A Retrospective Review of Diagnostic Testing for Onychomycosis of the Foot

2015 ◽  
Vol 105 (6) ◽  
pp. 503-508 ◽  
Author(s):  
Nell Blake ◽  
Junjia Zhu ◽  
Giselle Hernandez ◽  
Paul Joseph Juliano

Background Onychomycosis is a fungal infection of the nail that can be caused by dermatophytes, yeasts, or nondermatophyte molds. To diagnose onychomycosis, a clinician must use the patient's history, physical findings, and diagnostic testing, which can include calcofluor white/potassium hydroxide (KOH) mount, fungal culture (FC), and periodic acid–Schiff (PAS) stain. Some insurance companies require authorization for antifungal medication and request laboratory results to confirm infection. We sought to compare the reliability of KOH, PAS, and FC diagnostic results for confirmation of fungal disease, to determine the sensitivity and specificity of each test, and to investigate the cost of each test. In addition, we statistically observed the relationship between the test results and demographic variables. Methods Toenail clippings were obtained from 108 patients clinically diagnosed as having onychomycosis. Diagnostic tests were then performed on each sample; the results were obtained from medical records. Results For PAS, KOH, and FC, 60.2%, 43.5%, and 39.8% of results, respectively, were positive. Agreement for each pair of tests was slightly higher for FC and KOH. Sensitivities for KOH and PAS were 0.64 and 0.79, respectively. Specificity was 0.79 for KOH and 0.54 for PAS. Both PAS and KOH had a higher percentage of positive test results for men than for women. Conclusions Of the three tests evaluated, PAS gives the most consistent positive results and has the highest sensitivity. Therefore, PAS should be considered as the best test to verify clinically significant onychomycosis.

2017 ◽  
Vol 22 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Aditya K. Gupta ◽  
Sarah G. Versteeg ◽  
Neil H. Shear

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.


2005 ◽  
Vol 95 (3) ◽  
pp. 258-263 ◽  
Author(s):  
Jeffrey M. Weinberg ◽  
Evelyn K. Koestenblatt ◽  
Maureen B. Jennings

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)


2017 ◽  
Vol 3 (2) ◽  
pp. 205511691773116
Author(s):  
Rodolfo Oliveira Leal ◽  
Kenny Simpson ◽  
Mélanie Fine ◽  
Jean-Charles Husson ◽  
Juan Hernandez

Case summary This report describes a 4-year-old cat with chronic intermittent haematochezia and faecal incontinence of 7 months’ duration. Investigation revealed severe colonic multifocal mucosal ulcerations and infiltration of the mucosal lamina propria by large numbers of periodic acid–Schiff-positive macrophages. Fluorescence in situ hybridisation analysis of colonic biopsies revealed multifocal clusters of intracellular Escherichia coli. Treatment with fluoroquinolones for 6 weeks led to a complete resolution of clinical signs. Relevance and novel information The findings reveal that mucosally invasive E coli can also be associated with granulomatous colitis in cats and indicate the need for diagnostic testing of mucosal samples for E coli and other infectious agents.


2021 ◽  
Author(s):  
Yayu Guo ◽  
Huimin Xu ◽  
Hongyang Wu ◽  
Weiwei Shen ◽  
Jinxing Lin ◽  
...  

Abstract Understanding the changing patterns of vascular cambium during seasonal cycles is crucial to reveal the mechanisms that control cambium activity and wood formation, but this area has been underexplored, especially in conifers. Here, we quantified the changing cellular morphology patterns of cambial zones during the active, transition and dormant stages. With the help of toluidine blue and periodic acid Schiff staining to visualize cell walls and identify their constituents, we observed decreasing cambial cell layers, thickening of newly formed xylem cell walls and increased polysaccharide granules in phloem from June to the following March over the course of our collecting period. Pectin immunofluorescence showed that dormant stage cambium can produce highly abundant de-esterified homogalacturonan and (1–4)-β-D-galactan epitopes, while active cambium can strong accumulate high methylesterified homogalacturonan. Calcofluor white staining and confocal Raman spectroscopy analysis revealed regular changes in the chemical composition of cell walls, such as relative lower cellulose deposition in transition stage in vascular cambium, and higher lignin accumulation was found in dormant stage in secondary xylem. Moreover, RT-qPCR analysis suggested that various IAA (Aux/IAA protein), CesA, CslA and HDZ genes, as well as NAC, PME3 and PME4, may be involved in cambium activities and secondary xylem formation. Taken together, these findings provide new information about cambium activity and cell differentiation in the formation, structure, and chemistry in conifers during the active–dormant transition.


Author(s):  
Alexander K.C. Leung ◽  
Joseph M. Lam ◽  
Kin F. Leong ◽  
Kam L. Hon ◽  
Benjamin Barankin ◽  
...  

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.


2017 ◽  
Vol 29 (3) ◽  
pp. 269-277 ◽  
Author(s):  
Luis E. Rodríguez-Tovar ◽  
Alejandra Villarreal-Marroquín ◽  
Alicia M. Nevárez-Garza ◽  
Uziel Castillo-Velázquez ◽  
Heidi G. Rodríguez-Ramírez ◽  
...  

