Clinical Diagnosis Of Onychomycosis Research Articles

Clinical Diagnosis and Laboratory Testing of Abnormal Appearing Toenails: A Retrospective Assessment of Confirmatory Testing for Onychomycosis in the United States, 2022-2023.

Onychomycosis is an under-recognized healthcare burden. Despite the risk of misdiagnosis, confirmatory laboratory testing is under-utilized. Histopathologic examination with polymerase chain reaction (PCR) is currently the most effective diagnostic method; it offers direct detection and identification of a fungal invasion. In this retrospective cohort study, we assessed confirmatory testing results, with matching clinical diagnoses, in 96,293 nail specimens submitted during a 9-month period from 2022 to 2023. Toenail specimens were examined using fungal culture, histopathology and/or PCR. Clinical diagnoses were identified using the International Classification of Diseases 10th Revision codes. For clinically diagnosed onychomycosis patients, the overall positivity rate was 59.4%; a similar positivity rate (59.5%) was found in patients with clinically diagnosed non-fungal nail dystrophy. Performing a histopathologic examination with PCR was more likely to provide pathogen identification results than using fungal culture. Male patients had a higher rate of onychomycosis overall; however, female patients had more non-dermatophyte mold onychomycosis caused by Aspergillus. Clinically diagnosed onychomycosis patients with a co-diagnosis of tinea pedis were more likely to test positive for onychomycosis by PCR (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 2.7-6.4), histopathology (OR: 2.5; 95% CI: 2.0-3.1) and fungal culture (OR: 3.2; 95% CI: 1.5-6.6). Our results support the use of confirmatory laboratory testing when there is a clinical diagnosis of onychomycosis.

Retrospective Analysis of Liver Enzyme Abnormalities in Patients Prescribed Terbinafine and Itraconazole for Onychomycosis.

Introduction Onychomycosis (OM) is defined as a nail fungal infection. Its prevalence increases with advancing age. Human-to-human transmission makes it a serious public health risk. Although OM is not a life-threatening disease, it has a detrimental effect on patients' quality of life. Due to the long therapy duration and potential side effects of systemic antifungal medicines, physicians may be reluctant to treat OM orally. In this study, we aimed to evaluate the effect of terbinafine and itraconazole on liver transaminases, the side effects of these treatments, and patients' adherence to systemic treatment of OM. Methods This is a retrospective study conducted in our dermatology department (Ordu University, Ordu) between June 2020 and October 2021. Hospital records were analyzed, and patients with the diagnosis of tinea unguium (ICD code B35.1) were investigated. Patients who were prescribed terbinafine or itraconazole were included in the study. Following a clinical diagnosis of OM, the researchers first tried to confirm it through direct microscopic examination with potassium hydroxide (KOH). If the direct microscopic examination was negative but the suspicion about OM continued, confirmation was done through a fungal culture. Results This study included 735 patients, of whom 409 (55.6%) were female and 326 (44.4%) were male. The research covered all of the patients who were given one of these two medications. To find patients who could apply to other hospitals, the Turkish National Healthcare System was checked in addition to hospital information. To identify patients who could apply to other healthcare institutions, all hospitals share their data with this national healthcare system. Terbinafine was used by 433 patients (76.4%), 75 patients (13.2%), and 37 patients (6.5%), respectively, for one, two, and three months. A total of 119 patients (70.8%) took itraconazole for a month, 32 patients (19%) took it for two months, and four patients (2.33%) took it for three months. At the end of the first month, the proportion of the patients with elevated aspartate transaminase (AST) levels was 5.2% for terbinafine and 0% for itraconazole. Eighteen (8.4%) patients with terbinafine had elevated alanine aminotransferase (ALT) levels, and four patients (7.5%) who were on itraconazole treatment had high ALT levels. None of the patients reported cutaneous adverse drug reactions, gastrointestinal disturbances, or headaches due to OM treatment. Also, no patients discontinued treatment because of hepatotoxicity. Conclusion In this study, none of the patients discontinued the treatment because of hepatotoxicity. According to the results of this study, oral terbinafine and itraconazole can be used with close follow-up. Baseline and regular laboratory monitoring for AST and ALT should be done to monitor liver toxicity with terbinafine and itraconazole. Besides, we did not observe other side effects like cutaneous or cardiac side effects or drug-drug interactions.

