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Dermatomycosis, including tinea pedis and onychomycosis, is frequently encountered in routine medical care in Japan. Identifying the risk factors for tinea pedis and onychomycosis development is important to encourage hospital visits by patients who may have these diseases but who are not undergoing any treatment. This approach may lead to the prevention of disease progression and the spread of infections to others. Risk factors for onychomycosis development have been reported both in and outside of Japan. However, most of the risk factors were identified based on a multicenter, questionnaire survey study and included evidence obtained from unclear or inconsistent diagnostic criteria for tinea pedis, onychomycosis, and identified risk factors. The current study analyzed the risk factors for developing tinea pedis and onychomycosis in real-world practice in Japan using a single-center, large-scale database that included the data of patients managed with consistent diagnostic criteria at the Podiatry Center of Juntendo University Hospital. A total of 2476 patients (1012 males, 1464 females) with a mean age of 63.4 years were included. Among these patients, 337 (13.6%) had tinea pedis and 346 (14.0%) had onychomycosis. A total of 259 patients (~ 75% of each patient population) had both diseases concomitantly. Multivariate logistic regression analysis adjusted for the possible risk factors of age (per 10 years), sex, diabetes, dialysis, visual impairment, ulcer history, lower-limb ischemia (LLI), and diabetic peripheral neuropathy (DPN) revealed that advanced age, male sex, diabetes, and LLI were independent risk factors for the development of tinea pedis. In addition, DPN was an independent risk factor for developing onychomycosis. We believe that these data are useful for identifying patients who are at high risk of developing tinea pedis and onychomycosis, which may result in disease prevention and suppression in real-world clinical practice in Japan., (© 2023 The Authors. The Journal of Dermatology published by John Wiley & Sons Australia, Ltd on behalf of Japanese Dermatological Association.)

This is a report of the results of the epidemiological survey on dermatomycoses conducted in 2021. A total of 9,442 patients with dermatomycosis were reported for one year. They include 8,151 (86.3%) with dermatophytosis, 796 (8.4%) with candidiasis, 484 (5.1%) with Malassezia infection, and 11 (0.1%) with deep cutaneous mycosis. In order, the most common types of dermatophytoses were tinea pedis (4,195 cases, 2,341 males and 1,854 females), tinea unguium (2,711 cases, 1,509 males and 1,202 females), tinea corporis (674 cases, 445 males and 229 females), tinea cruris (399 cases, 305 males and 94 females), tinea manus (125 cases, 78 males and 47 females), and tinea capitis (47 cases, 25 males and 22 females). The number of cases of tinea pedis and tinea unguium increased during the summer. A higher percentage of patients were aged 80 or older than in previous surveys. These findings may reflect the increasing percentage of elderly patients seen and the superannuation of the population. As in previous surveys, Trichophyton rubrum and Trichophyton interdigitale were the two most frequently isolated species of fungi causing dermatophytoses. Microsporum canis and Trichophyton tonsurans were the two species most often causing tinea capitis.Regarding cutaneous candidiasis, while candidal intertrigo was the most common in previous surveys, diaper candidiasis in the elderly was the most common in this survey. A background check revealed that this was because a facility included a semi-prophylactic approach to address diaper candidiasis occurring within the ward.Malassezia infections by Malassezia folliculitis clearly increased with each survey. The tendency of certain facilities with many reports of Malassezia folliculitis suggests that it is greatly affected by the presence of physicians familiar with the disease.

The prevalence of tinea pedis (also known as athlete's foot) in Japanese workers as well as contamination of their footwear by pathogenic filamentous fungi were investigated. Health checks by a dermatologist at a factory located in the Kanto region (Japan) led to a clinical and morphologic diagnosis of tinea pedis in 9 of 19 workers. Scales obtained from the feet and dust obtained from the protective footwear (safety shoes) worn daily in the factory were obtained from these nine subjects and tested using a mycological culture technique. Scales obtained from six of the nine subjects indicated pathogenic filamentous fungi, not only Trichophyton spp., but also Acremonium, which causes symptoms similar to tinea pedis or onychomycosis. Similarly, culture of the dust obtained from the safety shoes yielded pathogenic filamentous fungi in six of the nine subjects, and in four samples Trichophyton spp. was also identified. These findings suggest that cultivable Trichophyton spp. can be detected in approximately 40% of the safety shoes of workers with tinea pedis. The risk of reinfection by pathogenic filamentous fungi is likely increased by wearing dermatophyte-contaminated shoes.

