Dermatophyte and non-dermatophyte onychomycosis in Singapore

Global prevalence of onychomycosis in general and special populations: An updated perspective

BACKGROUND

Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge.

OBJECTIVE

To provide an updated estimate on the prevalence of toenail onychomycosis.

METHODS

We conducted a literature search using PubMed, Embase and Web of Science. Studies reporting mycology-confirmed diagnoses were included and stratified into (a) populations-based studies, and studies that included (b) clinically un-suspected and (c) clinically suspected patients.

RESULTS

A total of 108 studies were included. Based on studies that examined clinically un-suspected patients (i.e., with or without clinical features suggestive of onychomycosis), the pooled prevalence rate of toenail onychomycosis caused by dermatophytes was 4% (95% CI: 3-5) among the general population; special populations with a heightened risk include knee osteoarthritis patients (RR: 14.6 [95% CI: 13.0-16.5]), chronic venous disease patients (RR: 5.6 [95% CI: 3.7-8.1]), renal transplant patients (RR: 4.7 [95% CI: 3.3-6.5]), geriatric patients (RR: 4.7 [95% CI: 4.4-4.9]), HIV-positive patients (RR: 3.7 [95% CI: 2.9-4.7]), lupus erythematosus patients (RR: 3.1 [95% CI: 1.2-6.3]), diabetic patients (RR: 2.8 [95% CI: 2.4-3.3]) and hemodialysis patients (RR: 2.8 [95% CI: 1.9-4.0]). The prevalence of onychomycosis in clinically suspected patients was significantly higher likely due to sampling bias. A high degree of variability was found in a limited number of population-based studies indicating that certain pockets of the population may be more predisposed to onychomycosis. The diagnosis of non-dermatophyte mould onychomycosis requires repeat sampling to rule out contaminants or commensal organisms; a significant difference was found between studies that performed single sampling versus repeat sampling. The advent of PCR diagnosis results in improved detection rates for dermatophytes compared to culture.

CONCLUSION

Onychomycosis is an underrecognized healthcare burden. Further population-based studies using standardized PCR methods are warranted.

Onychomycosis due to Fusarium species in different continents, literature review on diagnosis and treatment

Fusarium species are an emerging cause of onychomycosis, and the number of cases has dramatically increased in recent decades worldwide. This review presents an overview of the onychomycosis cases caused by Fusarium species and diagnosis and treatment that have been reported in the literature. The most common causative agent of onychomycosis is F. solani species complex, which accounts for 11.68% of the cases of Fusarium onychomycosis, followed by the F. oxysporum species complex (164 out of 1669), which is accounted for 9.83% of the total. F. fujikuroi species complex (42 out of 1669) and F. dimerum species complex (7 out of 1669) are responsible for 2.52% and 0.42 cases, respectively. Fusarium nail infections were reported in patients aged range 1-98, accounting for 5.55% (1669 out of 30082) of all cases. Asia has the highest species diversity of Fusarium onychomycosis (31.51%). South America accounts for 21.09%, and the most common causative agent is F. solani (19.32%), followed by F. oxysporum species complex (15.63%). Europe accounts for 4.90% of cases caused by F. oxysporum, followed by F. solani. Africa accounts for 23.87% of the cases due to the F. solani species complex, followed by F. oxysporum and F. fujikuroi. Distal and lateral subungual onychomycosis was the most common clinical symptom accounting for 58.7% (135 out of 230) of the cases. Data analysis relieved that terbinafine and itraconazole are active treatments for Fusarium onychomycosis. For a definitive diagnosis, combining of direct examination, culture and sequencing of the elongation factor of translation 1α are recommended. Accurate identification of the causative agents of onychomycosis due to Fusarium species and antifungal susceptibility testing is essential in patient management.

Superficial mycoses, a matter of concern: Global and Indian scenario-an updated analysis

Superficial mycoses of skin, nails and hair are among the common fungal infections. They are caused by dermatophytes, non-dermatophyte moulds, yeasts and yeast-like fungi. Such fungal infections are widespread all over the world and are predominant in tropical as well as subtropical regions. Environmental factors, such as warm, humid and pitiable hygienic conditions, are conducive for their growth and proliferation. Although it does not cause mortality, it is known to be associated with excessive morbidity which may be psychological or physical. This affects the quality of life of the infected individuals which leads to a negative impact on their occupational, emotional and social status. Such infections are increasing on a global scale and, therefore, are of serious concern worldwide. This review article covers the global and Indian scenario of superficial mycoses taking into account the historical background, aetiological agents, prevalence, cultural and environmental factors, risk factors, pathogenesis and hygienic practices for the prevention of superficial mycoses.

Diversity of phenotypically non-dermatophyte, non-Aspergillus filamentous fungi causing nail infections: importance of accurate identification and antifungal susceptibility testing

Onychomycosis is most commonly caused by dermatophytes. In this study, we examined the spectrum of phenotypically non-dermatophyte and non-Aspergillus fungal isolates recovered over a 10-year period from nails of patients with onychomycosis in Hong Kong. A total of 24 non-duplicated isolates recovered from 24 patients were included. The median age of the patients was 51 years, and two-thirds of them were males. One-third and two-thirds had finger and toe nail infections respectively. Among these 24 nail isolates, 17 were confidently identified as 13 different known fungal species, using a polyphasic approach. These 13 species belonged to 11 genera and ≥9 families. For the remaining seven isolates, multilocus sequencing did not reveal their definite species identities. These seven potentially novel species belonged to four different known and three potentially novel genera of seven families. 33.3%, 41.7% and 95.8% of the 24 fungal isolates possessed minimum inhibitory concentrations of >1 µg/mL to terbinafine, itraconazole and fluconazole, respectively, the first line treatment of onychomycosis. A high diversity of moulds was associated with onychomycosis. A significant proportion of the isolates were potentially novel fungal species. To guide proper treatment, molecular identification and antifungal susceptibility testing should be performed for these uncommonly isolated fungal species.