Prevalence of onychomycosis in patients with diabetes mellitus: A cross-sectional study from a tertiary care hospital in North India.

Background Though diabetes mellitus (DM) is a well-recognised risk factor for onychomycosis (OM), the epidemiology of OM in diabetic patients remains largely unexplored, especially from the Indian subcontinent. Aims and objectives To estimate the prevalence of OM in diabetic patients, to identify and analyse risk factors, and correlate the severity of nail changes with glycemic control (HBA1c). Methods This cross-sectional, analytical study involved 300 diabetic patients. Patients with the clinical diagnosis of OM, supplanted by at least two of the four tests (KOH, culture, onychoscopy and nail histopathology) were considered cases of OM. Demographic and haematological profile was analysed using chi-square test/ Fischer's exact test. Logistic regression was applied to assess the independent risk factors. Results The prevalence of OM in DM patients was 34% (102/300) and significant risk factors included; age >60 years, male gender, closed shoes, disease duration >5 years, high BMI (>25) and lack of awareness about nail changes. Distal and lateral subungual OM (78%) was the commonest presentation followed by proximal subungual OM, superficial OM and total dystrophic OM. Correlation between HbA1c and the number of nails involved was found to be significant. Limitation As cases were recruited from a hospital setting, there could be chances of Berksonian bias. Conclusion The prevalence of OM in diabetic patients is high and the severity of nail changes correlates with HbA1C levels. It is important to diagnose OM early in order to treat and prevent complications.

Assessment of the Clinical Diagnosis of Onychomycosis by Dermoscopy.

BackgroundAs a common clinical superficial fungal infection, the diagnosis of onychomycosis relies on clinical features, traditional KOH direct microscopy and fungal culture. In recent years, dermoscopy has been widely used in the diagnosis and treatment of infectious diseases and has provided new options for the diagnosis of onychomycosis.ObjectiveTo evaluate the value of dermoscopy in the clinical diagnosis of onychomycosis and to explore the relationship between each clinical subtype and the dermoscopic pattern.MethodsA retrospective study of 114 cases of clinically suspected onychomycosis was conducted to compare the differences between dermoscopy and fungal pathogenic examination (microscopy and culture) in the diagnostic sensitivity of onychomycosis and to analyze the relationship between nine common dermoscopic modalities and clinical subtypes of onychomycosis.ResultsAmong the 114 proposed patients, 87 nails with positive fluorescent staining microscopy and/or positive fungal cultures were diagnosed as onychomycosis. The sensitivity and specificity of dermatoscopy, using the mycological findings as a reference, were 86.21 and 33.33%, respectively. The incidence of common dermatoscopic patterns in the 87 nails with confirmed onychomycosis was as follows: white flocculation in 76 cases (87.35%), longitudinal nail pattern in 72 cases (82.76%), jagged changes in the distal nail plate in 69 cases (79.31%) and yellow staining in 46 cases (52.87%), these four patterns were more commonly seen in the distal lateral subungual onychomycosis and total dystrophic onychomycosis, but there was no statistical difference in the positive dermatoscopic pattern between these two types (P > 0.05).ConclusionDermoscopy can be an important aid in the diagnosis of onychomycosis, especially when fungal microscopy or culture is not appropriate, but this method is still not a substitute for fungal microscopy and culture.

