Diseases mimicking onychomycosis

Diagnosis of Onychomycosis: Utility of an Immunochromatography Strip Test Compared with Conventional Culture

BACKGROUND

Ringworm is highly prevalent in our setting and is frequently observed in our routine clinical practice. Diagnostic confirmation depends on techniques that are not always accessible (PCR), with highly variable sensitivity depending on the observer (direct microscopy) or delayed results (culture, histopathology). Recently, an immunochromatography-based rapid test (Diafactory®) for the antigenic detection of dermatophytes has been developed. This diagnostic tool can help diagnose ringworm, allowing early initiation of treatment and fewer consultation visits.

OBJECTIVE

To determine the sensitivity and specificity of the rapid antigen detection test compared to conventional culture.

MATERIAL AND METHODS

For a full year, 333 nail samples were collected from patients with suspected onychomycosis. The rapid test and the conventional culture were simultaneously performed on each sample. Those with a positive antigenic test result began treatment early. The remaining patients had appointments for serial cultures and subsequent medical consultation to evaluate the results.

RESULTS

Compared to conventional culture, the sensitivity and specificity rates of the rapid antigen detection test are 97.2% and 80.7%, respectively.

CONCLUSION

The effectiveness of the rapid antigen detection test is similar to that of conventional culture for the detection of dermatophytes in nail samples. It is a quick and simple diagnostic technique that reduces the number of patient visits to the hospital, and allows early treatment start.

Line-field confocal optical coherence tomography, a novel non-invasive tool for the diagnosis of onychomycosis

BACKGROUND AND OBJECTIVES

Onychomycosis is common and important to distinguish from other nail diseases. Rapid and accurate diagnosis is necessary for optimal patient treatment and outcome. Non-invasive diagnostic tools have increasing potential for nail diseases including onychomycosis. This study evaluated line-field confocal optical coherence tomography (LC-OCT) as a rapid non-invasive tool for diagnosing onychomycosis as compared to confocal laser scanning microscopy (CLSM), optical coherence tomography (OCT), and conventional methods.

PATIENTS AND METHODS

In this prospective study 86 patients with clinically suspected onychomycosis and 14 controls were examined using LC-OCT, OCT, and CLSM. KOH-preparation, fungal culture, PCR, and histopathology were used as comparative conventional methods.

RESULTS

LC-OCT had the highest sensitivity and negative predictive value of all methods used, closely followed by PCR and OCT. Specificity and positive predictive value of LC-OCT were as high as with CLSM, while OCT scored much lower. The gold standard technique, fungal culture, showed the lowest sensitivity and negative predictive value. Only PCR and culture allowed species differentiation.

CONCLUSIONS

LC-OCT enables quick and non-invasive detection of onychomycosis, with advantages over CLSM and OCT, and similar diagnostic accuracy to PCR but lacking species differentiation. For accurate nail examination, LC-OCT requires well-trained and experienced operators.

Konfokale Line-Field optische Kohärenztomographie, ein innovatives nichtinvasives Instrument zur Diagnose der Onychomykose: Line-field confocal optical coherence tomography, a novel non-invasive tool for the diagnosis of onychomycosis

Hintergrund und Ziele

Onychomykose ist weit verbreitet und sollte von anderen Nagelerkrankungen unterschieden werden. Eine rasche und genaue Diagnostik ist für die optimale Behandlung des Patienten und ein bestmögliches Ergebnis erforderlich. Nichtinvasive Techniken haben ein wachsendes Potenzial bei der Diagnose von Nagelerkrankungen, einschließlich Onychomykose. In dieser Studie wurde die konfokale Line‐Field optische Kohärenztomographie (LC‐OCT) als schnelle nichtinvasive Methode zur Diagnose von Onychomykose im Vergleich zur konfokalen Laserscanmikroskopie (KLM), optischen Kohärenztomographie (OCT) und konventionellen Methoden bewertet.

Patienten und Methodik

In dieser prospektiven Studie wurden 86 Patienten mit klinischem Verdacht auf Onychomykose und 14 Kontrollen mittels LC‐OCT, OCT und KLM untersucht. KOH‐Präparation, Pilzkultur, PCR und Histopathologie wurden als vergleichende konventionelle Methoden eingesetzt.

