar was compared with Preston medium for isolation of Campylobacter jejuni from human feces, and isolation rates were similar on both media, but CCD agar was less selective. Temperature studies at 37 and 42 degrees C confirmed that incubation of direct plates at 42 degrees C for 48 h was necessary for maximum isolation of C. jejuni.     

Mycoses frequency in three communities in the North mountain of the State of Puebla

In order to know mycosis frequency in the North of the State of Puebla, Mexico, in habitants from the communities of Ayotoxco, Mazatepec and Zacatipan were studied. Previous medical study biological samples were submitted to direct examination, smear and culture. Histoplasmin and sporotrichin skin test were applied to 57 individual from Zacatipan. From 110 patients 146 mycological studies were performed. Eighty six cases (59%) of mycosis were detected: 43 finger or toenails onychomycosis, 25 tinea pedis, seven tinea capitis, four cases of tinea manum and, finally, five cases of seborrhoeic dermatitis and two of pitiriasis versicolor. We isolated: 18 streins of dermatophytes, mainly Trichophyton rubrum and T. mentagrophytes (11 and 5 strains respectively); 12 cultures of non-dermatophytes filamentous fungi; six cases of mycelia sterile; six yeast strains, most of them Candida spp but none C. albicans. From 57 patients to whom skin tests were applied, five of them (8.8%) were positive to both antigens; ten positive (17.6%) only to histoplasmin and eight (14%) to sporotrichin. This study showed that rural population from Puebla present a high frequency of superficial mycosis (61% of mycological studies). Considering the percentage of positive skin test we suppose that there are many not diagnosed sporotrichosis and histoplasmosis cases.     

A case of tinea capitis with a couple of nodular lesions possibly resulting from topical application of tacrolimus]

We herein report a case of tinea capitis initially showing a couple of nodular lesions. The patient was a 66-year-old woman who had seen a nearby dermatologist for itching on her head and had been treated with a topical steroid followed by tacrolimus application for one month. Because pseudolymphoma-like erythematous nodules developed at two sites, she visited us. Two weeks after stopping all medication, some slight scaling was found around these nodules. On KOH direct microscopic examination, many filamentous elements around hair shafts were observed. Biopsy of the nodules confirmed the destruction of hair follicles surrounded by granulomatous inflammation histologically. Grocott staining of the same specimen revealed a few short fungal hyphae as well as spores. She was also diagnosed as tinea pedis by direct microscopic examination of her feet. Trichophyton rubrum was isolated from scales of both her head and feet on Sabouraud's dextrose agar at 25 degrees C. Kerion celsi (KC) is usually clinically preceded by a gray patch or black dots. Such a typical course of KC, however, was not observed in our patient. Tacrolimus was thought to have possibly played an important role in modifying tinea capitis.     

Statistical study of dermatomycosis for 30 years (1968-1997) in sendai national hospital]

A statistical study on dermatomycoses for the 30 years from 1968 to 1997 in the dermatologic section of Sendai National Hospital was carried out with the following results. The total number of dermatomycosis patients was 14,259 and accounted for 9.59% of all new outpatients during this period. These cases of dermatomycoses were composed of the following: dermatophytoses 10,656, candidiasis 3,287, malassezia infection 566, sporothrichosis 20, aspergillosis 7, and chromomycosis 1. Annual changes in number of dermatophytoses varied in each clinical type: tinea corporis and tinea cruris had increased by the end of the 1970s, and there after decreased gradually until recent years. Tinea pedis and tinea unguium, on the contrary, increased after the 1980s. Age distribution of all clinical forms of dermatophytoses changed gradually, and its peak of the distribution curve shifted to an older site each year, while the number of younger generation patients decreased. Mycologically Trichophyton (T.) rubrum was mainly isolated from all types of dermatophytoses, and T. mentagrophytes followed. The ratio of these two species (R/M) in tinea pedis was 1.25, and the ratio of T. mentagrophytes was relatively high. Epidermophyton floccosum was continuously isolated, but its frequency in recent years has decreased. Microsporum canis infection increased from the middle period of this research, but after 1990 decreased gradually. The other dermatophytes were found sporadically. In recent years the species isolated have become more simplified. Among candidiasis, infantile candidiasis increased dramatically in the 1970s but soon decreased. Intertrigo type also increased in the same period and then decreased to an intermediate level. Paronychia, onychia and erosio interdigitale were constantly found in small numbers, while malassezia infection remained at a constant level and was found more in male patients.     