Onychomycosis: correlation between the dermoscopic patterns and fungal culture

ObjectiveThe aim was to correlate the results of fungal investigations (Direct KOH and fungal culture) with dermoscopic findings on clinically suspected cases of onychomycosis and to evaluate dermoscope as an alternative tool in diagnosis of such cases.BackgroundOnychomycosis is a fungal infection of the nail plate or nail bed. There are four clinical types of onychomycosis: distal and lateral subungual onychomycosis (DLSOM), proximal subungual onychomycosis (PSOM), white superficial onychomycosis (WSOM), and total dystrophic onychomycosis (TDOM).Patients and methodsThis study was conducted at Menoufia University Hospital on 44 patients with a clinical diagnosis of onychomycosis. Full history taking and complete general examination were performed to detect associated systemic diseases. Dermatological examination was done to exclude any associated dermatological diseases that can affect the nails, such as psoriasis, lichen planus, alopecia areata, eczema and/or melanomas. Photography of the nail using digital camera and dermoscopic examination of the nail also were done to our patients.ResultsJagged proximal edge, longitudinal white striae and chromonychia were more frequently observed in patients with DLSOM. Straight onycholytic area was observed in 4 cases of DLSOM. Subungual hyperkeratosis was significantly associated with TDOM. Leukonychia was significantly associated with PSOM. Our results reported that, all dermoscopic patterns were significantly associated with positive fungal growth cultures.ConclusionDermoscope may be considered quick, easy, helpful, effective, and inexpensive tool for confirmation the diagnosis of clinically suspected cases of onychomycosis.

A Mycological and Molecular Epidemiologic Study on Onychomycosis and Determination In Vitro Susceptibilities of Isolated Fungal Strains to Conventional and New Antifungals.

BackgroundOnychomycosis is one of the most common and recurrent dermatological diseases worldwide. The antimycotic activity of prescribed medications varies according to the causative agents, and treatment failure rates exceeding 30%. This study aimed to assess the epidemiological profile of onychomycosis in Iran. Also, the susceptibilities to conventional and new antifungals were investigated.MethodsIn this descriptive cross-sectional study, during the period of 18 months starting from September 2019 until March 2020, 594 nail specimens were obtained from patients who presented nail changes compatible with a clinical diagnosis of onychomycosis. The patients were referred from different cities, including Tehran, Kermanshah, Arak, Kashan, Rasht, Qom, Urmia, Zahedan, Hamadan, Zanjan, Borujerd, Bushehr, and Yazd. All the samples were subjected to microscopic examination and fungal culture. Fungi identified were confirmed through the PCR-sequencing method. The susceptibility to itraconazole, fluconazole, terbinafine, griseofulvin, posaconazole, ravuconazole, efinaconazole, luliconazole, and tavaborole was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, document M38-A2 for filamentous fungi, and document M27-A3 for yeasts.Results594 patients were included. Of these, in 179 cases (30.1%) (95% CI:0.3 ± 0.037) onychomycosis was confirmed. The majority of patients were ≥ 60 years of age (n=58, 32.6%) and female (n=113, 63.1%). Saprophytic fungi accounted for the vast majority of the nail isolates (n=92, 51.4%) (95% CI:0.051 ± 0.0.073), followed by dermatophytes (n=45, 25.1%) (95% CI:0.25 ± 0.063), and yeasts (n=42, 23.5%) (95% CI:0.23 ± 0.061). Diabetes mellitus (77.3%), hypothyroidism (18.2%), and solid tumors (4.5%) were documented as the most prevalent underlying conditions. Antifungal susceptibility testing was performed against 60 fungal isolates (20 each of Candida species, saprophytic fungi, and dermatophytes). Efinaconazole, ravuconazole, and luliconazole were the most active agents against Candida species. Also, luliconazole, posaconazole, and efinaconazole were most potent against dermatophytes. Luliconazole had the greatest antifungal activity against saprophytic fungi.ConclusionsThe prevalence of onychomycosis in Iranian patients was relatively high. LUL exhibited potent antifungal activity against the three groups of fungi tested, determining its broad-spectrum antimycotic activity and its probable use as the first-line therapy for onychomycosis.