A Review of Onychomycosis Due to Aspergillus Species

Aspergillus spp. are emerging causative agents of non-dermatophyte mould onychomycosis (NDMO). New Aspergillus spp. have recently been described to cause nail infections. The following criteria are required to diagnose onychomycosis due to Aspergillus spp.: (1) positive direct microscopy and (2) repeated culture or molecular detection of Aspergillus spp., provided no dermatophyte was isolated. A review of 42 epidemiological studies showed that onychomycosis due to Aspergillus spp. varies between < 1 and 35% of all cases of onychomycosis in the general population and higher among diabetic populations accounting for up to 71% and the elderly; it is very uncommon among children and adolescence. Aspergillus spp. constitutes 7.7-100% of the proportion of NDMO. The toenails are involved 25 times more frequently than fingernails. A. flavus, A. terreus and A. niger are the most common aetiologic species; other rare and emerging species described include A. tubingensis, A. sydowii, A. alliaceus, A. candidus, A. versicolor, A. unguis, A. persii, A. sclerotiorum, A. uvarum, A. melleus, A. tamarii and A. nomius. The clinical presentation of onychomycosis due to Aspergillus spp. is non-specific but commonly distal-lateral pattern of onychomycosis. A negative culture with a positive KOH may point to a NDM including Aspergillus spp., as the causative agent of onychomycosis. Treatment consists of systemic therapy with terbinafine or itraconazole.

Tinea unguium onychomycosis caused by dermatophytes: a ten-year (2005-2014) retrospective study in a tertiary hospital in Singapore

INTRODUCTION

Tinea unguium is a common nail infection. We conducted a retrospective ten-year study of the patient demographics and species distribution of dermatophytes causing tinea unguium in a tertiary hospital from Singapore.

METHODS

Results of fungal nail cultures were retrieved from our hospital's microbiology department. Samples from nail scrapings and clippings were inoculated onto agar plates (Sabouraud dextrose agar with chloramphenicol and Mycosel agar). Nail specimens that grew dermatophytes were included in the study.

RESULTS

Overall, 229 (male: n = 164, 71.6%; female: n = 65, 28.4%) nail specimens grew dermatophytes. Mean patient age was 58 (range 18-93) years. A majority of specimens came from patients aged over 50 years (n = 162, 70.7%) and 60-79 years (n = 100, 43.7%). Ethnically, 160 (69.9%) patients were Chinese, 36 (15.7%) Indian, 18 (7.9%) Malay and 15 (6.6%) of other ethnicities. Among dermatophytes isolated were Trichophyton rubrum (n = 93, 40.6%), Trichophyton mentagrophytes (n = 60, 26.2%), unidentified Trichophyton spp. (n = 57, 24.9%), Trichophyton tonsurans (n = 10, 4.4%), Epidermophyton floccosum (n = 5, 2.2%), Trichophyton verrucosum (n = 2, 0.9%), Trichophyton soudanense (n = 1, 0.4%) and Trichophyton violaceum (n = 1, 0.4%).

CONCLUSION

A majority of isolates were from elderly patients. Compared to Singapore's general population, patients of Indian and other ethnicities were over-represented for tinea unguium when compared to Chinese and Malay patients. Trichophyton rubrum was the most common dermatophyte isolated, while Trichophyton verrucosum, Trichophyton violaceum and Trichophyton soudanense were rare causes of tinea unguium.

Epidemiological survey of dermatophytosis in Damascus, Syria, from 2008 to 2016

Background and Purpose:

It is important to follow annually the probable changes in distribution pattern of dermatophytosis and its etiological agents in different communities. In this study, we determined the prevalence of dermatophytosis and its causative agents in Damascus, Syria, between 2008 and 2016.

Materials and Methods:

A total of 4080 outpatients who visited the dermatological clinics in Damascus, were evaluated. The specimens were collected from clinically suspected tinea. The patients were referred to our laboratory for direct examination by 30 %KOH. Some of the specimens were cultured on Sabouraud Dextrose Agar for fungal identification.

Results:

Out of the 4080 cases, 1138 cases were positive in direct examination(%27.89) , including Tinea pedis (%46.98), followed by tinea capitis(%39.79) , tinea corporis (%25.38), toenail onychomycosi (%20.33), tinea manuum (%16.06), and fingernail onychomycosis .(%15.22) Tinea pedis and toenail onychomycosis were more common in summer %41.19) and %25.78 respectively .(Trichophytic rubrum was the most prevalent fungal pathogen, especially in toenail onychomycosis.

Conclusion:

Dermatophytosis is highly prevalent in Syria. This study provides valuable data for differential diagnosis of dermatophytosis.

