Utility of Histopathologic Analysis in the Evaluation of Onychomycosis

2005 ◽  
Vol 95 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Jeffrey M. Weinberg ◽  
Evelyn K. Koestenblatt ◽  
Maureen B. Jennings
Keyword(s):  
Potassium Hydroxide ◽  
Periodic Acid ◽  
False Negative ◽  
Nail Plate ◽  
Fungal Culture ◽  
Periodic Acid Schiff ◽  
Negative Results ◽  
False Negative Results ◽  
Histopathologic Analysis ◽  
Dermatophyte Infection

Onychomycosis is a common problem seen in clinical practice. Given the differential diagnosis of dystrophic nails, it is helpful to obtain a definitive diagnosis of dermatophyte infection before initiation of antifungal therapy. Potassium hydroxide preparation and fungal culture, which are typically used in the diagnosis of these infections, often yield false-negative results. Recent studies have suggested that nail plate biopsy with periodic acid–Schiff stain may be a very sensitive technique for the diagnosis of onychomycosis. In this article, we review the literature on the utility of histopathologic analysis in the evaluation of onychomycosis. Many of these studies indicate that biopsy with periodic acid–Schiff is the most sensitive method for diagnosing onychomycosis. We propose that histopathologic examination is indicated if the results of other methods are negative and clinical suspicion is high; therefore, it is a useful complementary technique in the diagnosis of onychomycosis. (J Am Podiatr Med Assoc 95(3): 258–263, 2005)

scholarly journals Sensitivity of PAS histopathology stain for the diagnosis of onychomycosis at multicenter teaching hospitals, Pakistan.

2019 ◽  
Vol 26 (08) ◽  
pp. 1213-1217
Author(s):  
Muhammad Wajid Khurshid Sipra ◽  
Zahid Mehmood Akhtar ◽  
Tayyaba Batool
Keyword(s):  
Periodic Acid ◽  
False Negative ◽  
Nail Plate ◽  
Teaching Hospitals ◽  
Periodic Acid Schiff ◽  
Cross Sectional ◽  
Medical College ◽  
Negative Results ◽  
False Negative Results ◽  
Disease Study

The aim of this study was to determine the sensitivity of Periodic acid –Schiff (PAS) staining an early and quick effective diagnostic test of nail clipping with routine tests in the diagnosis of Onychomycosis. Background: The routine gold standard for diagnosis of fungal nail infections has been direct microscopy (KOH mount) and mycological culture which often yield delayed or weak/false negative results. However recent studies have suggested that nail plate biopsy using PAS stain is rapid method of detection that grasped the diagnosis and manage the disease. Study Design: Cross sectional descriptive study. Setting: 320 clinical diagnosed cases of onychomycosis performed at Department of Microbiology, Quaid-e-Azam Medical College Bahawalpur and Department of Histopathology King Edward medical University Lahore. Period: January 2012 to August 2018. Materials and Methods: The parameter looked in the sent investigation were histopathology PAS stain, mycological culture and microscopy. Presences of intensely stained reddish dots or threads like structures in between the cells of nail plate were considered to be positive results on histopathology with periodic acid Schiff (PAS). The microscopic study showed hyphae or spores and growth of organism concluded by morphological colony characteristics on Sabouraud's dextrose agar (SDA) periodically after 4 weeks. Result: out of total 320 cases, 81.25% was positive for histopathology PAS stain. Culture positivity was 60% and KOH mount recovered 52.5% positive. The combination of PAS stain and culture results showed 90.62% while Culture and KOH were 62.5% in nail clipping specimen. Conclusion: Histopathological PAS technique was found to be more effective than other laboratory methods for the diagnosis of Onychomycosis.

Onychomycosis: An Updated Review

2020 ◽  
Vol 14 (1) ◽  
pp. 32-45
Author(s):  
Alexander K.C. Leung ◽  
Joseph M. Lam ◽  
Kin F. Leong ◽  
Kam L. Hon ◽  
Benjamin Barankin ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Therapeutic Option ◽  
English Literature ◽  
Periodic Acid ◽  
Nail Plate ◽  
Clinical Manifestations ◽  
Trichophyton Mentagrophytes ◽  
Treatment Modalities ◽  
Fungal Culture ◽  
Periodic Acid Schiff

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.

Examination Of Nail Clippings For Onychomycosis: Histologic Observations With Microbiologic Correlations

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
S Liaquat ◽  
A Bryson ◽  
M Mochel
Keyword(s):  
Periodic Acid ◽  
Nail Plate ◽  
Fungal Growth ◽  
Common Disease ◽  
Consecutive Series ◽  
Fungal Culture ◽  
Culture Methods ◽  
Periodic Acid Schiff ◽  
Fungal Organisms ◽  
Histologic Changes