A novel method to estimate the contribution of the vapor activity of essential oils in agar diffusion assay.

By the combined use of agar diffusion, agar vapor and agar vapor-inhibitory assays, contribution of the vapor activity of essential oils was quantitatively estimated. The test organisms were Trichophyton mentagrophytes and Aspergillus fumigatus. Agar vapor assay was used to confirm the vapor activity of the oils. The parameter delta defined as a contribution index of the vapor activity was calculated by (1 - b-c/a-c) x 100, where a is inhibitory diameter in the diffusion assay, b is inhibitory diameter in the vapor-inhibitory assay and c is diameter of the sealed ring in the vapor-inhibitory assay (21 mm). Many of the essential oils examined showed a delta value near 100, thus providing the major contribution of the vapor activity to the inhibitory diameter. Essential oils containing aldehyde as major constituent showed low delta value, indicating the major inhibition was due to agar diffusion. Major essential oil components behaved similarly; the delta value was increased in the following order: aldehyde < phenol < alcohol < ester, oxide, hydrocarbon, indicating the enhanced contribution of the vapor activity in that order.     

Statistical study of dermatomycosis - observations in Sendai National Hospital over a 30 year period]

A statistical 30-year study of dermatomycosis in Sendai National Hospital (1968-1997) revealed many changes in the prevalent diseases: Tinea pedis and tinea unguium constantly increased during this period, and the ratio of the former associated with nail infection finally reached 30% of all tinea pedis patients. On the contrary, tinea corporis and cruris showed a remarkable decreasing tendency. Patient age distribution of each disease also showed distinctive changes, generally increasing in the older generation and decreasing in the younger. The number of patients with tinea pedis and unguium gradually increased among the middle and older generations, with the peak of the age-distribution curve shifting upward year after year. On the other hand, cases of tinea cruris among the younger generation were few in the latest years, and middle-age patients remained at a low number. In the first stage of this study the kinds of atiologic dermatophytes consisted of multiple species, but after middle period the isolation of Epidermaphyton floccosum decreased. Microsporum canis appeared first in 1976 but in the recent several years has completely disappeared. In the last few years of the period studied Trichophyton rubrum and Trichophyton mentagrophytes were the only isolates found from among all types of dermatophytoses. Infantile candidiasis remarkably increased in 1970-1975 but thereafter decreased rapidlly. Candidial intertrigo also increased in the same period but did not decrease as much thereafter and continued at the same intermediate level. The number of other types of candidiases were not greatly changed throughout the 30-year period. Malassezia infection also showed no remarkable changes, and only 20 cases of sporothrichosis were found. One case of the deep seated form of cutaneous aspergillosis was found, and this was also true of chromomycosis caused by Fonceaea pedrosoi.     

Repellency of essential oils to mosquitoes (Diptera: Culicidae).

The repellency of different concentrations (5, 10, 25, 50, 75, and 100%) and combinations of 5 essential oils (Bourbon geranium, cedarwood, clove, peppermint, and thyme) to Aedes aegypti (L.) and Anopheles albimanus Wiedemann when applied to human skin was determined in laboratory tests. Cedarwood oil failed to repel mosquitoes and only high concentrations of peppermint oil repelled Ae. aegypti. None of the oils tested prevented mosquito bite when used at the 5 or 10% concentration. Thyme and clove oils were the most effective mosquito repellents and provided 1 1/2 to 3 1/2 h of protection, depending on oil concentration. Clove oil (50%) combined with geranium oil (50%) or with thyme oil (50%) prevented biting by An. albimanus for 1 1/4 to 2 1/2 h. The potential for using essential oils as topical mosquito repellents may be limited by user acceptability; clove, thyme, and peppermint oils can be irritating to the skin, whereas both human subjects in this study judged the odor of clove and thyme oils unacceptable at concentrations > or = 25%.     

Fungicidal activities of commonly used disinfectants and antifungal pharmaceutical spray preparations against clinical strains of Aspergillus and Candida species.