Genotyping and In Vitro Antifungal Susceptibility Testing of Fusarium Isolates from Onychomycosis in India

Onychomycosis refers to fungal infection of the nail and is commonly caused by dermatophytes, while yeasts and non-dermatophytic molds (NDM) are increasingly recognized as pathogens in nail infections. The present study was done to delineate molecular epidemiology of Fusarium onychomycosis in India. Five hundred nail samples of Indian patients clinically suspected of onychomycosis were subjected to direct microscopy and fungal culture. Representative Fusarium isolates were further identified to species level by multi-locus sequencing for internal transcribed spacer, translation elongation factor 1 alpha (tef1-α) and RNA polymerase II subunit (rpb2) regions (primer pairs: ITS1/ITS4, EF1/EF2, 5f2/7cr, respectively). These representative strains were also tested for in vitro antifungal susceptibility by the broth microdilution method. Members of the genus Fusarium proved to be the most common NDM responsible for onychomycosis. The Fusarium spp. responsible for onychomycosis belonged to the Fusarium solani species complex (F. keratoplasticum and F. falciforme) and Fusarium fujikuroi species complex (F. proliferatum, F. acutatum and F. sacchari). Antifungal susceptibility results indicated that amphotericin B was the most effective antifungal across all isolates (MIC ranging 0.5-2 mg/L), followed by voriconazole (MIC ranging 1-8 µg/ml). However, a large variation was shown in susceptibility to posaconazole (MIC ranging 0.5 to >16 µg/ml). To conclude, we identified different Fusarium spp. responsible for onychomycosis in India with variation within species in susceptibility to antifungal agents, showing that fusariosis requires correct and prompt diagnosis as well as antifungal susceptibility testing.

Spectrum of Fusarium infections in tropical dermatology evidenced by multilocus sequencing typing diagnostics

Fusarium species are emerging causative agents of superficial, cutaneous and systemic human infections. In a study of the prevalence and genetic diversity of 464 fungal isolates from a dermatological ward in Thailand, 44 strains (9.5%) proved to belong to the genus Fusarium. Species identification was based on sequencing a portion of translation elongation factor 1-alpha (tef1-α), rDNA internal transcribed spacer and RNA-dependent polymerase subunit II (rpb2). Our results revealed that 37 isolates (84%) belonged to the Fusarium solani species complex (FSSC), one strain matched with Fusarium oxysporum (FOSC) complex 33, while six others belonged to the Fusarium incarnatum-equiseti species complex. Within the FSSC two predominant clusters represented Fusarium falciforme and recently described F. keratoplasticum. No gender differences in susceptibility to Fusarium were noted, but infections on the right side of the body prevailed. Eighty-nine per cent of the Fusarium isolates were involved in onychomycosis, while the remaining ones caused paronychia or severe tinea pedis. Comparing literature data, superficial infections by FSSC appear to be prevalent in Asia and Latin America, whereas FOSC is more common in Europe. The available data suggest that Fusarium is a common opportunistic human pathogens in tropical areas and has significant genetic variation worldwide.

A 10-Year Study of Dermatophytoses in Isfahan, Iran

Dermatophyte infections are very common worldwide and their epidemiological characteristics vary according to the geographical region and have altered in the last decades. The aim of the present investigation was to determine the diversity of causative agents of dermatophytoses and describe the epidemiological condition of infection in Isfahan, Iran, between 2003 and 2012. Specimens were collected from hair, nail, and skin and were examined by conventional methods such as direct microscopy, culture on sabouraud dextrose agar with chloramphenicol and cycloheximide (Mycosel agar) and sabouraud glucose agar, Trichophyton agars, growth on rice grains, urease test, and hair perforation test. Of 13,469 clinically suspected cases, 11.5% were affected with dermatophytoses. Tinea capitis was the most frequent form of infection (52.7%), followed by tinea corporis (24%), tinea pedis (8.9%). Trichophyton verrucosum was the most prevalent causative agent (40.6%), followed by T. mentagrophytes var. interdigitale (17.6%), Epidermophyton floccosum (13%), T. violaceum (12%), T. rubrum (4.1%). Age range of patients was between 1 and 80 years. Housewives were the most patients in our study. The study emphasizes importance of epidemiological surveys of dermatophyte species for the better management of infection.

Isolation of dermatophytes (and other fungi) from human nail and skin dust produced by podiatric medical treatments in Australia

BACKGROUND

Podiatric physicians routinely use electric drills for the treatment of nail and skin conditions. The grinding process produces human nail and skin dust that is generally vacuumed into bags in the grinding unit. Many of the nails are thought to be mycotic, particularly because they are obtained from patients with symptoms of dermatophyte infections. Currently, there is limited information available on the detection of fungi from nail dust samples. Herein, we attempt to address this situation and outline some of the difficulties that pathology laboratories face in isolating and identifying dermatophytes from nail samples.

METHODS

Fifty nail dust bags from podiatric medical clinics across all of the states and territories of Australia were collected and analyzed. Samples from the bags were inoculated onto primary isolation media. Fungal colonies that grew were then inoculated onto potato dextrose agar for identification using standard morphological (macroscopic and microscopic) features.

RESULTS

One hundred fifty-one colonies of dermatophytes were identified from 43 of the 50 samples. In addition 471 nondermatophyte molds were isolated, along with some yeasts and bacteria.

CONCLUSIONS

The most common dermatophytes isolated were from the Trichophyton mentagrophytes/interdigitale complexes. Trichophyton rubrum, Trichophyton tonsurans, Trichophyton soudanense, and Epidermophyton floccosum were also isolated. An unidentified group of dermatophytes was also present. The three most common genera of nondermatophyte molds were Aspergillus, Penicillium, and Scopulariopsis, all of which have been implicated in onychomycosis and more general disease. The presence of viable fungal pathogens in the dust could potentially pose a health problem to podiatric physicians.

