Dermatophytes

Dermatophytes are keratinophilic fungi that are responsible for common infections such as tinea pedis, tinea capitis, and tinea unguium. Their wide prevalence is mainly due to the existence of large human and animal reservoirs coupled with their ease of transmission from one host to another and their high inherent resistance to harsh environmental conditions. Although normally noninvasive, dermatophytic infections may rarely disseminate, particularly in immunocompromised hosts. In spite of the multitude of options now available for the diagnosis and treatment of dermatophytic infection, certain forms, such tinea unguium, are often challenging to manage.     

Multicentric and localized tineas in immunocompromised patients

From the dermatological point of view, multifocal or multicentric tineas are widespread dermatophytic infections affecting two or more anatomical areas. In the immunosuppressed patient, these lesions are frequently atypical and the risk factors are not well established. The aims of this study were: to determine the risk factors associated to multicentric tinea in immunocompromised patients; to evaluate the immune response by trichophytin and candidin skin test, to determine the etiological agent and to quantify some serum interleukines. Thirty-six multicentric tinea and 37 localized tinea patients, both with immunocompromised factors, were included. By means of a questionnaire several risk factors were identified; the trichophytin and candidin skin test was evaluated after 48 hours. Mycological direct examination and culture were performed. The interleukins IL-2, IL-4, IL-10 and interferon gamma were quantified by ELISA. Statistical analysis was made by Chi-square, U Mann Whitney and logistic regression. In disseminated tinea patients a predominance of females (69%) versus localized tinea patients (30%) was observed. Prednisone, azathioprine and cyclophosphamide treatment was associated to multicentric tinea. Trichophytin was negative in all disseminated tinea patients and positive in only three localized tinea cases, candidin was positive in six and eight cases of multicentric and localized tinea respectively. Trichophyton rubrum was the most frequent etiological agent. No differences in interleukin concentrations were found. Female gender and some immunosuppressor treatments were associated with a high probability to develop multicentric tinea. In this study a defect in the cellular immune response was the possible explanation for the extensive reactions.     

New data on the epidemiology of Tinea cruris in Israel

Among 250 patients with tinea cruris (160 males, 90 females) lesions of both tinea pedis and tinea unguium were found in 221 and lesions of only tinea pedis in another 25. The four children were free of associated dermatophytic lesions. The predominant causative agent was T. rubrum, which was also found to be responsible for the hairy area invasion of the beard and pubis in 12 patients and for the widespread lesions of tinea corporis in 10 patients with lymphoma. None of these patients had noticed the discrete nail and foot involvement. It is therefore recommended that all patients with tinea cruris be subjected to careful examination of all possible mycotic foci, particularly the feet and nails.     

The mycoses of Oceania

A review of the mycoses of Oceania, defined as the Pacific islands of Melanesia, Micronesia and Polynesia, has revealed the occurrence of cutaneous, subcutaneous and systemic mycoses.Tinea versicolor is the most prevalent of the cutaneous mycotic infections. Dermatophyte infections are also common. The etiologic agents incriminated have beenEpidermophyton floccosum, Microsporum canis, members of theMicrosporum fulvum-gypseum complex,Trichophyton concentricum, T. mentagrophytes, T. rubrum, T. tonsurans andT. verrucosum. Only one case of tinea nigra has been reported and that was in Hawaii. Among the fungi that cause subcutaneous mycoses onlyAllescheria boydii, Nocardia brasiliensis, Madurella mycetomi andSporothrix schenckii have been encountered to date. Among the systemic mycoses, actinomycosis, cryptococcosis and histoplasmosis have been found to be present. The geographic distribution of these actinomycotic and mycotic infections is provided along with data on soil isolation records and histoplasmin sensitivity surveys.Paper presented at the Symposium on Microbiology, Canadian Medical Expedition to Easter Island, Montreal, April 26–28, 1971     

A study of 3891 cases of mycoses in the tropics.

