Diagnostic Applications of Nail Clippings

Alopecia Areata of the Nails: Diagnosis and Management

Background: Alopecia areata (AA) is a common form of non-scarring alopecia characterized by acute hair loss. Nail involvement, though not always present, can occur in AA patients. Nail changes are more frequent in severe forms of AA and in children. Methods: Literature related to nail changes in AA was comprehensively reviewed after a search on the PubMed database without time restrictions in order to identify common clinical presentations and associated factors to aid clinicians with the correct evaluation and management of these dystrophies. Results: Nail changes in AA include pitting, trachyonychia, leukonychia, red lunula, and miscellaneous alterations such as longitudinal ridging and brittle nails. Nail changes are usually asymptomatic but, nevertheless, sometimes cosmetically disfiguring and can be associated with a reduced quality of life and impaired daily activities. Conclusions: Nail changes in AA may precede or follow hair loss and can occur as an isolated finding. Diagnosis may require a biopsy for definitive identification. Spontaneous improvement is possible, particularly in children, and treatment is not always necessary. Further research is, however, needed to establish a consensus on treatment approaches according to age and severity.

CO2 Laser-Assisted Nail Sampling for Mycological Testing in Onychomycosis

Introduction

Onychomycosis is the most common nail infection, predominantly caused by Trichophyton spp., and is divided into four main types. Confirmatory testing is crucial, but obtaining an adequate sample may be challenging. We suggest the use of carbon dioxide (CO2) laser for painlessly detaching the nail plate during mycological examination and ensuring a sufficient specimen.

Methods

We retrospectively enrolled 25 patients with distolateral onychomycosis, treated according to the following protocol: (1) multiple passes of CO2 laser at 10 W in continuous mode along the proximal border of the affected nail plate; (2) the nail plate was gently cut; (3) the nail bed was curetted; (4) subungual debris and plate fragments were collected for KOH test and culture.

Results

The mean visual analog score (VAS) for pain experienced during the procedure was 0.7 (SD: 2.1), indicating that the sampling was relatively painless for the majority of patients. There were no permanent changes observed in the nail unit of any patients during the follow-up visits as a result of using the CO2 laser.

Conclusion

We firmly believe that the use of lasers offers numerous advantages, including ease of use, reduced pain perception, and the ability to target the proximal margin of fungal infections where viable hyphae are significantly represented.

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Basic Concepts in Nail Pathology

ABSTRACT

Understanding nail pathology is complex for general pathologists and even for those dermatopathologists who do not receive many nail samples in their laboratories. In this article, we attempt to review some of the primary entities in nail pathology with the aid of modern interpretations of nail histology and embryology. We also provide diagrams that can aid in comprehending this field of pathology.

Update on nail unit histopathology

Histopathologic evaluation of the nail unit is an essential component in the diagnosis of nail unit disorders. This review highlights recent updates in nail unit histopathology and discusses literature covering a wide range of nail disorders including melanoma/melanocytic lesions, squamous cell carcinoma, onychomatricoma, onychopapilloma, onychomycosis, lichen planus, and other inflammatory conditions. Herein we also discuss recent literature on nail clipping histopathology, a useful and noninvasive diagnostic tool that continues to grow in popularity and importance to both dermatologists and dermatopathologists.

Onychomycosis: Old and New

Onychomycosis is a common chronic fungal infection of the nail that causes discoloration and/or thickening of the nail plate. Oral agents are generally preferred, except in the case of mild toenail infection limited to the distal nail plate. Terbinafine and itraconazole are the only approved oral therapies, and fluconazole is commonly utilized off-label. Cure rates with these therapies are limited, and resistance to terbinafine is starting to develop worldwide. In this review, we aim to review current oral treatment options for onychomycosis, as well as novel oral drugs that may have promising results in the treatment of onychomycosis.