Ergebnisse

LC‐OCT hatte die höchste Sensitivität und den höchsten negativen Vorhersagewert aller verwendeten Methoden, dicht gefolgt von PCR und OCT. Die Spezifität und der positive Vorhersagewert der LC‐OCT waren genauso hoch wie bei der KLM, während OCT deutlich schlechter abschnitt. Das Goldstandardverfahren Pilzkultur zeigte die geringste Sensitivität und den niedrigsten negativen Vorhersagewert. Nur PCR und Kultur ermöglichten eine Differenzierung der Pilzspezies.

Schlussfolgerungen

LC‐OCT ermöglicht eine schnelle und nichtinvasive Diagnostik von Onychomykose, mit Vorteilen gegenüber KLM und OCT und ähnlicher diagnostischer Genauigkeit wie die PCR, aber ohne Differenzierung der Pilzarten. Für eine genaue Nageluntersuchung erfordert die LC‐OCT gut geschulte und erfahrene Anwender.

Literaturübersicht zu Veränderungen der Zehennägel bei chronischer venöser Insuffizienz

Das Patientenkollektiv einer phlebologischen Sprechstunde weist häufig pathologisch veränderte Zehennägel auf. Es stellt sich die Frage, ob ein Zusammenhang zwischen chronischer venöser Insuffizienz und einer Onychodystrophie besteht. Denkbar sind sowohl nichtmykotische Nagelwachstumsstörungen als auch eine Prädisposition für Onychomykosen durch eine Minderperfusion im Rahmen der venösen Insuffizienz. Die wenige Literatur, die es zu dieser Thematik gibt, zeigt unterschiedliche Ergebnisse, welche hier genauer erläutert werden.

Optimal diagnosis and management of common nail disorders

Nail conditions are not only aesthetic concerns, and nail changes may be a clue to an underlying systemic diseases or infection. Without timely treatment, nail diseases can continue to worsen and significantly impair performance of daily activities and reduce quality of life. Examination of the nails is essential at every medical visit, and may uncover important findings. Brittle nail syndrome, onychomycosis, paronychia, nail psoriasis, longitudinal melanonychia, Beau's lines, onychomadesis and retronychia are common nail disorders seen in clinical practice. These conditions stem from infectious, inflammatory, neoplastic and traumatic aetiologies. Though each nail condition presents with its own distinct characteristics, the clinical findings may overlap between different conditions, resulting in misdiagnosis and treatment delays. Patients can present with nail plate changes (e.g. hyperkeratosis, onycholysis, pitting), discolouration, pain and inflammation. The diagnostic work-up of nail disease should include a detailed history and clinical examination of all 20 nail units. Dermoscopy, diagnostic imaging and histopathologic and mycological analyses may be necessary for diagnosis. Nail findings concerning for malignancy should be promptly referred to a dermatologist for evaluation and biopsy. Nail disease management requires a targeted treatment approach. Treatments include topical and/or systemic medications, discontinuation of offending drugs or surgical intervention, depending on the condition. Patient education on proper nail care and techniques to minimize further damage to the affected nails is also important. This article serves to enhance familiarity of the most common nail disorders seen in clinical practice. It will highlight the key clinical manifestations, systematic approaches to diagnosis and treatment options for each nail condition to improve diagnosis and management of nail diseases, as well as patient outcomes.Key messagesNail disease is not only a cosmetic issue, as nail changes can indicate the presence of a serious underlying systemic disease, infection or malignancy.Nail pain and changes associated with NP are physically and emotionally distressing and may contribute to functional impairment and diminished quality of life.LM is a hallmark sign of subungual melanoma and this finding warrants further investigation to rule out malignancy.

Deep learning-based diagnosis models for onychomycosis in dermoscopy

BACKGROUND

Onychomycosis is a common disease. Emerging noninvasive, real-time techniques such as dermoscopy and deep convolutional neural networks have been proposed for the diagnosis of onychomycosis. However, deep learning application in dermoscopic image hasn't been reported.

OBJECTIVES

To explore the establishment of deep learning-based diagnostic models for onychomycosis in dermoscopy to improve the diagnostic efficiency and accuracy.