Encephalitozoon cuniculi is an important microsporidian pathogen that is considered an emergent, zoonotic, and opportunistic. It infects both domestic and laboratory rabbits, generating severe chronic interstitial and granulomatous nephritis with fibrosis and granulomatous encephalitis. Encephalitozoonosis is diagnosed in paraffin-embedded sections by examining the spores in the host tissues. The spores are difficult to observe when the samples are stained with hematoxylin and eosin (H&E), particularly when there is an inflammatory reaction and tissue damage. The spores are easily mistaken for other microorganisms, such as fungi (yeasts), protozoa, and bacteria. In our study, we used kidney samples from E. cuniculi–positive rabbits and employed 14 recommended histologic stains for detecting microsporidia spores: alcian blue, calcofluor white, Giemsa, Gram, Grocott, H&E, Luna, Luxol fast blue, Masson trichrome, modified trichrome stain (MTS), periodic acid–Schiff reaction (PAS), Van Gieson, Warthin–Starry (WS), and Ziehl–Neelsen (ZN).We concluded that MTS and Gram stain, detected by light microscopy, and calcofluor white stain, detected by ultraviolet light microscopy, are the best stains for detecting spores of E. cuniculi in paraffin-embedded tissues from infected rabbits. These stains were superior to WS, ZN, Giemsa, and PAS for identifying spores without background “noise” or monochromatic interference. Also, they allow individual spores to be discerned in paraffin-embedded tissues. MTS allows observation of the polar tube, polaroplast, and posterior vacuole, the most distinctive parts of the spore.


2020 ◽  
Vol 48 (1) ◽  
pp. 030006051989803 ◽  
Author(s):  
Leilei Gu ◽  
Bin Wang ◽  
Lu Liu ◽  
Qiaorong Gan ◽  
Xiaolong Liu ◽  
...  

Hepatic fibrinogen storage disease is a rare autosomal dominant genetic disorder characterized by hypofibrinogenemia, as well as the retention of variant fibrinogen within the hepatocellular endoplasmic reticulum. Here, we describe an asymptomatic 4-year-old boy with abnormal liver function test results and unexpected hypofibrinogenemia. Liver biopsy showed circular eosinophil inclusion bodies in the hepato-cytoplasm. Immunostaining results of eosinophil inclusion bodies were positive for fibrinogen. Following pretreatment with diastase, the inclusion bodies failed to stain with the periodic acid–Schiff technique; moreover, immunostaining results were positive for fibrinogen, but negative for alpha-1-antitrypsin. Genetic analysis identified a heterozygous missense mutation c.1201C > T (p. Arg401Trp) within the fibrinogen γ-chain ( FGG) gene and an additional single nucleotide polymorphism c.-58 A > G within the 5′-untranslated region of the fibrinogen Aα-chain ( FGA) gene. Thus, the patient was diagnosed with hepatic fibrinogen storage disease. Our results indicate that, for patients who exhibit chronic liver disease with unexpected hypofibrinogenemia, hepatic fibrinogen storage disease should be considered in the differential diagnosis. Moreover, our findings emphasize the importance of molecular diagnosis in patients with cryptogenic liver disease.


2018 ◽  
Vol 7 (2) ◽  
pp. 45
Author(s):  
Dhelya Widasmara

ONYCHOMYCOSIS FINGER AND TOE NAIL BY Cryptococcus laurentii, Trychophyton verrucosum, and Candida sp  Dhelya Widasmara, Diane Tantia SariDepartment of Dermatology and Venereology, Medical Faculty, Brawijaya Universitydr.Saiful Anwar Regional Public Hospital, Malang, IndonesiaEmail: [email protected] AbstractIntroduction : Onychomycosis is included in most common nail disease and contributes to 50% of onychodystropic events. So far, there are rare cases of onychomycosis due to Cryptoccus laurentii and Trychophyton verrucosum. Case : Woman, 54 y.o, complaining of brittle nails and cracked on the soles of the feet and hands since 6 months ago. Patients have daily habits to go to rice fields without gloves and footwear, and rarely wash their hands and feet after the rice fields. Dermatologic examination of all unguium digiti manus and the right and left hand, obtained discolorization of yellow and white and some blackish, subungual hyperkeratosis, onikolisis, and onikodistrofik. In plantar dekstra et sinistra, obtained erythema plaque, multiple, irregular shape, varied size, with rough skuama, as well as multiple yellow and white hyperkeratotic plaques with fissures. A 20% KOH examination of a hand and foot nail, both of which obtained a long septae hyphae. Periodic Acid-Schiff coloration (PAS) obtained a description of spores. Fungal culture from fingernail obtained growth of Criptococcus laurentii and Trichophyton spp., culture of toenails obtained growth Trichophyton verrucosum and Candida sp. Patients were treated with itraconazole tablet dose of 2x200mg / day dose for a week every month, gentamicin ointment, and 20% urea cream, myologic improvement after 4 weeks of therapy. Discussion : The incidence of onychomycosis due to Cryptoccus laurentii and Trychophyton verrucosum is still rare. The predisposing factor of infection in these patients is due to the patient's habitual contact with the paddy fields. Keywords : onychomycosis, Cryptococcus laurentii, Trychophyton verrucosum


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