Etiology of foot mycosis and onychomycosis

The article presents data from Russian and foreign sources related to the etiology of foot mycosis and onychomycosis. In spite of the substantial spread of data by countries and regions of the world, dermatophytes play a leading part in the etiology of foot mycosis and onychomycosis, and Trichophyton rubrum is found in most studies in more than one half of all cases. Yeast-like fungi of the Candida genus as well as mold fungi belong to less frequent pathogens of foot mycosis. However, they play a greater role in countries with hot and humid climate such as Brazil, Indonesia, Columbia and India. These data are important for the determination of organizational measures aimed at the early diagnostics of patients, timely treatment and implementation of anti-epidemic and disinfectant measures.

Nondermatophytic moulds as a causative agent of onychomycosis in tehran

Background:

In the last few years the number of cases of nondermatophytic onychomycosis has greatly increased.

Aim:

To evaluate the incidence, the clinic characteristics, and predisposing factors of nondermatophytic onychomycosis.

Materials and Methods:

All collected specimens were analyzed by direct microscopy and culture. Microscopic examination of these specimens was carried out in potassium hydroxide solution (20%) with dimethyl sulfoxide (4%). These specimens were cultured on sabouraud's glucose agar with chloramphenicol and sabouraud's glucose agar with chloramphenicol and cycloheximide. Cultures were incubated at 25°C for up to 28 days and checked twice weekly for growth.

Results:

Nondermatophytic onychomycosis were 11.5% of all onychomycosis. We found that Aspergillus spp. were the more responsible etiologic agents of nondermatophytic onychomycosis, resulting in a total of 28 patients (59.6%). In our study other causative agents were Acremonium spp. (17%), Fusarium spp. (12.7%), Geotrichum spp. (4.2%), Trichosporun spp., (4.2%) and Scopulariopsis spp (2.1%). In our patients moulds onychomycosis developed mainly in toenails (74.5%).

Conclusion:

Knowing the exact pathogen is important and has implications in therapy and prognosis.

Isolation of Fusarium sp. from a claw of a dog with onychomycosis

An 8-year-old male Golden Retriever had lameness and claw abnormality in the second digit of the left forelimb. Radiography revealed osteomyelitis in the distal phalanx bone of the affected limb. Microscopic examination of the claw revealed numerous hyphae in the claw matrix. Fungal DNA fragments coding the ribosomal internal transcribed spacer region (ITS) were detected from the claw matrix as well as fungal colonies of the clinical isolates by PCR. Nucleotide sequencing revealed that the amplicons shared > 99% homology with Fusarium sp. Therapy including oral itraconazole resulted in regrowth of a new claw, in which no hyphae were detected. To the authors' knowledge, this is the first case report of canine onychomycosis in which Fusarium sp. was isolated from the affected claw.

Other fungi causing onychomycosis

Nondermatophyte onychomycosis account for 2% to 12% of all nail fungal infections and can be caused by a wide range of fungi, mainly Scopulariopsis brevicaulis, Aspergillus versicolor, A. flavus, A. niger, A. fumigatus, Fusarium solani, F. oxysporum and Scytalidium spp. Among the predisposing factors are footwear, hyperhidrosis, local trauma, peripheral circulatory disease, and immunosuppression. These nondermatophyte fungi lack the keratinolytic capacity of dermatophytes, but they still can infect alone or in combination with the latter. Because most are considered laboratory contaminants, special criteria have been created for the correct diagnosis of nondermatophyte onychomycosis. The etiologic agent does not determine the clinical pattern of nail invasion, but superficial onychomycosis is frequently observed; leukonychia and melanonychia can also be clinical manifestations.

Fusarium spp. as agents of onychomycosis in immunocompetent hosts

BACKGROUND

Fusarium spp. are nondermatophyte filamentous fungi, frequently reported as an etiologic agent of opportunistic infections in humans; however, their involvement in the etiology of cutaneous lesions is still debatable, especially in immunocompetent patients, where they are often considered as contaminant fungi.

OBJECTIVE

The aims of this study were to report the high prevalence of onychomycosis by Fusarium spp. in immunocompetent patients in the region of Maringá, Paraná, Brazil, to establish clinical and laboratory criteria for this genus as a causal agent of onychomycosis, and to determine the susceptibility profile to the systemic antifungal drugs most frequently used in Brazil (itraconazole, ketoconazole, terbinafine, and amphotericin B).

METHODS

The fungi were isolated and identified through the classical method, and sensitivity tests were carried out according to the National Committee for Clinical Laboratory Standards (NCCLS) M38-A protocol.

RESULTS

Of the 360 confirmed cases of onychomycosis, 27 (7.5%) were attributed to the genus Fusarium, and F. oxysporum was the most commonly isolated species. Nail lesions with paronychia and pain, combined with direct suggestive microscopy and a high concentration of microorganisms, were predictive of onychomycosis by Fusarium spp. The minimum inhibitory concentration was high for itraconazole, ketoconazole, and terbinafine, but low for amphotericin B.

CONCLUSIONS

It is recommended that more attention should be given to the interpretation and identification of species of the Fusarium genus in superficial clinical samples. This fungus may be considered as an agent of onychomycosis, even in immunocompetent individuals, by identifying criteria that separate situations of clinical significance from those of simple contamination.

Onychomycosis: a 3-year clinicomycologic hospital-based study

BACKGROUND

Despite onychomycosis being an established entity, only a few studies are available from the Indian subcontinent. The authors investigated the comprehensive pattern of the condition.