METHODS

We evaluated the dermoscopic patterns of onychomycosis diagnosed at Sun Yat-sen Memorial Hospital, Guangzhou, China from May 2019 to February 2021 and included nail psoriasis and traumatic onychodystrophy as control groups. Based on the dermoscopic images and the characteristic dermoscopic patterns of onychomycosis, we gain the faster region-based convolutional neural networks to distinguish between nail disorder and normal nail, onychomycosis and non-mycological nail disorder (nail psoriasis and traumatic onychodystrophy). The diagnostic performance is compared between deep learning-based diagnosis models and dermatologists.

RESULTS

All of 1155 dermoscopic images were collected, including onychomycosis (603 images), nail psoriasis (221 images), traumatic onychodystrophy (104 images) and normal cases (227 images). Statistical analyses revealed subungual keratosis, distal irregular termination, longitudinal striae, jagged edge, marble-like turbid area, and cone-shaped keratosis were of high specificity (>82%) for onychomycosis diagnosis. The deep learning-based diagnosis models (ensemble model) showed test accuracy /specificity/ sensitivity /Youden index of (95.7%/98.8%/82.1%/0.809), (87.5%/93.0%/78.5%/0.715) for nail disorder and onychomycosis. The diagnostic performance for onychomycosis using ensemble model was superior to 54 dermatologists.

CONCLUSIONS

Our study demonstrated onychomycosis had distinctive dermoscopic patterns, compared with nail psoriasis and traumatic onychodystrophy. The deep learning-based diagnosis models showed a diagnostic accuracy of onychomycosis, superior to dermatologists.

Onychomycosis: An Updated Review

Background: Onychomycosis is a common fungal infection of the nail.

Objective: The study aimed to provide an update on the evaluation, diagnosis, and treatment of onychomycosis.

Methods: A PubMed search was completed in Clinical Queries using the key term “onychomycosis”. The search was conducted in May 2019. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. The search was restricted to English literature. Patents were searched using the key term “onychomycosis” in www.freepatentsonline.com.

Results: Onychomycosis is a fungal infection of the nail unit. Approximately 90% of toenail and 75% of fingernail onychomycosis are caused by dermatophytes, notably Trichophyton mentagrophytes and Trichophyton rubrum. Clinical manifestations include discoloration of the nail, subungual hyperkeratosis, onycholysis, and onychauxis. The diagnosis can be confirmed by direct microscopic examination with a potassium hydroxide wet-mount preparation, histopathologic examination of the trimmed affected nail plate with a periodic-acid-Schiff stain, fungal culture, or polymerase chain reaction assays. Laboratory confirmation of onychomycosis before beginning a treatment regimen should be considered. Currently, oral terbinafine is the treatment of choice, followed by oral itraconazole. In general, topical monotherapy can be considered for mild to moderate onychomycosis and is a therapeutic option when oral antifungal agents are contraindicated or cannot be tolerated. Recent patents related to the management of onychomycosis are also discussed.

Conclusion: Oral antifungal therapies are effective, but significant adverse effects limit their use.Although topical antifungal therapies have minimal adverse events, they are less effective than oral antifungal therapies, due to poor nail penetration. Therefore, there is a need for exploring more effective and/or alternative treatment modalities for the treatment of onychomycosis which are safer and more effective.

Dermoscopic Features of Distal Lateral Subungual Onychomycosis

Background:

Onychomycosis is a very common disease and accounts for upto 50% of the diseases affecting the nail apparatus. Diagnosis of onychomycosis is usually confirmed with the help of a potassium hydroxide (KOH) mount and fungal culture. Onychoscopy can be a handy and additional tool for the diagnosis.

Aims and Objectives:

To determine the dermoscopic findings in distal lateral subungual onychomycosis (DLSO).

Materials and Methods:

A prospective study of 60 nails with a clinical and mycological diagnosis (KOH with Chicago sky blue positive) of DLSO. Dermoscopic examination was performed using a Heine delta 20 plus dermatoscope and the features were recorded.

Results:

Longitudinal striae and jagged proximal edges seen in all 60 (100%) patients. Intermittent spiked pattern was seen in 47 nails (78.3%). Chromonychia and distal irregular termination were noticed in 23 (38.3%) and 7 (11.7%) nails, respectively.

Conclusions:

Onychoscopy can be used as an important diagnostic tool while evaluating nail disease, especially in DLSO.