We report here the results of the 2016 epidemiological survey of dermatomycosis in Japan. In total, 6,776 cases were analyzed as follows: dermatophytosis, 5,772 cases (85.2%); candidiasis, 757 cases (11.2%); Malassezia infection, 235 cases (3.5%); and other fungal infections, 11 cases (0.2%). In dermatophytosis, tinea pedis was the most frequent (3,314 cases: male, 1,705; female, 1,609), followed by tinea unguium (1,634 cases: male, 766; female, 868), tinea corporis (423 cases: male, 241; female, 182); tinea cruris (316 cases: male, 242; female, 74); tinea manuum (58 cases: male, 29; female, 29); tinea capitus, Celsus' kerion (26 cases: male, 19; female, 7); and tinea barbae (1 case: male, 1). The most frequent pathogen was Trichophyton rubrum. In candidiasis, candidal intertrigo was the most frequent (181 cases: male, 98; female, 83), followed by oral candidiasis (165 cases: male, 84; female, 81), genital candidiasis (119 cases: male, 45; female, 74), diaper candidiasis (113 cases: male, 49; female, 64), erosio interdigitalis (63 cases: male, 13; female, 50), onychomycosis (41 cases: male, 17; female, 24), onychia et paronychia (28 cases: male, 2; female, 26), and angular cheilitis (23 cases: male, 6; female, 17). Although the number of cases varied depending on the role of each cooperating medical institution in the area and on population composition, no significant differences in the frequencies of clinical types were observed.

The prevalence of skin mycoses in the elderly remains unclear. The proportion of people with skin eruptions who are positive for mycoses using direct microscopy is not known. The purpose of this study is to identify the prevalence of skin eruptions and skin mycoses (e.g. candidiasis and tinea) in the buttocks and feet, which are common sites of skin mycoses in residents of long-term care facilities. This multi-site cross-sectional study used visual inspection and direct microscopy to diagnose the type of skin eruption. Subjects were residents of facilities covered by long-term care insurance schemes in Japan. Of the 171 residents enrolled in this study, 72.5% had a skin eruption. Only 4.8% of participants had tinea in the buttocks; 2.4% had buttock candidiasis. In those with a nail abnormality, 58.3% of residents had tinea unguium. For tinea pedis, residents who had any form of interdigital or plantar region skin eruption, 22.5% and 31.4% of residents were positive, respectively. The prevalence of observed skin mycoses was: buttock candidiasis 1.8%; buttock tinea 3.5%; tinea unguium 56.2%; interdigital tinea pedis 20.5%; and plantar tinea pedis 22.5%. The very low proportion of residents with mycoses in the buttocks suggests that anti-inflammatory agents, such as steroids, should be used as first choice. Our observation that not all residents with skin eruptions on the feet had tinea, should remind clinicians to perform direct microscopy before initiating antifungal treatments., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

We conducted a retrospective cohort study on clinical and mycological features of tinea pedis and tinea unguium in psychiatric inpatients in Japan. Of the 317 inpatients (152 with schizophrenia and 165 with depression), 46.1% had tinea pedis and 23.7% had tinea unguium. Of those with tinea pedis, 48.6% also had tinea unguium. The most common clinical type of tinea pedis was the combination of interdigital type and hyperkeratotic type. The mean clinical score of tinea pedis was 5.9, and that of tinea unguium based on the Scoring Clinical Index for Onychomycosis (SCIO) was 15.8. The main causative species of tinea pedis were Trichophyton rubrum (68.4%) and T. mentagrophytes (26.3%). No statistically significant differences were observed in incidence rates of tinea pedis or tinea unguium between men and women or between patients with schizophrenia and those with depression. As for incidence rates by age, patients with depression showed a single peak for tinea pedis and / or tinea unguium in their 50's, while patients with schizophrenia exhibited twin peaks for tinea pedis and / or tinea unguium in their 50's and 70's. Both tinea pedis and tinea unguium tended to become more severe in patients with chronic schizophrenia. Our study suggests that schizophrenia and depression, like diabetes mellitus and HIV infections, should be regarded as risk factors for tinea pedis and tinea unguium.