4103 cases suspected of mycoses were analysed as to sex, age and site of disease and 3891 were proved cases. This group formed 50% of total mycoses or 13-93% of all dermatoses recorded in the Government General Hospital, Madras, during the period of study. There were 66-26% adult female, 27-6% adult male and 6-14% were below 13 years. Dermatophytoses were found in 73-5%; the other common diseases were tinea versicolor (17-68%) and candidiasis (12-43%). Multiple sites of involvement or more than 1 disease in the same individual were mostly observed. The incidence of piedra (0-1%) and deep mycoses (0-156%) was very low. Mycetoma was the common disease (5/6) in deep mycoses. In dermatophytoses, tinea corporis (49-71%) and tinea cruris (47-85%) commonest; tinea axillaris (3-42%), tinea capitis (1-72%) and tinea barbae (1-29%) were less common. The incidence of tinea manuum, tinea pedis and tinea unguium was similar (4-97%-6-38%). High temperature and humidity were related to the higher incidence of tinea corporis, tinea cruris and tinea versicolor. Mainly children suffered from tinea capitis. All other mycoses were commonly found in adults between 2nd and 3rd decades. In all mycoses but candidiasis, female predominated. Cutaneous candidiasis was mainly a problem of housewives. Among the dermatophytes Trichophyton violaceum was predominant (33-7%) followed by T. rubrum (32-6%). Trichophyton schoenleinii and M. gypseum were rarely isolated. From mycetoma, Madurella mycetomii, Nocardia braziliensis, N. asteroides and Actinomadura spp. were isolated. Demonstration of Cryptococcus laurentii in 1 case is reported in this area for the first time.     

Superficial infections caused by Microsporum canis in humans and animals

Dermatophytic infections caused by M. canis in humans and animals have a world wide distribution and they are zoonotic. The objective in this work was to know the frequency of M. canis infections in humans and pets. We studied our cases from January 1994 to December 2002. The human samples were obtained from a Dermatological Department in a General Hospital and we registered the next data: age, sex, job, and affected area. The animal samples were obtained from a mycological veterinary laboratory, and we registered the presence or absence of clinical lesions. A total of 46 clinical cases of M. canis infections were recorded, 26 female and 20 males: tinea capitis 21, tinea corporis 17, tinea pedis five, onychomycosis two, and only one case with tinea faciei. The 46 cases with positive culture yield 42 positive samples in KOH. The age range varied from 2 to 60 years. Among the animals, we studied 461 dogs and found six KOH positive (1%) samples and cultured 23 isolates (4.98%): 21 M. canis, one M. gypseum and one Trichophyton spp. From the 68 samples of cats, eight (11.76%) were positive to KOH, being 26 (38.23%) M. canis isolates. In M. canis infections in humans, the age rage was wide with predominance in women. In animals, M. canis isolates represented the most dermatophytic infection.     

浅部真菌病病原酵母菌构成调查及药敏研究

目的了解本地区浅部真菌病病原酵母菌感染菌种的构成及其耐药性特点,为临床提供病原学诊断和合理使用抗真菌药物的依据。方法采用改良沙氏培养基对1354份临床标本进行酵母菌培养和菌株分离,用科玛嘉念珠菌显色培养基和YBC鉴定卡对所分离的酵母菌进行鉴定,用ROSCO纸片扩散法检测分离菌株对6种常见抗真菌药物的耐药性。结果共分离出10种219株酵母菌,甲真菌病检出率最高(43.80%),其次是股癣(16.70%)、体癣(13.00%)、足癣(11.11%),手癣最低(9.40%)。其中白念珠菌为63.47%;近平滑念珠菌为17.81%;热带念珠菌为6.85%;季也蒙念珠菌为5.94%;无名念珠菌为2.28%,其他酵母菌为3.65%。219株酵母菌对特比萘芬(TBE)、伊曲康唑(ITC)、氟康唑(FLC)、制霉菌素(NYS)、咪康唑(MIC)和酮康唑(KTC)的敏感性分别为53.42%、87.21%、97.26%、100%、80.35%和100%,耐药性分别为20.55%、11.11%、2.28%、0.0、12.72%和0.0。结论本地区浅部真菌病酵母菌感染菌谱以白念珠菌为主,其次是近平滑念珠菌和热带念珠菌,体外药敏显示对制霉菌素、酮康唑和氟康唑有很好的敏感性,对特比萘芬、伊曲康唑和咪康唑产生了较高的耐药性。     

