Inter-observer reliability of the Onychomycosis Severity Index depending on clinical experience: A review of 50 cases

BACKGROUND

Onychomycosis (ONM) is the most prevalent nail unit pathology, and its severity and monitoring are often based on the visual judgement of clinicians.

OBJECTIVE

The objective of this study is to assess the reliability of the Onychomycosis Severity Index (OSI) classification when utilized by three clinicians with varying levels of clinical experience: an experienced podiatrist (with 5 years of experience), a moderately experienced podiatrist (with 2 years of experience) and an inexperienced podiatrist (a recent graduate familiar with the OSI classification but lacking clinical experience). Additionally, we compared the severity assessments made through visual inspection with those determined using the OSI by different clinicians.

METHODS

We evaluated reliability using the intraclass correlation index (ICC), analysing 50 images of ONM.

RESULTS

The OSI demonstrated a very high level of reliability (ICC: 0.889) across clinicians, irrespective of their experience levels. Conversely, a statistically significant increase in severity was observed when comparing visual assessments with the OSI (p < .001) for ONM severity evaluation.

CONCLUSION

The OSI proves to be a reproducible classification system, regardless of the clinical experience of the practitioner employing it.

Looking Beyond the Hutchinson Sign: A Retrospective Study of Clinical Factors Indicating the Presence and Invasiveness of Nail Unit Melanoma in Patients With Longitudinal Melanonychia

BACKGROUND

The data underlying this article are available in the article.Longitudinal melanonychia (LM) presents a challenge because nail unit melanoma (NUM) must be considered as a differential diagnosis. Because nail matrix biopsy may result in nail dystrophy, it is important to distinguish NUM from LM.

OBJECTIVE

To provide evidence of previously reported clinical factors indicative of NUM in patients with LM.

METHODS

This was a retrospective study of patients who presented with LM and had biopsy-confirmed NUM from 2005 to 2021. Benign LM was either confirmed by biopsy or considered benign if followed without the need for biopsy. Clinical factors associated with LM and NUM were compared by multivariate regression.

RESULTS

A total of 177 patients (97 LM and 80 NUM) were included. Multivariate regression showed that high band color intensity (p = .0031), variegation (p = .0005), nail plate splitting (p = .0017), Hutchinson sign (p = .0027), and band change (p = .001) correlated with malignancy. Nail plate splitting was associated with Breslow thickness.

CONCLUSION

Malignancy should be suspected and biopsy performed in patients with LM and high band color intensity, variegation, nail plate splitting, Hutchinson sign, and band change.

Comparative efficacy of different reconstruction methods after wide local excision of the nail unit: A retrospective study

BACKGROUND

Wide local excision (WLE) of the nail unit is widely used in treating in situ and minimally invasive malignant subungual tumours. After WLE, diverse reconstruction methods have been reported. However, the best repair method has yet to be determined.

OBJECTIVE

To compare the repair effects and postoperative morbidity of secondary intention healing (SIH), artificial dermis grafting combined with secondary intention healing (ADGSIH) and full-thickness skin grafting (FSG) after WLE of the nail unit.

METHODS

We retrospectively reviewed 21 patients who underwent WLE of the nail unit. The re-epithelializing time, functional and cosmetic outcomes, postoperative complications and patients' satisfaction were assessed from the follow-up records.

RESULTS

The FSG group showed more rapid healing and better functional and cosmetic outcomes than the SIH and ADGSIH groups. The ADGSIH and FSG groups showed significant pain relief compared to the SIH group. No serious early and late postoperative complications were reported. The median follow-up period was 26 months, and no recurrence was observed. All patients were satisfied with the treatment.

CONCLUSIONS

FSG after the WLE of the nail unit is a therapeutic option with convenient application, significant pain relief, rapid recovery and satisfying functional and cosmetic outcomes.

Local and Systemic Nail Plate Abnormalities: A Clinical Review

Nail disorders are often difficult to recognize and diagnose because of the subtlety of their presentation and their shared overlapping features that are common to several conditions. Experientially, this is further complicated by the fact that specific training on diagnosis of nail pathologies varies substantially across most residency programs and for a majority of medical and surgical specialties. To distinguish these presentations from true, potentially deleterious nail disorders, clinicians should have familiarity with the most commonly occurring nail pathologies and their associations, and use a systematic approach when examining or evaluating alterations in the nails. In the present study, we review the most common clinical disorders affecting the nail apparatus.

Updates in treatment and impact of nail psoriasis

INTRODUCTION

Nail psoriasis is an inflammatory disorder without a potential scarring outcome, but the nail signs, even the milder ones, can cause discomfort to patients and severely affect their quality of life. Nail psoriasis may be associated with psoriatic arthritis and when it starts during infancy, it may be a predictor of a more severe disease course in adulthood. All these issues contribute to the high economic burden of psoriasis.

AREAS COVERED

Nail psoriasis is notoriously difficult to treat, even though new treatments are in continuous development. This paper provides an update on new treatments and address the current gaps in care of nail psoriasis.

EXPERT OPINION

A better understanding of the disease pathogenesis and more 'real-life' studies will definitely be helpful to improve treatment results. A lower level of heterogeneity should be advisable among trials when evaluating nail psoriasis. Moreover, the relationship between nail psoriasis and psoriatic arthritis should be the focus of unbiased studies in order to better define the real risk that nail psoriasis patients have to develop arthritis.