AIM

To investigate the epidemiologic, clinical, and mycologic factors associated with onychomycosis in 50 patients using a prospective study design.

METHODS

Fifty patients with potassium hydroxide-positive tests were evaluated according to a predetermined protocal recording details of epidemiologic, clinical, and mycologic characteristics. The collected data were analyzed to determine the correlation of various parameters.

RESULTS

Distal and lateral subungual onychomycosis, total dystrophic onychomycosis, and superficial white onychomycosis variants of onychomycosis were identified, mostly in men 21-30 years of age (mean age, 34.5 years). Epidemiologic characteristics were instrumental to either initiate, perpetuate, or disseminate the disease process. Trichophyton rubrum and Trichophyton mentagrophytes were the main causative dermatophytes; yeasts and molds were less common.

CONCLUSIONS

Recognition of onychomycosis is less difficult providing the clinician is aware of the entity. Should the etiologic diagnosis be made, its eradication is desirable to surmount its implication in the society at large.

Unequivocal morphological diagnosis of fungi in morphologically abnormal nails

AIMS

To analyse the prevalence of fungi in abnormal nails by morphological diagnosis. Prevalence studies of onychomycoses in temperate climate zones have yielded widely varying rates, possibly reflecting the confounding effects of referral bias, sampling specificity and intrinsic sensitivity of the diagnostic techniques employed.

METHODS AND RESULTS

The method employed to identify fungi in nails entailed primary fixation using a non-formaldehyde-based coagulative fixative (BoonFix; Finetec, Japan) and microwave-enhanced processing to histology, followed by staining the paraffin sections with periodic acid-Schiff, using haematoxylin as a routine counterstain. The results of 990 nail samples were tabled for statistical analysis related to gender, patient age and diabetes mellitus status. In four of the 990 (< 1%) analysed cases the diagnosis was found to be equivocal using the method employed. These cases were jointly reviewed for definitive diagnosis. The overall prevalence of invasive hyphal structures was found to be 606/990 (approximately 61%). The relative risk for fungal infection in morphologically abnormal nails was found to be higher for persons < 20 years old or diabetic patients aged > or = 71 years.

CONCLUSIONS

The 61% positivity rate for fungi found justifies systematic direct submission of samples from abnormal nails for histological confirmation in order to avoid unwarranted treatment.

Non-dermatophytic molds as agents of onychomycosis in Izmir, Turkey - a prospective study

The purpose of this study was to determine the prevalence of causative non-dermatophytic filamentous fungi in onychomycosis. Totally 1,222 (1,222 x 3 = 3,666) samples of nail scrapings from 1,146 patients (from 76 patients two specimens: both from finger- and toe-nails) with prediagnosis of onychomycosis sent to the Mycology Laboratory from the Clinic of Dermatology, Ege University Hospital, Izmir, Turkey, July 2001-December 2003, were prospectively studied with conventional mycological procedures. The set criteria for the diagnosis of onychomycosis due to non-dermatophytic molds were: (1) Observation of fungal elements in 15% KOH-preparations made from nail scrapings, (2) growth of the same mold in all three consecutive cultures of the specimens taken three times from the same patient with one-week intervals, (3) no growth of a dermatophyte or yeast in three consecutive cultures. As agents of onychomycosis molds were detected in 33 (9%), dermatophytes in 175 (48%), yeasts in 150 (41%), and mixed (two different fungi) in 8 (2%) patients. In cases of mold onychomycosis, 11 (33%) had finger-nail and 22 (67%) toe-nail infection; 25 (76%) were female and 8 (24%) male; and 27 (82%) were above 40 years of age. The agents of mold onychomycosis, in order of frequency, were Aspergillus niger (7), Acremonium spp. (6), Fusarium spp. (6), Ulocladium spp. (4), sterile mycelia (2), Alternaria sp. (1), Aspergillus flavus (1), Aspergillus fumigatus (1), Aspergillus terreus (1), Cladosporium sp. (1), Paecilomyces spp. (1), Scopulariopsis sp. (1) and Trichoderma sp. (1). In conclusion, this study showed that non-dermatophytic molds were responsible for nearly 10% of onychomycoses cases attending the dermatology outpatient clinic of a university hospital in Izmir, Turkey. Since molds are common contaminants in the laboratory, cultures from consecutively taken nail scrapings should be made and carefully evaluated in order to diagnose a "mold onychomycosis".

Onychomycosis in Ceará (Northeast Brazil): epidemiological and laboratory aspects

Knowledge of epidemiological and mycological characteristics of onychomycosis has been noted by many authors as being an important tool for control of these fungal infections. This study seeks to improve knowledge of onychomycosis epidemiology and mycological features. Samples were taken from infected fingernails and toenails of 976 patients undergoing treatment at a respected Dermatology Center in Ceará, Fortaleza, CE, Brazil. Specimens from 512 patients (52%) were positive for onychomycosis. From the culture-positive samples, yeasts of the genus Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis) were dominant. The dermatophytes isolated (Trichophyton rubrum, T. tonsurans, T. mentagrophytes var. mentagrophytes) were dominant in 46 patients (12.99%). The mould Fusarium spp. was isolated from 29 patients (8.19%). Yeast of the genus Candida is the main causal factor in onychomycosis in our region. Also, the study showed the importance of performing direct examination and culture in diagnosis of onychomycosis.