Abstract Introduction/Objective Appropriate management of onychomycosis, the most common disease of the nail unit, depends on accurate and timely diagnosis. Histologic evaluation of nail clippings, paired with histochemical techniques such as Periodic acid-Schiff (PAS), is a rapid, sensitive method for diagnosis of onychomycosis. While studies have compared testing modalities for onychomycosis, few have systematically evaluated histologic changes of the nail plate and correlated findings with concomitant microbiologic culture. Methods A consecutive series of nail clipping specimens between July 2016 to July 2019 from our institution were evaluated. Clinical data were collected, H&E and PAS stains were examined for histologic nail plate alterations and fungal presence, morphology, location, and abundance. Concurrent culture results were also collected and correlated. Results Histologic slides, including PAS, of nail clippings were evaluated from 131 patients (median age 57, 65% female). 53 cases (40%) were positive for fungal organisms by PAS stain: 26 cases showed diffuse fungal involvement, while 27 cases showed focal fungal involvement, limited to one 200x field. Of the PAS-positive cases, 47 cases showed predominantly hyphae and 6 cases showing predominantly yeast-like morphology. Nail plate histologic changes associated with PAS positivity included parakeratosis (p= 0.0071) and neutrophilic aggregates (p=0.0017). Of the total cases evaluated by histology, 67 cases had concomitant cultures performed, with 17 of these cases (25%) positive for fungal growth. Of the 23 PAS-positive cases with simultaneous culture sent, only 9 cases (39%) were positive for fungal growth. Conversely, of the 44 PAS-negative cases with simultaneous culture sent, 8 cases (18%) were positive for fungal growth. For cases positive by both PAS and fungal culture, significant correlations between fungal morphology on PAS and microbiologic speciation were not observed. Conclusion While PAS stains appear overall more sensitive for onychomycosis, both PAS and culture methods are falsely negative in a significant number of cases. In cases of high clinical suspicion for onychomycosis, consideration of employing more than one testing modality is recommended. Of note, histologic examination may reveal nail plate changes associated with fungal infestation, including nail plate parakeratosis and neutrophilic aggregates.

Confirmatory Testing Prior to Initiating Onychomycosis Therapy Is Cost-Effective

2017 ◽  
Vol 22 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Aditya K. Gupta ◽  
Sarah G. Versteeg ◽  
Neil H. Shear
Keyword(s):  
Potassium Hydroxide ◽  
Periodic Acid ◽  
Diagnostic Testing ◽  
Nail Plate ◽  
Cost Savings ◽  
Public Domain ◽  
Confirmatory Test ◽  
Periodic Acid Schiff ◽  
Confirmatory Testing ◽  
The Cost

Background: Onychomycosis can be investigated by sampling. Information gleaned includes nail bed involvement, nail plate penetration, fungal viability, and species identification. Testing samples can confirm a diagnosis. While diagnostic testing is considered useful in directing therapy, a substantial number of clinicians do not confirm diagnosis prior to treatment. Objectives: The aim of this study is to quantify the benefit of confirmatory testing prior to treating toenail onychomycosis. Methods: The cost of mycological cure (negative potassium hydroxide and negative culture) and the cost-effectiveness of confirmatory testing were determined using the average cost of potassium hydroxide (KOH), culture, periodic acid–Schiff (PAS), efinaconazole, ciclopirox, terbinafine, and itraconazole. Costs were obtained through literature searches, public domain websites, and telephone surveys to local pharmacies and laboratories. To represent the potential risks of prescribing onychomycosis treatment, the costs associated with liver monitoring, potential life-threatening adverse events, and drug-drug interactions were obtained through public domain websites, published studies, and product inserts. Results: PAS was determined to be the most sensitive confirmatory test and KOH the least expensive. The overall cost of an incorrect diagnosis (no confirmatory test used) ranged between $350 and $1175 CAD per patient for treatment of 3 infected toenails. Comparatively, performing confirmatory testing prior to treatment decreases the overall cost to $320 to $930, depending on the therapy, physician, and test. Conclusions: It is preferred to diagnose onychomycosis prior to treatment. Furthermore, there are cost savings when confirmatory testing is performed before initiating treatment with both topical and oral antifungals in Canada.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

Detection of Streptococcus pneumoniae in Sputum Samples by Real- Time PCR.

2020 ◽  
Vol 18 ◽  
Author(s):  
Pegah Shakib ◽  
Mohammad Reza Zolfaghari
Keyword(s):  
Streptococcus Pneumoniae ◽  
Real Time ◽  
Real Time Pcr ◽  
False Negative ◽  
Cross Sectional Study ◽  
Laboratory Culture ◽  
Cross Sectional ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Method

Background: Conventional laboratory culture-based methods for diagnosis of Streptococcus pneumoniae are time-consuming and yield false negative results. Molecular methods including real-time (RT)-PCR rapid methods and conventional PCR due to higher sensitivity and accuracy have been replaced instead traditional culture assay. The aim of the current study was to evaluate lytA gene for detection of Streptococcus pneumoniae in the cerebrospinal fluid of human patients with meningitis using real-time PCR assay. Material and Methods: In this cross-sectional study, a total of 30 clinical specimens were collected from patients in a period from September to December 2018. In order to evaluate the presence of lytA gene, conventional and real-time PCR methods were used without culture. Results: From 30 sputum samples five (16.66%) isolates were identified as S. pneumoniae by lytA PCR and sequencing. Discussion: In this research, an accurate and rapid real-time PCR method was used, which is based on lytA gene for diagnosis of bacteria so that it can be diagnosed. Based on the sequencing results, the sensitivity for detection of lytA gene was 100% (5/5).

Sign in / Sign up

Export Citation Format

Share Document