Trichophyton rubrum var. raubitschekii is a rare anthropophilic dermatophyte isolated around the world from tinea corporis, tinea cruris, tinea pedis and tinea unguium. In this study, the isolation rate of T. rubrum var. raubitschekii was studied in 200 cases of tinea pedis and tinea unguium in Japan. The 200 clinical isolates were shown to be of downy type as their colonies on Sabouraud's dextrose agar were white to cream, suede-like to downy, with a yellow-brown to wine-red reverse, and they produced few macroconidia. The type strain of T. rubrum var. raubitschekii (CBS 100084) and one clinical isolate (KMU 8337; isolated at Kanazawa) of downy type tested positive for urease, but the reference strain of T. rubrum (CBS 392.58) and the remaining 199 clinical isolates tested negative. Further epidemiological investigations are required to study human cases of infection with the granular type of T. rubrum and T. rubrum var. raubitschekii in Japan., (© 2012 Japanese Dermatological Association.)

There has been no epidemiological survey of foot diseases in Japan. In this study we determined the prevalence of foot diseases, especially tinea pedis (TP) and tinea unguium (TU) in Japan. We conducted a randomized survey of outpatients who visited a dermatologist during the third week of May in 1999, 2000 and 2006. The most frequently reported condition was "fungal infection" in 8737 (40.0%) of 21 820 patients in 1999/2000, and 3848 (49.4%) of 7783 patients in 2006. The patients who visited a dermatologist for reasons other than superficial fungal infection but were diagnosed with TP or TU comprised 18.6% of the study population in 2000 and 24.1% in 2006. Of the patients with TP or TU, 63.2% used topical medication only. This survey showed that often patients are not aware of fungal infections and that their treatment is sometimes insufficient. Dermatologists should actively examine and treat patients with TP and TU.

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.

An epidemiological survey of dermatomycoses and the causative fungus flora of dermatophytoses in Japan for 2002 was made on a total number of 72,660 outpatients who visited 14 dermatological clinics throughout Japan. The results were as follows: 1) Dermatophytosis was the most prevalent cutaneous fungal infection (7,994 cases) seen in these clinics, followed by candidiasis (755 cases) and then Malassezia infections (220 cases). 2) Among dermatophytoses, tinea pedis was the most frequent (4,813 cases: male 2,439, female 2,374), then in decreasing order, tinea unguium (2,123 cases: male 1,093, female 1,030), tinea corporis (497 cases: male 281, female 216), tinea cruris (299 cases: male 249, female 50), tinea manuum (248 cases: male 144, female 104) and tinea capitis including kerion (14 cases, male 6, female 8). 3) Tinea pedis and tinea unguium are seen to increase in summer season, among the aged population and among males in each clinic. When compared to the previous surveys (1992 and 1997) by clinical form, t. unguium patients increased from 1.9% of total outpatients in 1992, to 2.0% in 1997, then to 2.9% in 2002. 4) As the causative dermatophyte species, Trichophyton rubrum was the most frequently isolated among all dermatophyte infections except tinea capitis. 5) T. rubrum was isolated from 63.3%(1,431/2,262) of tinea pedis lesions, followed by Trichophyton mentagrophytes (36.6%, 829/2,262), and also 88.8% (325/366) of t. corporis, 95.4% (185/194) of t. cruris and 85.6% (462/540) of t. unguium. 6) Cutaneous candidiasis was seen in 755 cases (1.0%) of 72,660 outpatients. Intertrigo (347 cases) was the most frequent clinical form, followed by erosio interdigitalis (103 cases) and diaper candidiasis (102 cases). It has a tendency to affect the aged being complicated with topical predisposing factors. 7) Cutaneous Malassezia infections and other superficial fungal infections are seen in 220 cases, without any characteristic features by gender or clinical form.