Trichophyton tonsurans scalp carriage among wrestlers in a national competition in Turkey

Trichophyton tonsurans tinea gladiatorum is an emerging epidemic among combat-sport athletes across the globe. In the present study, we investigated the prevalence of symptomatic and asymptomatic dermatophytic infections among wrestlers in the National Greco-Roman Championship in Turkey. In total, 194 wrestlers from 32 provinces and 72 clubs were examined for scalp, trunk, groin, and toe web dermatophytic infections. We also administered a questionnaire to obtain information on the participants' lifestyles, wrestling characteristics, and risk factors for dermatophytic infections. The hairbrush method was used for scalp and trunk sampling, whereas a cotton swab was used for groin, toe web, and mat sampling. Three wrestling mats in the gymnasium were surveyed for dermatophytes using the touch preparation method. A total of 17 (8.8%) wrestlers harbored dermatophytes, and 22 strains were isolated: 13 (59.1%) T. tonsurans and 9 (40.9%) T. rubrum. These isolates were found on the scalp (8), trunk (2), forearm (1), hand (1), groin (3), and feet (7). In addition, we recovered 8 dermatophyte strains from the 150 mat samples (5.3%): T. rubrum in 6 samples (75%) and T. tonsurans in two samples (25%). T. tonsurans was only recovered from 11 out of 194 (5.7%) wrestlers. Scalp carriage represents the predominant (72.7%) clinical picture of a T. tonsurans infection in these Greco-Roman wrestlers in Turkey.     

Epidemiology of Dermatophytoses in an Area South of Tehran,Iran

Dermatophyte infections have been considered to be a major public health problem in many parts of the world. The aim of this study was to identify the etiological and epidemiological factors of dermatophyte infections in an area south of Tehran. A total of 1254 patients suspected to have dermatophytic lesions were examined over a period of three years (1999-2001). Material collected from skin, hair, and nails was submitted to direct microscopic examination using KOH, cultured in Sabouraud dextrose agar and microscopically examined for colony morphology, in order to the identify the 169 dermatophytes isolated. The prevalence of dermatophytoses was 13.5% (95% CI: 11.7-15.5%). Their incidence was 10.6 per 100,000 person-years (95% CI: 8.5-13.2). Epiderophyton floccosum was the most frequent dermatophyte isolated (31.4%) followed by Trichophyton rubrum (18.3%), T. mentegrophytes (17.2%), T. violaceum (16.6%), Microsporum canis (6.5%), T. verrucosum (4.7%) and M. gypseum (4.1%). Epidermophytes floccosum was found to be the most common isolated dermatophyte in age groups 20-29 (30.2%). Tinea corporis (31.4%) was the most common type of infection, followed by tinea cruris (20.7%), tinea manuum (15.4%), tinea capitis (12.4%), tinea pedis (10.6%), tinea faciei (7.1%), and tinea unguium (2.4%). The frequency rate of all of the types of tinea was higher in males than in females. The anthrophilic species E. floccosum was the most common dermatophyte as a causative agent of tinea. The most prevalent fungal infection was tinea corporis caused by E. floccosum.     