Adult and Pediatric Nail Unit Melanoma: Epidemiology, Diagnosis, and Treatment

Nail unit melanoma (NUM) is an uncommon form of melanoma and is often diagnosed at later stages. Approximately two-thirds of NUMs are present clinically as longitudinal melanonychia, but longitudinal melanonychia has a broad differential diagnosis. Clinical examination and dermoscopy are valuable for identifying nail findings concerning malignancy, but a biopsy with histopathology is necessary to confirm a diagnosis of NUM. Surgical treatment options for NUM include en bloc excision, digit amputation, and Mohs micrographic surgery. Newer treatments for advanced NUM include targeted and immune systemic therapies. NUM in pediatric patients is extremely rare and diagnosis is challenging since both qualitative and quantitative parameters have only been studied in adults. There is currently no consensus on management in children; for less concerning melanonychia, some physicians recommend close follow-up. However, some dermatologists argue that the "wait and see" approach can cause delayed diagnosis. This article serves to enhance the familiarity of NUM by highlighting its etiology, clinical presentations, diagnosis, and treatment options in both adults and children.

A call for nail clipping histopathology to become an essential component of the routine evaluation of melanonychia: Benefitting patients as a triage and surgical planning maneuver

We call on dermatologists and dermatopathologists to include nail clipping histopathology as an essential component of the routine evaluation of melanonychia. This manuscript demonstrates a case where an adult woman with broad melanonychia of the right thumbnail declined a nail matrix biopsy, but was amenable to a nail clipping.The nail clipping showed pigmentation, melanocyte remnants, and small cavities in the nail plate. These features have been published previously by our group as a clue to nail unit melanoma within nail clippings.This patient was rapidly triaged for nail matrix biopsy, which demonstrated nail unit melanoma in situ. Every patient with melanonychia can benefit from a nail clipping by examination of the location of the pigmentation within the nail plate for surgical planning, and if melanocyte remnants are detected, the nail clipping also serves as a rapid triage mechanism for nail matrix biopsy to evaluate for nail unit melanoma. Fontana-stained sections will highlight the pigmentation in the nail plate, and its location in the nail plate can easily be described by the dermatopathologist. Nail clippings performed in the setting of clinically apparent melanonychia may show helpful histopathologic findings of pigmented fungi, hemorrhage, external pigmentation, features of other pigmented nail unit tumors, as well as other entities. Nail clipping histopathology can provide extensive information in the evaluation of melanonychia with minimal discomfort for a patient, and little disruption to a physician's clinic flow. With this additional case of a nail unit melanoma diagnosed after initial concern found in a nail clipping, as well as other information in the literature, it is clear that melanocyte remnants found in nail clippings are reliable concerning features related to nail unit melanoma in adults. With knowledge of these histopathologic features in nail clippings and the significance of melanocyte remnants, the dermatopathologist can play a crucial role in the use of a nail clipping as a life-saving diagnostic maneuver. Accordingly, given the potential benefit to patients in this setting, as well as other uses of a nail clipping in the evaluation of melanonychia, we call on dermatologists and dermatopathologists to innovate the routine evaluation of melanonychia through the routine employment of nail clippings for histopathologic evaluation.

Deferring Nail Mycological Sampling during the COVID-19 Pandemic: Recommendations from a Multidisciplinary Panel of Nail Specialists

Onychomycosis is the most common nail condition seen in clinical practice, with significant impact on quality of life. Clinical examination alone is insufficient for accurate diagnosis, but mycological confirmation can be challenging during the COVID-19 pandemic. In this letter, a multidisciplinary panel of dermatologists, a podiatrist, dermatopathologists, and a mycologist, discuss considerations for mycological sampling during the pandemic.