To research the current status of Trichophyton tonsurans infection in Tohoku District, I sent out a questionnaire to the main dermatology clinics in the Tohoku district. The results showed this infection was found first in spring, 2001 in Miyagi prefecture, and gradually spread from southern to northern districts; the total number of patients is now 162. The number in each prefecture is as follows: Yamagata; 88, Miyagi; 68, Akita; 4, Aomori; 2. In Iwate and Fukushima, however, no cases were reported. By age distribution high school students accounted for 117 (75%), elder patients for 29 (19%), lower age children only 10, and 6 cases were uncertain. Judo players accounted for 113 (70%) and wrestlers for 39 (24%). Family infections were found in two cases. Latent infections were found in several cases, and in one case the infection continued for 2.5 years without clinical symptoms. In my clinic 30 cases were observed beginning in 2001: high school boys accounted for 11, students of a professional school 14, college student 1, adults 3, and those involved in judo 27, wrestling 2 and mixed grappling sports 2. A family infection between a father and his daughter was found. According to the observations in our cases, this fungus easily invaded the hair roots from the early stage of infection, but was not noticed by common external clinical observations. Thus, microscopic examinations are necessary throughout the therapeutic process and to make certain of a complete cure. I think also necessary is the systemic administration of terbinafine or itraconazole for 4 or 6 weeks or more even for tinea corporis. Additionally, I emphasize that culture study is indispensable to confirm the infection by this fungi.

In this study, we investigated epidemiological and clinical aspects of dermatophyte foot infections among employees of one dairy product company located in Kanagawa prefecture in central Japan. Sixty-nine of 377 subjects were reported having "athlete's foot" in response to a simple questionnaire. A subsequent mycological examination revealed 41 untreated patients with tinea pedis and/or tinea unguium (89% of subjects examined) and the overall prevalence was estimated at 18%. Comparing severity scores of five clinical symptoms (itching, erythema, vesicles/pustules, erosion/maceration, and scales) between those untreated patients within the subjects and another group of patients who spontaneously attended dermatological clinics to treat tinea pedis, itching, erythema, and total score were significantly higher in the latter group.

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.

This study was conducted to show a higher prevalence of interdigital tinea pedis in athletes by comparing athletes and non-athletes, and to examine swimming pools as a route of infection. The subjects were 282 athletes, 137 non-athletes, and 140 students enrolled in a swimming class at the University of Tsukuba. This study included the taking of cotton-swab samples from the interdigital skin surfaces of both feet and cultures, microscopical examinations of scales collected from subjects with lesions, and questionnaires. There was a significant difference between athletes and non-athletes in the prevalence of the relevant pathogens, and a higher risk of infection was shown in athletes. The study also found that 63.6% of the swimming class students were carriers, and that 85.0% of their dermatophytes were Trichophyton mentagrophytes. In addition, dermatophytes were also isolated from the floors of the swimming pool and the public baths. The results of these controlled studies suggested that there was a significant risk of dermatophytosis in both athletes and non-athletes using the swimming pool.

We examined the relationship between prevalence and severity of tinea pedis and the length of service and the width of the spaces between the toes in 74 members of the Japanese Self-Defence Forces (SDF) undergoing special training. The subjects were divided according to the width of these spaces into: group I, wide; group II, fairly wide; and group III, closed. The severity of tinea pedis was determined by its duration and the extent of the lesions in the 49 subjects who had tinea pedis. The combined prevalence of tinea pedis and tinea unguium was 66%. There was a tendency for the prevalence to be higher in subjects who had served for 10 years or more in the SDF than in those with fewer than 10 years of service. Classified by the disposition of their toes, 10 subjects fell into group I, 34 into group II, and 30 into group III. The prevalence of 90% (27/30) in group III was significantly higher than in the other groups. A significant positive correlation was seen between length of SDF service and severity. Subjects with both a long service record and closed interdigital spaces showed both a high prevalence and marked severity.