Onychomycosis in onychodystrophy: a hospital-based clinico-mycological study

<p class="abstract"><strong>Background:</strong> Onychomycosis and onychodystrophy are both characterised clinically as disruption of nail plate characterised by thickening, disfiguration and discolouration. Onychomycosis in onychodystrophy is a diagnostic challenge. Similarly, onychodystrophy could also be treated unwarrantedly for fungus. Hence this study was carried out to determine the prevalence of onychomycosis in patients with onychodystrophy and to study the risk factors associated with the same.</p><p class="abstract"><strong>Methods:</strong> This descriptive study was done in 50 patients with onychodystrophy attending DVL OPD in a tertiary care hospital. After getting informed consent the nails were cleansed with absolute alcohol and nail clipping was taken for KOH and culture. The results were entered in a master sheet and analyzed.<strong></strong></p><p class="abstract"><strong>Results:</strong> Onycholysis, onychomadesis, chromonychia, thickened nail plate and loss of cuticle were the common features observed. Culture from 13/50 (26%) patients were found to be positive for fungal growth. In 13 patients with onychomycosis, 5 patients belonged to more than 50 years, seven patients (53.8%) were housewives. Three patients with onychodystrophy had psoriasis of which 2 (15.4%) patients proved positive for onychomycosis<em>. Aspergillus niger</em> 10 (76.9%) was the most common organism followed by <em>Rhizopus</em> 2 (15.4%) patients and 1 (7.7%) patient with <em>Geotrichium candidum</em>.</p><p class="abstract"><strong>Conclusions:</strong> We concluded that prevalence of onychomycosis in patients with onychodystrophy was 26%. Male gender, age >50, household activities and wetworks were associated risk factors of onychomycosis. Since clinical diagnosis of onychomycosis in onychodystrophy is difficult, appropriate lab investigations like KOH mount and fungal culture should be made mandatory to enable better patient care and clinical outcome.</p>

Onychomycosis in patients with multiple sclerosis: prevalence, clinical description, mycological, and dermoscopic study in a Mexican population.

Multiple sclerosis (MS) is a chronic demyelinating disease related to HLA-DR8. Susceptibility to onychomycosis has been found in Mexican mestizos with HLA-DR8. The frequency of onychomycosis in this neurological disease is unknown. To determine the frequency of onychomycosis and its clinical, mycological, and dermoscopic characteristics in patients with MS in comparison with the general population. Observational, cross-sectional, case-control study in patients with MS from October 2017 to February 2018. Age, gender, MS type, and time of progression from diagnosis to date and baseline treatment were collected after signed informed consent. A neurological exploration and clinical examination of fingernails and toenails for onychomycosis was conducted. Mycological and dermoscopic studies of the infected nails were performed on patients with clinical diagnosis of onychomycosis. A healthy control group was taken for each case (1:1), paired by age and gender. The frequency of onychomycosis in patients with MS was higher than the healthy population (32% vs. 26%, P=0.509). A higher frequency of non-dermatophyte fungi was found, although it was not statistically significant. The clinical manifestations and dermoscopic findings in patients with MS and onychomycosis were similar to those of the general population. The frequency of onychomycosis in patients with MS is slightly higher than that of the general population. A possible association of HLA-DR8 as a susceptibility factor for onychomycosis is proposed. The etiology of opportunistic fungi in MS patients with onychomycosis may be related to immunosuppressive treatment.

Clinico-mycological study of onychomycosis in a tertiary care hospital-A cross-sectional study.

Onychomycosis (OM), has a worldwide prevalence of 5% and 0.5%-5% in India. Trichophyton. rubrum (T rubrum) and T mentagrophytes are the most commonly isolated fungi. As the clinical and mycological characteristics change with time and geographical region; it is important to study the temporal and topographic patterns periodically. The study was conducted to identify the epidemiological and clinico-mycological characteristics of patients with OM attending a tertiary care hospital in Delhi. Hundred patients with clinical diagnosis of OM were recruited. Among these, 88 patients who tested positive for OM on direct microscopy with KOH, culture and/or histopathology with periodic acid-Schiff were included in the study. The clinico-mycological characteristics and risk factors associated with OM were evaluated. OM was more common in males (M:F=2.5:1). The mean age of patients with OM was 39±15.3years (SE 1.52) with mean disease duration of 27.6±46.1months (SE 4.9). Seventeen (19.3%) patients had concomitant diabetes mellitus. The patients displayed mean body mass index (BMI) of 25.67±1.35kg/sq m. Concurrent dermatophytosis of skin was present in 35 (39.77%) patients. Two feet-one hand syndrome was present in 5 patients. Fingernail involvement without toenail involvement was more common than toenail involvement alone. (43.18% vs 38.63%). Distal and lateral subungual OM (DLSO) was the commonest clinical variant (81.8%). Mycological culture showed growth in 47 (53.40%) patients. Dermatophytes were isolated in majority, that is in 30 (63.82%) patients followed by non-dermatophytic moulds (NDM) in 7 (14.8%) and Candida spp. in the remaining 10 (21.27%) patients.