Histopathological diagnosis of mycoses in veterinary pathology

Histopathological analysis demonstrates the morphology of the fungi and shows their relationship with tissue lesions, which is a valuable information in the diagnosis of veterinary mycoses, especially in superficial infections where reservoirs make difficult the diagnosis using other techniques. On the other hand, histopathological analysis should be complementary to other methods such as culture, immunohistochemistry, serology, PCR, etc. In this work, the most relevant histopathological features of some of the most common mycoses of domestic animals, some of which have zoonotic potential, are described and their differential diagnosis is discussed. To facilitate the discussion of the differential diagnoses, mycoses have been grouped by the sites of the infections and by the nature of the fungi (dimorphic and filamentous). Mycoses included in the study were 1) Superficial and deep infections: dermatophytosis, dermatophytic pseudomycetoma, eumycotic mycetoma, phaeohyphomycosis and malasezziasis. 2) Systemic mycoses: aspergillosis and zygomycosis. 3) Mycoses due to dimorphic fungi: candidiasis, cryptococcosis, blastomycosis, sporotrichosis, coccidioidomycosis and histoplasmosis. 4) Infections by algae and other fungi: protothecosis and pneumocystosis.     

Photodynamic Therapy in the Treatment of Superficial Mycoses: An Evidence-based Evaluation

Photodynamic therapy (PDT) is effective in the destruction of fungi. In order to evaluate the efficacy and safety of PDT for superficial mycoses, we performed an evidence-based review of published literature. Database of MEDLINE, EMBASE, and Cochrane Library was searched until March 2010. English-language articles evaluating the efficacy and safety of PDT for superficial mycoses were included. No randomized clinical trials were found. Seven reports described the antifungal effect of PDT against 63 superficial mycoses patients. Eight of 10 (80%) tinea cruris patients and 6 of 10 (60%) tinea pedis were led to mycological cure after 1–3 treatments. Unfortunately, only 4 (40%) tinea cruris patients and 3 (30%) tinea pedis had a persist healing at the 8-week follow-up. Six of the 9 (66.7%) foot-interdigital mycoses patients recovered clinically and microbiologically after 1 or 4 treatments. Only 2 patients (22.2%) had a persist healing at the 8-week follow-up. Eleven of 30 (36.6%) onychomycosis patients were cure for 18 months after treatment, and 3 onychomycosis patients were all cure in other 2 reports. The therapeutic effect of PDT for one pityriasis versicolor patients was well. Overall tolerability of PDT was good. Therefore, it is unclear what PDT’s place for superficial mycoses will be. Further clinical trials are needed to evaluate the efficacy of PDT to treat superficial mycoses. It is also important to optimize treatment protocols in order to cope with recurrence.     

Pseudomycetoma for microsporum canis: report of a case diagnosed by fine needle aspiration biopsy

BACKGROUND: Fine needle aspiration biopsy (FNAB) of the skin is useful in subcutaneous lesions. Dermatophytes are almost exclusively superficial cutaneous mycoses and constitute 70-80% of all mycoses and 5% of dermatologic consultations. Inflammatory and invasive forms, as well as infections that remain in chronic forms or persist in spite of treatment, are more frequent in immunocompromised individuals. The clinicalpresentations of these invasive cases are dermatopbytic granulomas (granuloma of Wilson-Majocchi and pseudomycetoma) or Hadida's disease. CASE: A 17-year-old male with an 8-year history of tinea capitis and multiple kerion lesions in the occipital region, left foot and right elbow resistant to conventional treatment was diagnosed by KOH tests and cultures as Microsporum canis. Two months before consultation he noticed the slow growth of a subcutaneous nodule in the base of the neck. FNAB of the neck nodule was performed. The diagnosis of pseudomycetoma by Microsporum canis was made. CONCLUSION: We report a case of pseudomycetoma caused by Microsporum canis, with the diagnosis made by FNAB. This case appears to be the first one diagnosed by this method in a human.     

Fungal infection of the feet in soccer players and non-athlete individuals

This study was conducted to evaluate the occurrence of mycoses affecting the feet of soccer players and to compare this results with those in non-athlete individuals of the same age and sex. Initial evaluation consisted of a dermatological examination of the foot in 22 Chinese athletes, 83 Brazilian athletes and 24 Brazilian non-athletes. Scales of plantar skin, interdigital and subungual areas of the foot were collected for mycological examination (direct and culture). Nail clippings were obtained for histopathologic analysis. Tinea pedis was diagnosed more frequently among the non-athlete individuals. None of the Chinese athletes had tinea pedis alone. However, in this group onychomycosis was frequently higher when compared to the other groups. The fungal microbiota comprised Trichophyton rubrum (40%), Trichophyton mentagrophytes (36.4%) and Candida spp (20%). Candida spp was isolated only from Brazilian athletes. Results obtained with KOH wet mounts agreed with the results obtained in culture and with histopathologic examinations (50.5% vs 40.9%). The frequency of tinea pedis among soccer players was lower than the other groups in this study, possibly due to health education and professional feet care.     