Limitations:

Small study sample and lack of comparison with other nail diseases that manifests with distal onycholysis.

Patient-reported outcomes from two randomised studies comparing once-weekly application of amorolfine 5% nail lacquer to other methods of topical treatment in distal and lateral subungual onychomycosis

Patient adherence is a key consideration in the choice of a topical regimen for the treatment of onychomycosis. The objective of this study was to investigate patient-reported outcomes (treatment utilisation, adherence and satisfaction) in onychomycosis treated with once-weekly amorolfine 5% nail lacquer versus once-daily ciclopirox 8% nail lacquer (Study A) or once-daily urea 40% ointment/bifonazole 1% cream combination regimen (Study B). Study A: Subjects received amorolfine and ciclopirox on opposite feet for 12 weeks. Study B: Subjects received amorolfine and urea/bifonazole on opposite feet for 6-7 weeks. Assessments included subject adherence as per label, treatment preference and questionnaire. Study A: More subjects adhered to amorolfine (85%) than to ciclopirox (60%) (P = .025). Overall, subjects were satisfied (95% vs 100%, respectively) and the treatments were balanced in terms of preference (50% vs 45%) at week 12. Study B: More subjects adhered to amorolfine dosage (81.8%) than to the dosage of the urea/bifonazole combination regimen (59.1%) (P = .096). At the end of study, 85.7% of subjects preferred amorolfine versus 14.3% for urea/bifonazole. Fewer subjects experienced local side effects with amorolfine (4.5%) compared to urea (27.3%) and bifonazole (15%). Amorolfine 5% nail lacquer offers a simple and convenient treatment option, which may result in improved patient adherence and consequently lead to improved efficacy and patient satisfaction.

Surgical Treatment of Subungual Squamous Cell Carcinoma by Wide Excision of the Nail Unit and Skin Graft Reconstruction: An Evaluation of Treatment Efficiency and Outcomes

Importance

The best surgical treatment modalities for subungual squamous cell carcinoma (SUSCC) without bone invasion need to be determined. The limited available data on Mohs micrographic surgery do not demonstrate its use as a standard procedure. A previous study in a limited series of patients has shown that wide surgical excision of the nail unit was associated with a low rate of recurrence.

Objectives

To confirm the efficiency of wide surgical excision of the nail unit with full-thickness skin graft reconstruction on a series of patients with SUSCC with an extended follow-up and to evaluate short- and long-term postoperative morbidity and patient satisfaction.

Design, Setting, and Participants

A consecutive series of 55 patients with biopsy-proven SUSCC without bone invasion treated by wide surgical excision of the nail unit followed by full-thickness skin graft reconstruction from January 1, 2000, to August 31, 2012 were included. After a minimum follow-up of 5 years, the recurrences were collected from the referring physicians. Statistical analysis was conducted from January 1 to June 30, 2016.

Main Outcomes and Measures

Demographic data, pathologic characteristics of tumors, postoperative follow-up, and recurrences were collected from medical records. Patients' satisfaction with surgery, quality of life, and delayed postoperative morbidity (functional outcome and sensory disorders) were assessed from a questionnaire mailed to patients and physicians.

Results

Among the 55 patients (23 women and 32 men; mean age, 64 years), the mean follow-up was 6.6 years (range, 5.0-11.2 years), with a minimum follow-up of 5 years. Fifty-two questionnaires (95%) were returned. Two recurrences were observed. Minor early postoperative complications, such as graft infection and delayed wound healing, were seen in 6 patients; 8 patients experienced severe pain. Late postoperative complications included hypersensitivity to mechanical shocks (39 of 51 patients [76%]), mildly increased sensitivity to cold (38 of 51 patients [75%]), loss of fine touch sensation (17 of 35 patients [49%]), and epidermal inclusion cysts (9 of 51 patients [18%]). Most patients were very satisfied with cosmetic and global outcomes of the surgery.

Conclusions and Relevance

Total excision of the nail unit followed by a full-thickness skin graft is a safe and efficient treatment for SUSCC without bone involvement, with satisfying cosmetic and functional outcomes.