Onychomycosis caused by Fusarium solani and Fusarium oxysporum in São Paulo, Brazil

Fusarium species are common soil saprophytes and plant pathogens that have been frequently reported as etiologic agents of opportunistic infections in humans. We report eight cases of onychomycosis caused by Fusarium solani (4) and Fusarium oxysporum (4) in São Paulo, Brazil. These species were isolated from toenails in all cases. The infections were initially considered to be caused by dermatophytes. The clinical appearance of the affected toenails was leukonychia or distal subungual hyperkeratosis with yellowish brown coloration. The eight cases reported here suggest that Fusarium spp. should be taken into consideration in the differential diagnosis of tinea unguium.

Use of terbinafine for tinea in Australian Aboriginal communities in the Top End

Tinea of the skin and nails is a common problem in remote Aboriginal communities of the Top End of Australia. A retrospective study was performed on data collected from 104 patients from several indigenous communities. Worksheets were filled in by district medical officers and rural general practitioners, detailing the extent of the tinea. Patients were prescribed between 4 and 12 weeks of 250 mg daily oral terbinafine. Fifty-two patients were followed up, with 45 having a good response to treatment (87%) and with 22 of these patients having full clearance of tinea (42%). A prospective study with 44 subjects was performed. The extent of the tinea was documented and fungal scrapings/clippings were taken. Forty subjects were recruited and given oral terbinafine (2-12 weeks depending on skin/nail involvement) or topical terbinafine if oral treatment was contraindicated. Twenty-five of the 40 (63%) subjects were reviewed. Twenty-three (92%) subjects that were followed up improved clinically, with 8/25 (32%) clearing completely. Twenty (80%) of followed-up patients complied fully with treatment. Terbinafine was found to be a well-tolerated and effective treatment of tinea of the skin and nails.

Characteristics of superficial mycoses in Malta

BACKGROUND

A study was conducted to determine the chief agents of superficial mycoses in Malta. Data were collected over a 5-year period from mycologic investigations carried out on all dermatologic specimens sent to the Mycology Laboratory at St. Luke's Hospital in Malta.

METHODS

In the period between January 1995 and December 1999, a total of 1271 specimens from skin, nails, or hair were collected from 1200 clinically suspected cases of dermatomycoses.

RESULTS

The fungi cultivated included dermatophytes (n = 371), yeasts (n = 33), and nondermatophyte filamentous fungi (n = 12). Trichophyton rubrum (n = 121) was the most prevalent, followed by Microsporum canis (n = 109), T. mentagrophytes (n = 80), M. gypseum (n = 27), Epidermophyton floccosum (n = 17), T. soudanense (n = 10), T. tonsurans (n = 2), T. verrucosum (n = 2), M. persicolor (n = 1), and T. violaceum (n = 1). Candida species were also cultivated, with C. parapsilosis (n = 14) being the most common, followed by C. albicans (n = 12) and C. tropicalis (n = 6). Nondermatophyte filamentous fungi were isolated from nail specimens only.

CONCLUSIONS

In this study, superficial fungal infections were reported more commonly in female (n = 207) than in male (n = 182) patients. M. canis was the chief agent of tinea capitis and tinea corporis, whilst T. rubrum was the main causative agent of tinea pedis, tinea manuum, and tinea unguium. Onychomycosis due to Candida species was more common in female than in male patients.

Yeasts of the genus Candida are the dominant cause of onychomycosis in Libyan women but not men: results of a 2-year surveillance study

BACKGROUND

The reported frequency of recovery of fungi from infected nails varies according to the geographical area.

OBJECTIVES

To establish the nature of the causal agents in a sample of the Libyan population presenting with suspected onychomycosis.

METHODS

Samples were taken from the infected fingernails of 648 patients attending the Tripoli Medical Centre.

RESULTS

Samples from 500 patients proved positive for fungi following culturing, while 476 were potassium hydroxide and culture positive. Of the culture-positive samples, yeasts of the genus Candida (C. albicans, C. parapsilosis, C. glabrata, C. guillermondii and C. tropicalis) were the dominant cause of this condition in women (417 of 434, 96%) but were responsible for only a minority of cases in men (three of 66, 5%). In contrast, dermatophytes (Trichophyton violaceum, T. rubrum, T. mentagrophytes and Microsporum canis) were responsible for this condition in the majority of cases in men (53 of 66, 80%) but only 3% (15 of 434) of cases in women. The mould Aspergillus nidulans was isolated from the nails of 10 (15%) men and two (0.5%) women.

CONCLUSIONS

The data obtained in this study reveal an almost total separation of the aetiological agents responsible for onychomycosis based on gender.

Utility of inoculum counting (Walshe and English criteria) in clinical diagnosis of onychomycosis caused by nondermatophytic filamentous fungi