Tinea capitis due to Trichophyton tonsurans; incidence,diagnosis and epidemiology in the San Francisco Bay Region

Eighty-five cases of tinea capitis due to T. tonsurans were observed in the San Francisco Bay area during the five years 1950-54. This disease, unlike the common microsporum infections, sometimes affects adults and adolescents. Hairs infected with T. tonsurans do not fluoresce under the Wood's light. Diagnosis is a laboratory procedure in which the fungus is isolated from the hair. There are three clinical varieties of the disease. The course is prolonged and treatment is unsatisfactory. The disease apparently has spread from Mexico, through the Southwest and Southern California. Control is difficult.     

Use of terbinafine in rare and refractory mycoses.

Terbinafine is the only systemic allylamine antifungal currently available. Its mechanism of action is unique and sets it apart from other agents. Although it is primarily used for dermatophyte infections, such as onychomycosis and tinea pedis, terbinafine has broad in vitro activity against a variety of non-dermatophyte fungal pathogens, including Candida spp. and many molds. In addition, synergistic activity is noted with other antifungals, notably triazoles. Multiple case reports exist of its use for unusual and refractory fungal infections, but no systematic review is available. We review the current literature with regard to in vitro data and clinical experience with terbinafine in the treatment of rare and refractory mycoses.     

阴囊皮肤癣菌病患者临床及 真菌学分析

目的探讨阴囊皮肤癣菌病患者的致病菌、临床特征、易感因素及治疗转归等相关因素。方法回顾性分析2007-2017年广州市中山大学附属第三医院经真菌学检查确诊的24例阴囊癣病例,分析患者一般资料、临床特征、发病相关因素、合并其他部位浅部真菌病情况、病原菌及治疗转归等情况。结果 24例阴囊癣患者均为青少年,平均年龄19.6岁,平均病程2.9个月。患者分离皮肤癣菌24株,其中石膏样小孢子菌15株(62.50%)、红色毛癣菌7株(29.17%)和絮状表皮癣菌2株(8.33%)。石膏样小孢子菌主要引起阴囊单纯性感染,临床表现为特征性的白色伪膜样斑片,而红色毛癣菌多引起阴囊及其他部位皮肤癣菌病。结论阴囊癣多见于青少年,石膏样小孢子菌为主要病原菌,其临床表现具有一定特征性。     

Las micosis en Venezuela: casuística de los Grupos de Trabajo en Micología (1984-2010)

BackgroundIn 1984 the Venezuelan Work Groups in Mycology (VWGM) were created introducing an innovative approach to the study of the mycoses in Venezuela.AimTo study the occurrence of the mycoses in Venezuela.MethodsReview the reported cases of mycoses by the newsletter Boletín Informativo Las Micosis en Venezuela (VWGM) from 1984 to 2010.ResultsThe data collected showed 36,968 reported cases of superficial mycoses, 1,989 of deep systemic cases, and 822 of localized mycoses. Pityriasis dermatophytosis was the most common superficial infection, and paracoccidioidomycosis and histoplasmosis the most frequent deep systemic infection. Chromoblastomycosis was the most frequently diagnosed subcutaneous infection. The data provided showed the distribution by geographical area for each of the fungal infections studied, which may help to establish the endemic areas.DiscussionSuperficial mycosis is a public health problem due to its high morbidity and is probably responsible for some of the outbreaks in high-risk groups. Paracoccidioidomycosis and histoplasmosis were reported more often, which agrees with earlier reports prior to the formation of the VWGM. Cases of sporotrichosis and chromoblastomycosis in Venezuela can be considered unique due to the high number of cases. This study highlights the contribution of the VWGM to the behavior of the mycoses in Venezuela, its incidence, prevalence, and the recognition of these infections as a problem of public health importance. The VWGM should keep working in this endeavor, not only reporting new cases, but also unifying the clinical and epidemiological criteria, in order to properly monitor the evolving epidemiological changes reported in these types of infections.     