“Clinico- Mycological Profile of Onychomycosis –A Study in A Tertiary Care Hospital in Kolkata”

Clinical and mycological features of onychomycosis show variation with time and place. Onychomycosis is a major public health problem with high incidence, associated morbidity and long lasting treatment with anti-fungal agents. A study was carried out on 118 patients having clinical diagnosis of onychomycosis, attending the dermatology out-patient department of R. G. Kar Medical College, Kolkata. Nail clippings were subjected to direct microscopy and cultured on Sabouraud's Dextrose Agar with antibiotics. The commonest age group affected was 21-40 years with a female preponderance and housewives were most commonly affected group. Finger nail involvement were more frequent and distolateral subungal onychomycosis (DLSO) was the most common clinical type observed . Out of 118 cases total KOH positivity was in 72 (61.01%) and culture positivity was in 62 (52.54%). Total culture positive cases were 62 and total number of fungi identified were 66 as dual pathogen had been identified in four cases . Among 66 culture positive isolates dermatophytes were 30 ( 45.55%), candida 21(31.82%) and non-dermatophyte moulds (NDM) 15 ( 22.73%) . T. rubrum was the commonest etiological agent. Among dermatophytes, Trichophyton rubrum, and among NDM, Fusarium moniliforme, were the most common isolates identified in our study.

A Retrospective Study of Onychomycosis, Clinical Diagnosis Versus Laboratory Diagnosis

INTRODUCTION AND OBJECTIVES: Onychomycosis is defined as a fungal infection of the nail usually caused by a dermatophyte. This retrospective study will compare the diagnosis of onychomycosis based on clinical exam findings in comparison to laboratory results. METHODS: Clinical diagnosis of onychomycosis of the nail is made through visual inspection of the nail. The characteristics that define a clinical diagnosis of onychomycosis include but is not limited to: thickness of nail, discoloration (yellow, black, and/or brown), crumbly texture, subungual debris, subungual fluid, splitting of the nail, and/or nail dystrophy. Patients were treated with either a topical or oral drug and this was based solely on the clinical characteristics of the nail with no further lab testing. The most recent 50 charts from the past three years (1/1/2013 to 1/31/2016) were utilized to conduct this retrospective study. The charts were analyzed based on the following criteria: patients that were clinically diagnosed with onychomycosis and also had a positive laboratory results that included a PAS, PCR, or KOH staining. RESULTS: We found that there was a higher incidence of clinically positive diagnosis vs. laboratory culture positive results. CONCLUSIONS: As expected fungal nail cultures are sometimes less sensitive than our clinical evaluation. This may be due to false negatives or failure to obtain an adequate sample for culture analysis. This may effect treatment standard of care and accuracy of treatment.

The clinical diagnosis of onychomycosis by physicians: Is a confirmatory test necessary?

The clinical diagnosis of onychomycosis by physicians: Is a confirmatory test necessary?

The diagnostic value of fungal fluorescence in onychomycosis

Fluorescence of pathogenic fungi has been previously shown when hematoxylin and eosin-stained sections are examined under a fluorescent microscope. We hypothesize that this phenomenon could aid in the evaluation of nail specimens for onychomycosis. Forty-eight routinely stained nail sections of periodic acid-Schiff (PAS)-positive onychomycosis, along with 23 PAS-negative control specimens with a clinical diagnosis of onychomycosis, were studied under a fluorescent microscope to determine the clinical usefulness of this technique. In most cases, fluorescence of fungal organisms was noted. Fungi were identified by their tubular or annular shapes with fluorescence surrounding them. The sensitivity and specificity of the method were 96 and 90%, respectively. In some cases, it was difficult to identify the fungi because of the relative paucity of organisms, weak fluorescence and high background fluorescence of eosinophilic nail keratin. We conclude that fluorescence microscopy can be used as a rapid screening tool for identification of fungi in nail specimens.