The antifungal efficacy of commercial chemical disinfectants and pharmaceutical antifungal agents against medically important moulds and yeast species was investigated. Chlorine, phenol, sodium dodecyl sulfate and quaternary ammonium salts were the chemical disinfectants, and bifonazole and terbinafine were the antifungal pharmaceutical products tested against clinical isolates of Aspergillus and Candida species. Fungal inocula were obtained from conidial preparations of two A. ochraceus strains and yeast cells of C. albicans, C. krusei and C. parapsilosis. The antifungal activities were evaluated either by determining the kill rate in a cell suspension media at different contact periods, or by examining the viability and growth on plates sprayed with the active ingredient. Chlorine (1%) was the only disinfectant with the ability to cause a rapid inactivation of all five strains. Phenol (5%) was equally effective against Candida species; however, a number of A. ochraceus conidia were able to survive this treatment for up to 1 h. Benzalkonium chloride (0.5%) and cetrimide (0.5%) were also able to disinfect the three Candida species rapidly; however, these two quaternary ammonium compounds were relatively ineffective against A. ochraceus. In spray experiments, quaternary ammonium compounds had a fungicidal activity against Candida species and were fungistatic against A. ochraceus conidia. All five fungal strains were able to resist 0.5% sodium dodecyl sulfate, present either in the suspension solution or on the sprayed plate. Of the two pharmaceutical antifungal products tested, bifonazole (1%) were essentially ineffective against all five strains. Terbinafine (1%) had a fungicidal activity against A. ochraceus and C. parapsilosis. In suspension experiments, an exposure to 0.01% terbinafine required a contact period of 1 h for a complete inactivation of A. ochraceus conidia and an onset of fungicidal effect on C. parapsilosis yeast cells. Terbinafine was only moderately effective against C. albicans and was completely ineffective against C. krusei.     

Comparison of culture media for detecting methicillin resistance in Staphylococcus aureus and coagulase negative staphylococci.

The detection of methicillin resistance was examined in 51 strains of Staphylococcus aureus and 135 strains of coagulase negative staphylococci using Isosensitest, Diagnostic Sensitivity Test (DST), Mueller-Hinton (MH), Columbia, and Sensitest agars. MH agar with 5% added sodium chloride incubated at 35 degrees C was the most effective in detecting resistance in S aureus, and Columbia agar with 5% added sodium chloride incubated at 35 degrees C was most effective for coagulase negative staphylococci. For clinical purposes, a provisional report of sensitivity for S aureus could be issued after 18 hours; with coagulase negative staphylococci, only resistant strains could be reported at this time. For definitive results cultures must be examined after 40 hours of incubation.     

Monthly cycles of 1-week therapy with itraconazole for patients with Tinea pedis]

Monthly cycles of 1-week therapy with oral itraconazole at 200 mg daily for tinea pedis was assessed to determine its acceptability to patients. Thirty-four patients (17 men and 17 women) with intractable tinea pedis, with informed consent, took 200 mg of itraconazole once daily for one week over a month period until mycological studies showed negative results for up to 4 months. The overall mycological effectiveness was about 80% after this therapy. Information was also gathered on the influence of this therapy on the patients quality of life by questionnaires. Nineteen (70%) among the 27 patients who answered the questionnaire preferred this 1-week administration of itraconazole over a month-long period compared with continuous daily therapy. Twenty-two (81%) preferred this therapy over topical treatment. We recommend to this therapy be added for the treatment of intractable tinea pedis.     

Seven days of intermittent terbinafine 250 mg treatment in Tinea pedis]

Tinea pedis responds well to topical antifungal therapy, however, relapse of the disease is not uncommon. Long-term application of antifungals is usually necessary to control relapse. We conducted an open trial of a 7 day intermittent course of oral terbinafine treatment at 250 mg/day for plantar type and interdigital type of tinea pedis. Seventy-five patients of plantar type and 49 patients of interdigital tinea pedis were treated with a 7 day course of terbinafine 250 mg/day. Clinical assessments were made at baseline and every 4 weeks. Another 7 day course of the same amount of terbinafine were given depending on the clinical and the mycological response. Of the 75 plantar type tinea pedis with 8 patients excluded, 66 of the remaining 67 (98.5%) were evaluated as cured. Of the 49 interdigital tinea pedis (3 excluded), 43 of 46 patients (93.5%) cured. Relapse of the disease was observed in 4 of 51 patients at 1 year after treatment, 4 of 25 at 2 years, and 2 of 9 at 3 years in the plantar type, and in 4 of 30 at 1 year, 0 of 14 at 2 years, and 0 of 6 at 3 years in the interdigital tinea pedis group. Intermittent terbinafine therapy is thus effective in the treatment of tinea pedis.