Epidemiology of onychomycosis in Serbia: a laboratory-based survey and risk factor identification

Onychomycosis is a fungal infection of the fingernails and/or toenails caused by dermatophytes, yeasts and non-dermatophyte moulds. The epidemiology of onychomycosis in Serbia is yet to be fully established. This epidemiological study was aimed at evaluating the epidemiology of onychomycosis in a sample of the Serbian patients at risk of onychomycosis, to determine the fungal aetiological agents and to identify the possible risk factors. The study population included 374 patients from six centres in Serbia with suspected onychomycosis. Demographic data, data about comorbidities, lifestyle, clinical aspects of onychomycosis, trauma, excessive perspiration and personal and family history of previous onychomycosis were studied. Laboratory confirmation of diagnosis was done by direct microscopy, fungal culture and PCR. Diagnosis of onychomycosis was confirmed in 50.8% of patients, who tested positive to at least one laboratory test (direct microscopy, fungal culture or PCR). Trichophyton rubrum was predominant both on toenails (85.98%) and on fingernails (38.46%). Independent risk factors for onychomycosis were: old age (OR = 2.285; P < 0.001), family history of previous onychomycosis and/or tinea pedis (OR = 2.452; P = 0.005), excessive perspiration (OR = 2.165; P = 0.002) and higher degree of hyperkeratosis (OR = 1.755; P = 0.020). This is a first epidemiological study of onychomycosis from Serbia.

Clinical study of Dermatophyte Test Strip, an immunochromatographic method, to detect tinea unguium dermatophytes

The Dermatophyte Test Strip visualizes mycotic antigens by immunochromatography. It allows easy and fast detection of dermatophytes. A multicenter, single-arm, comparative clinical study was designed to evaluate the capacity of Dermatophyte Test Strip to detect dermatophytes in suspected tinea unguium specimens in comparison with direct microscopy and polymerase chain reaction (PCR). Signed consent was obtained from 222 subjects and all subjects completed the study. With the Dermatophyte Test Strip, dermatophytes were detected in 201 of 222 (90.5%) specimens but not in 21 of 222 (9.5%) specimens. With direct microscopy, dermatophytes were detected in 170 of 222 (76.6%) specimens but not in 52 of 222 (23.4%). Of the 45 specimens that showed inconsistent results between the two methods, PCR gave further results for 40 specimens, of which 37 (92.5%) specimens were positive and three (7.5%) were negative for dermatophytes. The positive concordance rate, negative concordance rate and overall concordance rate between the Dermatophyte Test Strip and direct microscopy were 81.1%, 66.7% and 79.7%, respectively. When inconsistent results were corrected using the results of PCR, these rates were 97.5%, 71.4% and 95.0%, respectively. When five specimens that could not be tested by PCR because no piece for the PCR test was left were excluded from analysis, these rates were 99.0%, 78.9% and 97.2%, respectively. The present results indicate good detection capacity of the Dermatophyte Test Strip. The Dermatophyte Test Strip provides a reliable, convenient and quick method to test for tinea unguium.

Diagnosis and Management of Onychomycosis Perspectives from a Joint Podiatric Medicine-Dermatology Roundtable

Onychomycosis is a fungal infection, and, as such, one of the goals of treatment should be eradication of the infective agent. Despite this, in contrast to dermatologists, many podiatric physicians do not include antifungals in their onychomycosis treatment plans. Before initiating treatment, confirmation of mycologic status via laboratory testing (eg, microscopy with potassium hydroxide preparation, histopathology with periodic acid-Schiff staining, fungal culture, and polymerase chain reaction) is important; however, more podiatric physicians rely solely on clinical signs than do dermatologists. These dissimilarities may be due, in part, to differences between specialties in training, reimbursement patterns, or practice orientation, and to explore these differences further, a joint podiatric medicine-dermatology roundtable was convened. In addition, treatment options have been limited owing to safety concerns with available oral antifungals and relatively low efficacy with previously available topical treatments. Recently approved topical treatments-efinaconzole and tavaborole-offer additional options for patients with mild-to-moderate disease. Debridement alone has no effect on mycologic status, and it is recommended that it be used in combination with an oral or topical antifungal. There is little to no clinical evidence to support the use of lasers or over-the-counter treatments for onychomycosis. After a patient has achieved cure (absence of clinical signs or absence of fungus with minimal clinical signs), lifestyle and hygiene measures, prophylactic/maintenance treatment, and proactive treatment for tinea pedis, including in family members, may help maintain this status.