Natural coniferous resin lacquer in treatment of toenail onychomycosis: an observational study

In in vitro tests, natural coniferous resin from the Norway spruce (Picea abies) is strongly antifungal. In this observational study, we tested the clinical effectiveness of a lacquer composed of spruce resin for topical treatment of onychomycosis. Thirty-seven patients with clinical diagnosis of onychomycosis were enrolled into the study. All patients used topical resin lacquer treatment daily for 9 months. A mycological culture and potassium hydroxide (KOH) stain were done from nail samples in the beginning and in the end of the study. Treatment was considered effective, if a mycological culture was negative and there was an apparent clinical cure. At study entry, 20 patients (20/37; 54%; 95% CI: 38–70) had a positive mycological culture and/or positive KOH stain for dermatophytes. At study end, the result of 13 patients was negative (13/19; 68%; 95% CI: 48–89). In one case (1/14; 7%; 95% CI: 0–21) the mycological culture was initially negative, but it turned positive during the study period. By 14 compliant patients (14/32; 44%; 95% CI: 27–61), resin lacquer treatment was considered clinically effective: complete healing took place in three cases (9%) and partial healing in 11 cases (85%). The results indicate some evidence of clinical efficacy of the natural coniferous resin used for topical treatment of onychomycosis.

Características clínicas, epidemiológicas y microbiológicas de la onicomicosis en un laboratorio de referencia, Manizales (Caldas), 2009

IntroductionOnychomycosis is the leading cause of nail disease and represents 30% of superficial fungal infections. The fungi that cause the condition vary according to geographic location and individual risk factors. Even with the identification of the causative agent, the treatment failure rate is high. ObjectiveTo establish the clinical, epidemiological and microbiological causes of onychomycosis in patients over 16 years old in the city of Manizales. Materials and methodsA prospective descriptive study in 232 patients with clinical diagnosis of onychomycosis sent from different medical centers of Manizales in 2009. A sample collection, direct examination with KOH 20% and dimethyl sulfoxide 36%, culture in Saboreaud agar with antibiotics in all cases were performed. Identification was done for the 146 obtained isolates with specific methods for dermatophytes, yeasts and molds. ResultsThe most common presentation of the disease was the distal; the disease is more commonly associated with occlusive footwear, for females. The clinical manifestations was the type subungual distal in patients over 70 years old; the most frequently isolated agents were Trichophyton rubrum (26.7%), Fusarium spp (14.4%), T. mentagrophytes (11%), Candida tropicalis (11%), Candida krusei (6%) and Geotrichum candidum (6%). ConclusionsThere was a female predominance of onychomycosis in Manizales and a the high frequency of non-dermatophyte fungi; T. rubrum was the most frequently isolated dermatophyte; the frequency of patients with KOH or positive culture is higher than 70% in all age groups. It was found that age is not a risk factor for the disease.

HLA‐DR6 association confers increased resistance to T. rubrum onychomycosis in Mexican Mestizos

Onychomycosis is multifactorial in origin. Studies have suggested an autosomal dominant pattern of inheritance and human leukocyte antigen DR4 (HLA-DR4) has been shown to protect against onychomycosis in an Ashkenazi Jewish population. This study investigates HLA class II association in a Mexican Mestizo population with Trichophyton rubrum onychomycosis. This was a prospective case-control study. Mexican Mestizos with a clinical diagnosis of onychomycosis and culture positive for T. rubrum were recruited, together with age- and sex-matched controls. First-degree relatives were also investigated for onychomycosis. Case-control samples were HLA typed by polymerase chain reaction sequence-specific primer based analysis. Twenty-one cases and 42 controls were recruited with a mean age of 40 years (range: 18-58 years). HLA-DR6 was found in seven (33%) cases and 19 (45%) controls [P < 0.023, odds ratio (OR) = 0.088, 95% confidence interval (CI): 0.01-0.71]. Six (29%) cases and three (7%) controls had an affected child (P < 0.043, OR = 9.15, 95% CI: 1.07-78.31), and 13 (62%) cases and 12 (29%) controls had an affected first-degree relative (P < 0.02, OR = 4.0, 95% CI: 1.1-14.3). These results suggest that HLA-DR6 confers protection against the development of onychomycosis in a Mexican Mestizo population. Having an affected first-degree relative significantly increases the risk of onychomycosis, suggesting genetic susceptibility.