Diagnosis of Onychomycosis: From Conventional Techniques and Dermoscopy to Artificial Intelligence

Onychomycosis is a common fungal nail infection. Accurate diagnosis is critical as onychomycosis is transmissible between humans and impacts patients' quality of life. Combining clinical examination with mycological testing ensures accurate diagnosis. Conventional diagnostic techniques, including potassium hydroxide testing, fungal culture and histopathology of nail clippings, detect fungal species within nails. New diagnostic tools have been developed recently which either improve detection of onychomycosis clinically, including dermoscopy, reflectance confocal microscopy and artificial intelligence, or mycologically, such as molecular assays. Dermoscopy is cost-effective and non-invasive, allowing clinicians to discern microscopic features of onychomycosis and fungal melanonychia. Reflectance confocal microscopy enables clinicians to observe bright filamentous septate hyphae at near histologic resolution by the bedside. Artificial intelligence may prompt patients to seek further assessment for nails that are suspicious for onychomycosis. This review evaluates the current landscape of diagnostic techniques for onychomycosis.

Prevalence of Onychomycosis among Patients with Transverse Overcurvature of the Nail: Results of a Cross-Sectional Study

Introduction

Transverse overcurvature of the nail (TON) represents one of the main reasons for dermatological consultations due to nail conditions. Association between TON and subungual hyperkeratosis is common and simulates onychomycosis, constituting a difficult differential diagnosis by clinical features. Many cases are treated in daily practice with antifungal therapy even without mycological confirmation. The aim of this study was to determine the prevalence of onychomycosis among patients with TON associated with subungual hyperkeratosis.

Methods

All subjects with clinical diagnosis of TON and subungual hyperkeratosis were subjected to a thorough clinical history, detailed clinical examination, digital photography, and collection of nail clipping and subungual debris for histopathological and microbiological examination (direct microscopy).

Results

Sixty-five samples were collected from 62 female (95.4%) and 3 male (4.6%) participants. Age range was between 34 and 83 years (mean age, 61.2 years). Twenty-eight samples were positive for onychomycosis, giving a 43.07% prevalence rate of onychomycosis among TON associated with hyperkeratosis.

Discussion/Conclusion

According to our data, the prevalence of onychomycosis in patients with TON associated with subungual hyperkeratosis was 43.07%, confirming the need to rule out fungal infection in TON associated with subungual hyperkeratosis prior to considering any unnecessary antifungal treatment.

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.

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.

Trachyonychia: Review and Update on Clinical Aspects, Histology, and Therapy

Trachyonychia is a disorder of the nail unit that most commonly presents with rough, longitudinally ridged nails (opaque trachyonychia) or less frequently, uniform, opalescent nails with pits (shiny trachyonychia). The term trachyonychia refers to 'rough nails.' This article comprehensively reviews the clinical, histologic, and therapeutic aspects of trachyonychia. The authors' preferred evaluation and management strategies of trachyonychia are included.

Sex-related chemical differences in keratin from fingernail plates: a solid-state carbon-13 NMR study

The carbon-13 solid-state NMR reveals chemical differences in fingernail keratin between young, healthy males and females.

Acral manifestations of fungal infections

Fungal infections, which are named according to the body site involved, can affect any skin area, the fingernails, or the toenails. Numerous fungal agents are responsible for both superficial and deep fungal diseases. Dermatophytes and Candida spp are the most common causative organisms on the surface of the hands, feet, and nails of patients with superficial fungal diseases; however, although deep fungal infections of the skin are less common compared with superficial fungal diseases, their incidence is increasing worldwide due to cross-border travel. Most superficial fungal diseases are diagnosed clinically, but sometimes direct microscopic examination with potassium hydroxide and fungal culture may be necessary for diagnosis, especially in patients suspected of having tinea incognito. In cases of superficial fungal infections except for onychomycosis and tinea incognito, topical treatments are usually sufficient and effective, but systemic treatments may be required in recalcitrant cases. Deep fungal diseases may resemble each other clinically; therefore, the organism must be identified with laboratory methods and should be treated for a long period. We review the most important clinical, diagnostic, and therapeutic aspects of fungal diseases. This paper covers fungal problems encountered both in hospitals and in general practice.