Dermoscopic patterns in patients with a clinical diagnosis of onychomycosis-results of a prospective study including data of potassium hydroxide (KOH) and culture examination

Background:

Onychomycosis is the most common nail disease, representing 50% of cases affecting the nail apparatus. The diagnosis is made by clinical examination along with the KOH exam of the nail and culture of the sample. However, not all dermatologists have access to a mycology lab.

Objective:

To determine the correlation between KOH examination and dermoscopic patterns in patients with clinical diagnosis of onychomycosis.

Patients/Methods:

A descriptive, open, observational, prospective, cross-sectional study of 178 patients with clinical suspicion of onychomycosis was conducted. All patients underwent clinical examination, dermoscopy with a DermLite PHOTO dermatoscope (3Gen, San Juan Capistrano, CA, USA), KOH assessment and culture analysis. The most frequent dermoscopic patterns were identified and their correlation with the clinical subtype of onychomycosis was analyzed.

Results:

The study included 178 patients with clinical suspicion of onychomycosis. Of these, 155 (87.1%) had positive direct KOH examination for onychomycosis. Eighty-seven patients (56.13%) presented with clinical onychomycosis pattern of total dystrophic onychomycosis (TDO), 67 (43.23%) with distal lateral subungual onychomycosis (DLSO), 1 (0.65%) with trachyonychia). Dermoscopic patterns of onychomycosis showed the following frequencies: the spiked pattern was present in 22 patients (14.19%), longitudinal striae pattern in 51 patients (32.9%) and linear edge pattern in 21 patients (13.55%). We identified a pattern described as “distal irregular termination” in 41 patients with TDO and 26 with DLSO.

Conclusions:

This is the fist study conducted in a Mexican population that uses dermoscopy as a diagnostic tool along with the KOH examination for the diagnosis of onychomycosis. Dermoscopy may be used as an important diagnostic tool when evaluating nail disease. However, it should not be used as the only diagnostic criteria for onychomycosis.

Onychomycosis in patients with chronic leg ulcer and toenail abnormalities

Nails have a limited number of reactive patterns to disease. Accordingly, toenail changes of different etiologies may mimic onychomycosis.

Screening for tinea unguium by Dermatophyte Test Strip

BACKGROUND

The direct microscopy, fungal culture and histopathology that are necessary for the definitive diagnosis of tinea unguium are disadvantageous in that detection sensitivity is affected by the level of skill of the person who performs the testing, and the procedures take a long time.

OBJECTIVES

The Dermatophyte Test Strip, which was developed recently, can simply and easily detect filamentous fungi in samples in a short time, and there are expectations for its use as a method for tinea unguium screening. With this in mind, we examined the detection capacity of the Dermatophyte Test Strip for tinea unguium.

METHODS

The presence or absence of fungal elements was judged by direct microscopy and Dermatophyte Test Strip in 165 nail samples obtained from residents in nursing homes for the elderly. Moreover, the minimum sample amount required for positive determination was estimated using 32 samples that showed positive results by Dermatophyte Test Strip.

RESULTS

The Dermatophyte Test Strip showed 98% sensitivity, 78% specificity, 84·8% positive predictive value, 97% negative predictive value and a positive and negative concordance rate of 89·1%. The minimum sample amount required for positive determination was 0·002-0·722 mg.

CONCLUSIONS

The Dermatophyte Test Strip showed very high sensitivity and negative predictive value, and was considered a potentially useful method for tinea unguium screening. Positive determination was considered to be possible with a sample amount of about 1 mg.

Rapid detection of dermatophytes and Candida albicans in onychomycosis specimens by an oligonucleotide array

Background

Onychomycosis is a fungal infection of nails, leading to the gradual destruction of the nail plate. Treatment of onychomycosis may need long-time oral antifungal therapy that can have potential side effects, thus accurate diagnosis of the disease before treatment is important. Culture for diagnosis of onychomycosis is time-consuming and has high false-negative rates. To expedite the diagnosis, an oligonucleotide array, based on hybridization between immobilized oligonucleotide probes and PCR products, for direct detection of dermatophytes and Candida albicans in clinical specimens was evaluated.

