Microscopic examination of normal nail clippings

Nail Clipping with PAS Stain and Correlation with Fungi Isolated in Culture: A Valuable Exchange in the Diagnosis of Onychomycosis

Introduction

The etiological agents of onychomycosis are dermatophyte fungi, nondermatophyte filamentous fungi (NDFF), and yeasts. Nail clippings are an accurate tool for diagnosing onychomycosis. The objective of this study was to correlate the characteristics of fungi observed in nail clipping examinations with the results for agents isolated in culture, indicating whether the fungus found on microscopy is a dermatophyte, NDFF, or yeast.

Methods

An observational descriptive study of onychomycosis nail clippings stained with PAS comparing culture results with microscopic criteria of fungi morphology, arrangement/orientation, and location of organisms in the nail and presence of neutrophils, serous lakes, and bacterial colonies was conducted.

Results

Thirty-three nail clippings from 29 participants were analyzed. A statistically significant correlation (p < 0.05) was found between smooth/thin/long hyphae with a "combed" pattern and dermatophyte agents (sensitivity 89.4%, specificity 91.5%), and between irregular/thick/short anarchic distributed hyphae and nondermatophytes (sensitivity 61.5%, specificity 89.4%). No statistical association with region where fungi were in the nail or with the presence of neutrophils, serous lakes or bacteria was found. Small, rounded, yeast-like organisms correlated with Candida infection.

Conclusions

Although not a substitute for culture, microscopic analysis of fungal structures offers good accuracy for differentiating agents of onychomycosis.

Histopathological Findings in Nail Clippings With Periodic Acid-Schiff-Positive Fungi

BACKGROUND

Periodic acid-Schiff (PAS) staining of nail clippings is an adjunct diagnostic tool for onychomycosis.

OBJECTIVE

To detect histopathological findings as clues to the presence of PAS-positive (+) fungal elements in nail clippings.

METHODS

Four hundred sixteen consecutive nail clippings suspected of onychomycosis were stained with hematoxylin and eosin, and with PAS stains. All cases were studied histopathologically. The clinical files of the cases with neutrophils were reviewed.

RESULTS

PAS+ staining for fungi were demonstrated in 159 (38%) of the nail clippings. Neutrophils, parakeratosis, plasma globules, and bacteria were observed in 43 (27%), 108 (67%), 80 (50%), and 80 (50%) of the PAS+ cases, respectively, and in 17 (6%), 109 (41%), 84 (32%) and 140 (54%) of the PAS- cases, respectively (P < 0.01). Neutrophils showed by far the highest specificity (93%), although with low sensitivity (27%) for the presence of PAS+ fungi. Among the 43 PAS+ and 17 PAS- specimens with neutrophils, only 1 (2.3%) and 3 (17%) had overt psoriasis, respectively.

CONCLUSION

Neutrophils in nail clippings may serve as a clue for onychomycosis. PAS staining with neutrophils is not necessarily associated with psoriasis.

Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations

BACKGROUND AND OBJECTIVES

While optical imaging is a useful technique to quantitate morphological differences and treatment effects, comparative investigations of the various techniques are lacking. This study aimed at evaluating intermethod agreement, reliability, and technical limitations of wide-field microscopy (WFM), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) for morphometry by assessing fractionally ablated nail tissue.

STUDY DESIGN/MATERIALS AND METHODS

Fifty healthy nail clippings were processed with a fractionated CO₂ -laser (20 mJ/microbeam, density 15%), measured with calipers, and imaged using WFM, OCT, and RCM. Images were assessed for nail plate thickness, micropore dimensions, degree of poration, and artifacts. Repeated measurements (2-5) were taken to evaluate method repeatability using Cronbach's α and coefficients of variation (CoV), and estimate the intermethod correlation through linear correlation assessment (Pearson correlation coefficient [PCC]), ranked correlation (Kendall's tau; tau-c), and intraclass correlation (Shrout-Fleiss reliability coefficient; ICC).

RESULTS

The repeatability varied substantially between methods and target measurements. The level of intermethod agreement for thickness measurements performed with calipers, WFM, and OCT was high (tau-c ≥ 0.7; ICC ≥ 0.8; PCC ≥ 0.9). RCM could only image 28 out of 50 samples due to its limited penetration depth. OCT demonstrated the highest repeatability of all imaging techniques (CoV 4-7%) and nail thickness showed the highest measurement reliability (α = 0.92). Micropore dimensions correlated strongest between OCT and RCM (tau-c/ICC/PCC ≥ 0.5). All modalities were prone to artifacts, which may have adversely affected measurement variation and intermethod agreement.