濮阳市部分浅部真菌病中癣菌和念珠菌混合感染的分析

目的了解濮阳地区部分浅部真菌病中两种及两种以上真菌混合感染的情况。方法对临床确诊为浅部真菌病的患者456例,取标本行10%KOH直接镜检、真菌培养及菌种鉴定。登记确诊患者相关临床资料,分析其中混合感染的发病特点。结果确诊皮肤癣菌和念珠菌混合感染病例36例,分离率为7.89%,多见于股部(58.33%)和足部(27.78%);分离菌株72株,皮肤癣菌中以红色毛癣菌为主(75.00%),念珠菌中以非白念珠菌为主(72.22%)。结论濮阳地区部分浅部真菌病中混合感染主要为皮肤癣菌和念珠菌的混合感染,多见于股部和足部;致病菌以红色毛癣菌和非白念珠菌为主。     

A review of medical mycology in Colombia,South America

Summary A review of the mycotic cases diagnosed in Colombia is presented. The deep mycoses have been all observed, with the exception of North American Blastomycosis. The commonest entities are South American Blastomycosis, Sporotrichosis and Chromoblastomycosis.Among the superficial mycoses, tinea capitis and corporis were noticed most frequently.Microsporon canis was isolated in most instances. Some other superficial mycoses, as Pityriasis versicolor and Piedra were also observed.National references pertaining to the subject are included.

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Sumpaio Se presenta una revisión de los cases colombianos de Micosis. Todos los tipos de micosis profundas, con excepción de la Blastomicosis Norteamericana, han sido observados en nuestro territorio. Como entidades más frecuentes podemos anotar la Blastomicosis Suramericana, la Esporotricosis y la Cromoblastomicosis.Entre las micosis superficiales se anota una mayor incidencia de tinea capitis y corporis, siendo elMicrosporon canis el agente etiológico aislado más frecuentemente. Se reporta igualmente la incidencia de otras formas superficiales, tales como, la pitiriasis versicolor y la piedra del cabello.Se incluye la literatura nacional obtenida sobre el tema.

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Part of this work was presented as a thesis for the degree of Doctor in Medicine to the Faculty of Medicine, University of Antioquia by one of us (Sánchez-Arbelaéz J.) in 1957.     

Non-dermatophyte Dermatoses Mimicking Dermatophytoses in Humans

Human dermatophytic cutaneous infections usually present as single or multiple slowly progressing annular erythemato-squamous lesions with a tendency to central healing on the hairless skin. In the intertriginous regions (feet, inguinal, axillar, submammary), dermatophytic colonisations and infections manifest as whitish, slightly hyperkeratotic, pruritic and sometimes fissurated lesions. On the scalp, dermatophytic infections commonly lead to single or multiple more or less inflammatory and alopecic lesions. On the plantar and palmar aspects of the feet and hand, dermatophytosis presents as an eczema-like chronic dermatosis. Abscess-like lesions may occur due to zoophilic dermatomycosis. Dermatophytic infections of the nails reveal ill-defined whitish-yellowish colorations of the distal end or the lateral aspects of the nails, sometimes combined with partial nail embrittlement or even complete destruction. Despite the ubiquity of dermatophytic skin infections and their usually highly typical clinical features, a differential diagnosis has to be considered, in particular when treatment is not efficient or when treatment resistance occurs. This review presents the differential diagnosis in terms of frequency as well as the diagnostic methods permitting the distinction of annular, intertriginous, alopecic, palmoplantar, abscess-like and onychodystrophic lesions.