Opportunistic onychomycosis caused by nondermatophytic molds may differ in treatment from tinea unguium. Confirmed diagnosis of opportunistic onychomycosis classically requires more than one laboratory analysis to show consistency of fungal outgrowth. Walshe and English in 1966 proposed to extract sufficient diagnostic information from a single patient consultation by counting the number of nail fragments positive for inoculum of the suspected fungus. Twenty fragments were plated per patient, and each case in which five or more fragments grew the same mold was considered an infection by that mold, provided that compatible filaments were also seen invading the nail tissue by direct microscopy. This widely used and often recommended method has never been validated. Therefore, the validity of substituting any technique based on inoculum counting for conventional follow-up study in the diagnosis of opportunistic onychomycosis was investigated. Sampling of 473 patients was performed repeatedly. Nail specimens were examined by direct microscopy, and 15 pieces were plated on standard growth media. After 3 weeks, outgrowing dermatophytes were recorded, and pieces growing any nondermatophyte mold were counted. Patients returned on two to eight additional occasions over a 1- to 3-year period for similar examinations. Onychomycosis was etiologically classified based on long-term study. Opportunistic onychomycosis was definitively established for 86 patients. Counts of nondermatophyte molds in initial examinations were analyzed to determine if they successfully predicted both true cases of opportunistic onychomycosis and cases of insignificant mold contamination. There was a strong positive statistical association between mold colony counts and true opportunistic onychomycosis. Logistic regression analysis, however, determined that even the highest counts predicted true cases of opportunistic onychomycosis only 89.7% of the time. The counting criterion suggested by Walshe and English was correct only 23.2% of the time. Acremonium infections were especially likely to be correctly predicted by inoculum counting. Inoculum counting could be used to indicate a need for repeat studies in cases of false-negative results from laboratory direct microscopy. Inoculum counting cannot serve as a valid substitute for follow-up study in the diagnosis of opportunistic onychomycosis. It may, nonetheless, provide useful information both to the physician and to the laboratory, and it may be especially valuable when the patient does not present for follow-up sampling.

Tinea unguium in Lahore, Pakistan

During a period of 1 year, out of 202 clinically suspected cases of tinea unguium, 53 (26%) were confirmed by mycological cultures for dermatophytes. Trichophyton rubrum was the most common fungus isolated in 46 (87%) patients, followed by T. violaceum in four (7%), T. interdigitale in two (4%) and Epidermophyton floccosum in one (2%). The disease was more common in adult males and fingernails were found to be affected more often than toenails. The distal and lateral variety was seen in 41 (77%) patients, total secondary dystrophic type in 11 (21%) and proximal subungual type in one (2%). Clinical diagnosis alone is not reliable and mycological confirmation is mandatory for this potentially curable disease.

Onychomycosis in Malaysia

The common etiological agents of onychomycosis are dermatophytes, molds and yeasts. A mycological nail investigation of onychomycosis using direct microscopy and culture was conducted by the Mycology Unit, Department of Medical Microbiology, University of Malaya from March 1996 to November 1998. The study involved 878 nail clippings or subungal scrapings from subjects with onychomycosis. On direct microscopy examination, 50% of the specimens were negative for fungal elements. On culture, 373 specimens had no growth; bacteria were isolated from 15 nail specimens. Among the 490 specimens with positive fungal cultures, 177 (36.1%) were dermatophytes, 173 (35.5%) were molds and 130 (26.5%) were Candida. There were 2% (10/490) mixed infections of molds, yeasts and dermatophytes. Trichophyton rubrum (115/177) and Trichophyton mentagrophytes (59/177) were the main dermatophytes isolated. The molds isolated were predominantly Aspergillus niger (61/173), Aspergillus nidulans (30/173), Hendersonula toruloidea (26/173) and Fusarium species (16/173). 96.9% of the Candida species identified were Candida albicans.

A review of the epidemiology of tinea unguium in the community

Tinea unguium is a common, chronic fungal infection of the nails. Many epidemiological studies have looked at the frequency with which this condition is seen in hospital outpatients clinics or mycological laboratories along with other dermatomycoses. Only recently have studies begun to emerge looking at the prevalence of this condition in populations. Hospital and mycological laboratory-based studies give valuable information about tinea unguium prevalence in a particular clinic, but cannot be compared with other studies due to confounding factors inherent in the different people attending individual clinics. From population-based studies the prevalence of tinea unguium lies between 2 and 8%. Tinea unguium increases steadily with age. It is infrequent but definitely found in children. With the increasing life expectancy in the Western world the prevalence of tinea unguium is likely to increase further without adequate prevention and treatment.

Onychomycosis in children: prevalence and treatment strategies

BACKGROUND

Onychomycosis is observed less frequently in children than adults. Until recently management of onychomycosis in children included topical formulations, oral griseofulvin, and in some cases deferral of treatment.

OBJECTIVE

We attempted to determine the prevalence of onychomycosis in North American children 18 years old or younger attending our dermatology offices (three Canadian, two U.S.) and to report the group's experience using fluconazole, itraconazole, and terbinafine for onychomycosis.

METHODS

We undertook a prospective, multicenter survey in which all children, regardless of presenting complaint, were examined for onychomycosis by a dermatologist. In instances of clinical suspicion appropriate nail samples were obtained for light microscopy and culture.

RESULTS

A total of 2500 children under age 18 were examined in the five-center survey (1117 males and 1383 females, mean +/- S.E. age: 11.2 +/- 0.1 years). There was one child with fingernail and ten with mycologically confirmed toenail dermatophyte onychomycosis. The overall prevalence of onychomycosis was 0.44%. Considering those children whose primary or referring diagnosis was not onychomycosis or tinea pedis, the prevalence of onychomycosis was 0.16%. Outside the survey we have seen six other children with dermatophyte onychomycosis; these 17 cases form the basis for the remainder of the report. Of the 17 children, eight (47%) had concomitant tinea pedis infection, and in 11 (65%) a sibling, parent, or grandparent had onychomycosis or tinea pedis. Management included topical terbinafine (two patients: one cured, one failed therapy), topical ketoconazole (one patient: clinical improvement), oral fluconazole (two patients: one cured, one had Down's syndrome and was noncompliant), oral itraconazole (four patients: three cured with subsequent recurrence at follow-up in one patient, one lost to follow-up), oral terbinafine (five patients: four cured with subsequent recurrence at follow-up in one patient, one failed therapy). One child received no therapy following discussion with the parents, one was lost to follow-up and one was found to have asymptomatic hepatic dysfunction with hepatitis C at pretherapy bloodwork.