CONCLUSION

Intermethod agreement and reliability appear to be highly dependent on the specific modality and target measurement. To reap the benefits of each technique while mitigating their limitations, an integrated approach to optical imaging is recommended. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Microscopic Examination of Nail Clippings from Patients with Palmoplantar Pustulosis

This study describes the clinical characteristics and microscopic findings of nails from 25 patients with palmoplantar pustulosis.

Methods

This is a cross-sectional study of adult patients with clear-cut palmoplantar pustulosis. Onychodystrophy severity was evaluated in fingernails using the nail psoriasis severity index (NAPSI). A fragment of the most dystrophic fingernail was collected from each patient and submitted to routine histotechnical processing. The following microscopic parameters were evaluated: nail plate and subungual region thickness, presence or absence of parakeratosis, number of layers of parakeratosis, and presence of neutrophils, serous lakes, bacteria, blood, and fungi.

Results

Twenty-one patients (84%) presented onychodystrophy with a mean NAPSI score of 12.67. The most common nail change was pitting (76.19% of patients). On average, nail plate thickness and subungual region thickness measured 0.42 and 0.14 mm, respectively. Neutrophils and fungi were not observed, but serous lakes were found in 4.7%, bacteria in 28.57%, blood in 4.76%, and parakeratosis in 19.05% of the patients.

Conclusions

although palmoplantar pustulosis is a disease with great amounts of neutrophils in the epidermis, those cells were not found in the nail clippings studied herein. Furthermore, when clinical aspects and microscopic findings of palmoplantar pustulosis are compared to those of similar studies in psoriasis vulgaris, they show different characteristics.

Neutrophils in Nail Clipping Histology: A Retrospective Review of 112 Cases

BACKGROUND

Nail clipping histology is more sensitive than mycology for detecting nail fungi. However, in the absence of fungi, established diagnostic clues for this and other nail dystrophy causes are lacking, namely for nail psoriasis. Neutrophils have been reported in onychomycosis and nail psoriasis samples but have been insufficiently characterized.

OBJECTIVES

The aim of this paper is to differentiate neutrophil-containing nail clipping samples in nail psoriasis and onychomycosis regarding histology.

METHODS

We performed a 3-year retrospective review of all nail clipping test results included in our department's database and re-analyzed samples containing neutrophils.

RESULTS

In total,112 neutrophil-containing nail clipping samples were accounted. Onychomycosis was the commonest diagnosis (74.1%), followed by nail psoriasis (18.8%). Onychomycosis samples had more abundant neutrophils, more often arranged in collections (60.2%) (p = 0.002) and with smaller quantities of parakeratosis, in a lamellar distribution. In nail psoriasis, neutrophils were mostly aggregated (57.1%) with parakeratosis in all samples, in increased amounts, and showing no predominant pattern.

CONCLUSIONS

Neutrophils are present in both nail psoriasis and onychomycosis, warranting careful interpretation. However, less dense aggregates of neutrophils with more abundant parakeratosis are clues of nail psoriasis when all other fungal tests are negative.

Nail clipping in onychomycosis and comparison with normal nails and ungual psoriasis

BACKGROUND

Of all nail disorders seen in dermatology offices, half of them are due to onychomycosis. The main differential diagnosis is nail psoriasis. The objective of this study was to compare the microscopic findings, other than the presence of fungi, in the clipping of onychomycosis versus normal nails and nail psoriasis.

METHODS

Cross-sectional study of onychomycosis cases, analyzed by clipping and compared with data on normal nails and those with nail psoriasis.

RESULTS

Sixty-two onychomycosis samples were compared with 30 normal nails and 50 nails with psoriasis. In onychomycosis, measurement of subungual region, serous lakes, neutrophils and number of layers of parakeratosis are more intense than in psoriasis. Onychocariosis is less common in psoriasis, while bacteria are more frequent. The nail transition zone is more commonly blurred and irregular in onychomycosis.

CONCLUSION

Clipping helps in the differential diagnosis of onychomycosis and nail psoriasis and may be useful even when fungi are not found.

Clinical features and nail clippings in 52 children with psoriasis

BACKGROUND/OBJECTIVES

Nail clipping, the act of cutting the distal portion of a nail for microscopic analysis, can complement the diagnosis of skin diseases with nail involvement, such as psoriasis. This study aimed to describe histopathologic findings on 81 nails from 52 children and adolescents with skin psoriasis and to determine whether these changes correlated with the severity of skin and nail involvement.

METHODS

Children with psoriasis were enrolled in this cross-sectional study to obtain Psoriasis Area and Severity Index (PASI) and Nail Psoriasis Severity Index (NAPSI) scores. The most altered nails were processed using periodic acid-Schiff with diastase staining.