Methods

Species-specific oligonucleotide probes designed from the internal transcribed spacer (ITS) regions of the rRNA gene were immobilized on a nylon membrane. The assay procedures consisted of PCR amplification of the ITS using universal primers, followed by hybridization of the digoxigenin-labeled amplicons to probes on the array. Thirty two nail samples (29 patients) were analyzed by the array, and the results were compared with those obtained by culture. Array-positive but culture-negative samples were confirmed by cloning and re-sequencing of the amplified ITS and by reviewing patient’s clinical data. The total recovery of culture and confirmed array-positive but culture-negative results was considered 100% and was used for performance evaluation of both methods.

Results

Concordant results were obtained in 21 samples (10 positives and 11 negatives) by both methods. Eleven samples were array-positive but culture-negative; among them, 9 samples were considered true positives after discrepant analysis. Comparing with culture, the array had significantly higher sensitivity [100% (95% CI 82.2% −100%) vs 52.6% (28.9% −75.5%), p <0.001] and negative predictive value [100% (71.3% −100%) vs 59.1% (36.4% −79.3%), p <0.05), while no significant differences were observed in specificity (84.6% vs 100%, p =0.48) and positive predictive value (90.5% vs 100%, p =1.0). The whole procedures of the array were about 24 h, whilst results from culture take 1 to 3 weeks.

Conclusions

The array offers an accurate and rapid alternative to culture. Rapid diagnosis can expedite appropriate antifungal treatment of onychomycosis. However, the single site nature of this study conducted at a referral hospital invites caution.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0581-5) contains supplementary material, which is available to authorized users.

Confocal laser scanning microscopy as a new valuable tool in the diagnosis of onychomycosis - comparison of six diagnostic methods

Onychomycosis is common and can mimic several different nail disorders. Accurate diagnosis is essential to choose the optimum antifungal therapy. The aim of this study was to evaluate the use of confocal laser scanning microscopy (CLSM) and optical coherence tomography (OCT) as new non-invasive diagnostic tools in onychomycosis and to compare them with the established techniques. In a prospective trial, 50 patients with suspected onychomycosis and 10 controls were examined by CLSM and OCT. Parallel KOH preparation, culture, PAS-staining and PCR were performed. PCR showed the highest sensitivity, followed by CLSM, PAS and KOH preparation. OCT offered the second best sensitivity but displayed the lowest specificity. CLSM and KOH preparation showed a high specificity and CLSM offered the best positive predictive value, similar to KOH preparation and OCT. Fungal culture showed the lowest sensitivity and the worst negative predictive value, yet culture and PCR are the only techniques able to identify genus and species. In summary, CLSM was comparable to PAS staining and superior to KOH preparation. Due to the low specificity we assess OCT not as appropriate. In the differentiation of species PCR outplays the fungal culture in terms of time and sensitivity.

The presence of fungi on contact electrical stimulation electrodes and ultrasound transducers in physiotherapy clinics

OBJECTIVES

To evaluate the presence of fungi on contact electrodes and ultrasound transducers from physiotherapy clinics.

DESIGN

Quantitative study conducted at the Laboratory of Microbiology and Immunology, Faculty of Health Sciences and Technology of Piauí - NOVAFAPI, Teresina, Brazil.

SETTING

Sample collection was performed in 10 clinics (20 ultrasound transducers and 20 contact electrodes).

MAIN OUTCOME MEASURES

Swabs were soaked with saline solution, inoculated in culture and incubated for filamentous fungi and yeast growth.

RESULTS

Fourteen taxons were identified: Acremomium hyalinulum (Sacc.), Aspergillus terreus, Candida albicans, Cladosporium cladosporioides, Cladosporium elatum, Cladosporium oxysporum, Cladosporium sphaerospermum, Cladosphialophora bantiana, Curvularia clavata, Curvularia senegalensis, Fusarium oxysporum, Penicillium decumbens, Scopulariopsis candida and Sporothrix schenckii. Aspergillus terreus, Cladosporium oxysporum, Sporothrix shenckii and Candida albicans were found most often on contact electrodes, and Penicillium decumbens and Cladosporium cladosporioides were found most often on ultrasound transducers.

CONCLUSION

Fungi were found on all of the contact electrodes and ultrasound transducers. Physiotherapy professionals need to improve the disinfection procedures for this equipment.