CONCLUSION

The prevalence of onychomycosis in our sample of North American children 18 years old or younger was 0.44% (n = 2500). In the subset of children whose primary or referring diagnosis was not onychomycosis, the prevalence of onychomycosis was 0.16%. Children with onychomycosis should be carefully examined for concomitant tinea pedis, and their parents and siblings checked for onychomycosis and tinea pedis. The newer oral antifungal agents fluconazole, itraconazole, and terbinafine may be effective and well-tolerated in the treatment of onychomycosis in this age group. These drugs should be carefully evaluated in a larger cohort of children with onychomycosis.

Itraconazole therapy is effective for pedal onychomycosis caused by some nondermatophyte molds and in mixed infection with dermatophytes and molds: a multicenter study with 36 patients

BACKGROUND

Onychomycosis of the toenail caused by nondermatophyte molds alone or in combination with dermatophytes is difficult to eradicate with standard antifungal therapy.

OBJECTIVE

Our purpose was to determine the effectiveness of itraconazole in the treatment of toenail onychomycosis caused by molds alone or in combination with dermatophytes.

METHODS

We treated 36 patients with this drug given as continuous dosing (100 or 200 mg/ day) for 6 to 20 weeks or as a 1-week pulse dosing (200 mg twice daily for 1 week per month) for two to four pulses.

RESULTS

Patients with toenail onychomycosis with the following organisms were treated: Aspergillus spp. (eight patients), Fusarium spp. (four patients), Scopulariopsis brevicaulis (23 patients), and Alternaria spp. (one patient). Nineteen patients had onychomycosis with a mixed origin. At follow-up, 12 months after therapy was initiated, clinical and mycologic cure was achieved in 15 of 17 patients (88%) with onychomycosis caused by a single mold. In patients with mixed infection, a clinical cure was obtained in 16 of 19 patients (84%) and a mycologic cure in 13 of 19 patients (68%).

CONCLUSION

Itraconazole appears to be effective and safe for the treatment of toenail onychomycosis caused by some nondermatophyte molds alone or in combination with dermatophytes.

Onychomycosis in Rome, Italy

This report presents the results of a study conducted between 1985 and 1994 on onychomycosis observed in the city of Rome. Six thousand six hundred and eighty eight patients were examined during this period. Among them 1,762 (26.3%) were affected by fungal nail infections. Because the etiologic agents could not be isolated in 105 cases (6%), the results refer to 1,657 subjects (24.8% of the total), presenting with positive microscopic and cultural examinations. Thirty eight patients (2.3%) had onychomycosis of both their hands and feet. From an etiological point of view, 59.1% of the nail infections were caused by yeasts, 23.2% were infected with dermatophytes and 17.6% by non-dermatophytic fungi. The etiology of onychomycosis of the hands differed from that of the feet. Yeasts were primarily responsible for onychomycosis of the hands (86.2%), while dermatophytes caused tinea unguium peduum (48%). Fungal fingernail infections by Candida spp. were the most common (50.3%), followed by those of the feet by dermatophytes (20%). Candida albicans was responsible for 70.6% of the hand infections but for only 15.9% of those of the feet. Trichophyton rubrum and T mentagrophytes were the most common dermatophytes, mainly causing toenail infections (23.4% and 21%, respectively), while Aspergillus spp., Scopulariopsis brevicaulis, Acremonium spp. and Aspergillus niger were the most common non-dermatophytes observed. With regard to sex, the fungal nail infections were more widespread in women (72.1%) and in subjects of both sexes over the age of 50.

In vitro evaluation of griseofulvin, ketoconazole, and itraconazole against various dermatophytes in Singapore

BACKGROUND

Superficial cutaneous fungal infection, principally dermatophytosis, is an extremely common skin disease. Various in vitro test systems have been developed in recent years to determine the antifungal activity of various drugs. The minimum inhibitory concentration (MIC) obtained may give an indication of the in vivo potency of the drugs.

METHODS

One hundred patients (69 men and 31 women) with a clinical diagnosis of dermatophytosis were entered into the study. Direct microscopy and culture were done on all patients. The MICS were determined using the broth dilution method.

RESULTS

The age range was 1-76 years. The most common diagnosis was tinea corporis (36%), followed by tinea cruris (22%), and tinea pedis (19%). The most common fungus isolated was T. rubrum (58%), followed by E. floccosum (14%), and T. mentagrophytes (10%). The majority of the isolates was sensitive to the three drugs tested (griseofulvin, ketoconazole, and itraconazole). Of the isolates, 82% were sensitive to griseofulvin, 78% to ketoconazole, and 81% to itraconazole, all at a concentration of < 0.25 micrograms/mL. For T. rubrum, there were four isolates that had an MIC of > or = 64 micrograms/mL to griseofulvin, seven isolates and nine isolates with an MIC > or = 64 micrograms/mL to ketoconazole and itraconazole, respectively. T. interdigitale was relatively resistant to the three drugs in vitro with four of seven isolates having an MIC > or = 4 micrograms/mL with griseofulvin, one of seven isolate with an MIC > or = 64 micrograms/mL with ketoconazole, and three of seven isolates with an MIC > or = 32 micrograms/mL with itraconazole.

CONCLUSIONS

The in vitro antifungal activity of griseofulvin, ketoconazole, and itraconazole are similar against dermatophytes in Singapore. Griseofulvin may be given as the first-line drug for treating such infections in Singapore.