RESULTS

Fifty-two patients with a median age of 10.5 years were included. The median Nail Psoriasis Severity Index score of the 20 nails from these patients was 17 (range 3-80). The most common findings were pitting (94.2%), leukonychia (73.0%), and longitudinal ridges (63.5%). Eighty-one nail fragments were collected by clipping. Neutrophils were found in 6 samples (7.6%) and serous lakes in 15 (19%). Median nail plate thickness was 0.3 mm (range 0.1-0.63 mm). Patients whose nails had neutrophils had a higher median PASI score (6.1 vs 2.0, P = .03). Patients whose nails had serous lakes had higher median PASI (5.3 vs 1.9, P = .008) and NAPSI (median 45.0 vs 18.0, P = .006) scores.

CONCLUSION

There seems to be a correlation between some microscopic nail features in children with psoriasis and their PASI and NAPSI scores, so nail clippings from children with suspected psoriasis may help with diagnosis, especially in the presence of neutrophils, and in excluding onychomycosis.

Nail clipping in onychomycosis

Onychomycosis is the most prevalent onychopathy and it requires a correct early diagnosis. Currently, the diagnostic gold standard is the association of direct mycological test with culture; however, it shows variable sensitivity. The histopathological examination of the distal nail plate, called clipping, has shown to be an adjuvant in diagnosing onychomycosis. This is an easy-to-perform, relatively cheap examination that is little dependent of the examiner, rapidly provides results, has high sensitivity, and for patients it is painless and harmless.

Comparative microscopic analysis of nail clippings from patients with cutaneous psoriasis and psoriatic arthritis

BACKGROUND

The nail involvement in psoriasis is related to psoriatic arthritis and may represent a predictor of the disease.

OBJECTIVES

To analyze, through nail clipping, clinically normal and dystrophic nails of patients with cutaneous psoriasis and psoriatic arthritis.

METHODS

This is a cross-sectional multicenter study, conducted between August 2011 and March 2012. Patients were divided into four groups: patients with cutaneous psoriasis and onychodystrophy, patients with cutaneous psoriasis and clinically normal nails, patients with psoriatic arthritis and onychodystrophy and patients with psoriatic arthritis and clinically normal nails. We calculated NAPSI (Nail Psoriasis Severity Index) of the nail with more clinically noticeable change. After collection and preparation of the nail clipping, the following microscopic parameters were evaluated: thickness of the nail plate and subungual region, presence or absence of parakeratosis, serous lakes, blood, and fungi.

RESULTS

There were more layers of parakeratosis (p=0.001) and a greater thickness of the subungual region in patients with cutaneous psoriasis and onychodystrophy (p=0.002). Serous lakes were also more present in the same group (p=0.008) and in patients with psoriatic arthritis and normal nails (p=0.047). The other microscopic parameters showed no significant difference between normal and dystrophic nails or between patients with psoriatic arthritis or cutaneous psoriasis.

STUDY LIMITATIONS

Small sample size and use of medications.

CONCLUSIONS

Nail clipping is a simple and quick method to assess the nails of patients with nail psoriasis although does not demonstrate difference between those with joint changes or exclusively cutaneous psoriasis.

A Clinico-Mycological Study on Suspected Cases of Chromoblastomycosis: Challenges in Diagnosis and Management

INTRODUCTION

Verrucous plaques mimicking chromoblastomycosis are frequently seen in dermatology outpatient departments (OPD). However, no scientific evaluation has been carried out till date from eastern India. So this present endeavour is aimed at a thorough study of those cases to readdress the challenges in diagnosis and management in chromoblastomycosis from this part of the country.

AIM

The study is to observe the incidence of proved chromoblastomycosis cases from clinically mimicking conditions and to note therapeutic prospects by use of different antifungal agents.

MATERIALS AND METHODS

Twenty clinically suspected cases attending dermatology OPD were included in this study. Relevant histories were taken. Apart from routine hematological and biochemical investigations, scrapings from lesions were examined by direct microscopy with KOH wet mount, calcoflour white mount and fungal culture. Histopatholgical examination was also done. Any fungal growth was identified by growth characteristics and morphological features.

RESULTS

Sclerotic bodies were detected in five samples. Of them three were found to be culture positive. Two growths were identified as Fonsecaea pedrosoi and one as Cladosporium carrionii. Rest 12 cases were diagnosed as either lupus vulgaris (3 cases; 15%), atypical mycobacterial infections (3 cases, 15%), Hypertrophic lichen planus (2, 10%), Hypertrophic DLE plaque (2; 10%), Wart (1, 5%) or fixed cutaneous sporothricosis (1, 5%), zygomycosis (1, 5%). Three cases (15%) were lost in follow up. Cases of chromoblastomycosis were managed with prolonged use of antifungal alone or in combination with saturated solution of potassium iodide and/or debridement. They were followed up for at least six months post treatment.

CONCLUSION

A database comprising diagnostic clues and effective therapeutic intervention have been proposed for these rare subcutaneous mycoses.