Successive mycological nail tests for onychomycosis: a strategy to improve diagnosis efficiency

Onychomycosis is a fungal infection of nails caused by dermatophytes, yeasts and moulds, accounting for about 50% of onychopathies. A high frequency of onychomycosis caused by Candida species has been reported during the last few years in northeast Brazil, as well as in other regions of the world. A clinical diagnosis of onychomycosis needs to be confirmed through laboratory exams. We evaluated the importance of serial repetition of direct microscopic exams and fungal culture for the diagnosis of onychomycosis in the city of Fortaleza, Ceará, in northeast Brazil. We first made a retrospective study of 127 patients with onychomycosis, identifying the fungi that had been isolated from fingernails and toenails. We then made a prospective study of 120 patients, who were submitted to three successive mycological examinations. Ungual residues were scraped off and directly examined with a microscope and fungal cultures were made. In the retrospective study, in which only one sample was analyzed, the incidence of onychomycosis was 25.0%. In our prospective study, in which we had data from successive mycological examinations, 37.8% had onychomycosis. The most commonly isolated fungi in both studies were yeasts from the genera Candida, especially C albicans, C. parapsilosis and C. tropicalis. We found a high proportion of onychomycosis caused by Candida species. We also concluded that serial repetition of direct microscopic examination and fungal culture, with intervals of 2-5 days improved the diagnosis of onychomycosis. We suggest that this laboratorial strategy is necessary for accurate diagnosis of this type of mycosis, especially when the standard procedures fail to diagnose fungal infection, despite strong clinical suspicion.

GMS is superior to PAS for diagnosis of onychomycosis

Onychomycosis is a common cause of deformed nails. Periodic acid-Schiff (PAS) stains are more sensitive than fungal cultures for diagnosing onychomycosis. We performed a retrospective study comparing the use of PAS and Gomori methenamine silver (GMS) stains for histopathologic diagnosis of onychomycosis. GMS stains were performed on 20 PAS-positive and 51 PAS-negative cases from nail biopsies with a clinical diagnosis of onychomycosis. The PAS stained slides and GMS stained slides were evaluated for the presence of fungal hyphae. The results were analyzed with McNemar's test. All 20 PAS-positive cases were also positive with GMS stains. Of the 51 PAS-negative cases, GMS stains detected an additional five cases with fungal hyphae. GMS stains were quantitatively superior (p < 0.0253). GMS stains were also qualitatively superior. More fungal hyphae were highlighted and fungal hyphae were more easily recognized on low or medium power magnification. GMS stains are superior to PAS stains for the routine diagnosis of onychomycosis.

Onychomycosis - epidemiology, diagnosis and management

Onychomycosis is a fungal infection of nails caused by dermatophytes, yeasts or nondermatophyte molds and represents about 30% of mycotic cutaneous infections. Increasingly onychomycosis is being viewed as more than a mere cosmetic problem. In spite of improved personal hygiene and living environment, onychomycosis continues to spread and persist. The prevalence rate of onychomycosis is determined by age, predisposing factor, social class, occupation, climate, living environment and frequency of travel. Onychomycosis in immunocompromised patients can pose a more serious health problem. Dermatophytes are the most frequently implicated causative agents in onychomycosis. Previously regarded as contaminants, yeasts are now increasingly recognised as pathogens in fingernail infections, as are some moulds. Clinical diagnosis of onychomycosis is based on the patients' history; a physical examination, microscopy and culture of nail specimens. The treatment of onychomycosis has been attempted throughout the ages, but only in the last two decades have safe, effective systemic treatments been available for this chronic superficial fungal disease. Oral Griseofulvin and Ketoconazole; once the agents of choice for the treatment of onychomycosis, have been superseded by newer systemic compounds that have a higher cure and lower relapse rates, cause fewer side effects and are suitable for short-term dosing.

The incremental diagnostic yield of successive re-cultures in patients with a clinical diagnosis of onychomycosis

The incremental diagnostic yield of successive re-cultures in patients with a clinical diagnosis of onychomycosis