Systematic study on nail plate assessment: differences in nail plate shape, thickness, power Doppler signal and scanning approach

Ultrasonography (US) of the nail is raising interest in the last years and its feasibility, quickness and amount of descriptive data may provide valuable information. Different authors presented several scanning approaches to nail complex in different pathological conditions, such as psoriasis, but no scanning protocol was ever proposed using healthy subjects as population of reference. The aim of the study was to establish a protocol for the US of nail plate and to assess whether the measurement of the nail plate is influenced by longitudinal vs transverse scan, sex, digit and hand dominance. Using high frequency probe and a Canon Aplio i800 machine, ultrasonographers took scans of nail plates of the hands from healthy subjects. Nail plate shape, thickness and power Doppler signal (PDUS) were evaluated and scans were taken both on longitudinal and transverse axis, at distal, middle and proximal portion of the nail plate or at a fixed angles of - 45°, 0° or + 45°. All the images were then revised and scored using a DICOM software, in order to allow good standards of accuracy and reproducibility. A total of 27 subjects (14 females and 13 males) were assessed. The measures did not result to differ in different portions or angles. Furthermore, no difference appears in sex or dominant vs not dominant hand. A decreasing and significant trend for nail plate thickness was found from the first to the fifth finger. Doppler signal was found in all but one subjects, with a range from almost absent to very evident. No difference was found between groups regarding PDUS. The data provided suggest that a proper scan protocol should include all the nails and evaluation should be done both on longitudinal and transverse axis. Since Doppler signal is highly variable in healthy subjects, its presence should be carefully considered as pathological finding. Observations provided by this study clarify important points of the scanning technique and solve doubts related to which nails should be scanned and where to evaluate quantitative parameters.

Metastases to the nail unit and distal phalanx: a systematic review

Metastases to the nail unit/distal phalanx (NU/DP), although rare, carry a poor prognosis and are frequently misdiagnosed due to variable clinical presentation. Metastases to the NU/DP may be the initial presenting sign of a new or recurrent malignancy. Since the most recent systematic review of case reports (133 patients total) was conducted in 2001, we conducted a systematic review from 1900 to 2021 (244 patients total) to assess any changes in trends in demographics, clinical presentation, and morphology and to report on more updated differential diagnoses. We also examined cases for age, sex, race, ethnicity, Fitzpatrick skin type, laterality, distribution, and diagnostic methods. The PubMed database (1900-2021) was used to detect case-level data per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We found that the most common primary tumors were lung, kidney, and esophagus. A NU/DP metastasis was the presenting sign of malignancy in 31.00% of patients without a former cancer diagnosis. Male to female ratio was 2:1, with average age at diagnosis 58 years. Metastases most often affected a single digit (79.91%), particularly the thumb, followed by the fourth digit. This systematic review corroborates that metastases to the NU/DP may be the initial presenting sign of a new or recurrent malignancy and provides updated diagnostic guidelines. NU/DP metastasis should be considered in both healthy patients and patients with a former malignancy diagnosis presenting with nail changes involving a single digit. Prompt diagnosis and treatment may improve prognosis.

DeepNAPSI multi-reader nail psoriasis prediction using deep learning

Nail psoriasis occurs in about every second psoriasis patient. Both, finger and toe nails can be affected and also severely destroyed. Furthermore, nail psoriasis is associated with a more severe course of the disease and the development of psoriatic arthritis. User independent quantification of nail psoriasis, however, is challenging due to the heterogeneous involvement of matrix and nail bed. For this purpose, the nail psoriasis severity index (NAPSI) has been developed. Experts grade pathological changes of each nail of the patient leading to a maximum score of 80 for all nails of the hands. Application in clinical practice, however, is not feasible due to the time-intensive manual grading process especially if more nails are involved. In this work we aimed to automatically quantify the modified NAPSI (mNAPSI) of patients using neuronal networks retrospectively. First, we performed photographs of the hands of patients with psoriasis, psoriatic arthritis, and rheumatoid arthritis. In a second step, we collected and annotated the mNAPSI scores of 1154 nail photos. Followingly, we extracted each nail automatically using an automatic key-point-detection system. The agreement among the three readers with a Cronbach's alpha of 94% was very high. With the nail images individually available, we trained a transformer-based neural network (BEiT) to predict the mNAPSI score. The network reached a good performance with an area-under-receiver-operator-curve of 88% and an area-under precision-recall-curve (PR-AUC) of 63%. We could compare the results with the human annotations and achieved a very high positive Pearson correlation of 90% by aggregating the predictions of the network on the test set to the patient-level. Lastly, we provided open access to the whole system enabling the use of the mNAPSI in clinical practice.

Preferentially Expressed Nuclear Antigen in Melanoma Expression in Melanocytic Activation (Melanotic Macule) of the Nail Unit. A Potential Diagnostic Pitfall? A Study of 3 Cases

ABSTRACT

Recent studies have argued that melanocyte preferentially expressed nuclear antigen in melanoma (PRAME) is a sensitive and specific immunohistochemical marker of melanoma, including acral melanoma. In addition, loss of p16 expression has recently been suggested to have diagnostic utility in acral melanocytic tumors. The purpose of this study was to report PRAME expression in 3 cases of melanocytic activation (MAN). There were 2 men and 1 woman ranging in age at diagnosis from 46 years to 78 years (mean 61, 6 years). All cases involved a single digit. One lesion was in the fingernail (fifth finger), whereas the remaining 2 lesions were in the toenails (hallux). All the patient presented with a longitudinal melanonychia. The width of the lesions varied from 3 mm (2 cases) to 4 mm (1 case). The duration of the lesions before diagnosis varied from 12 to 24 months. Distinction of MAN from melanoma in situ is not always easy. Some morphological misleading features are illustrated in this study: (1) the suprabasal location of matrix melanocytes with long and thick dendrites within the 2-4 germinative cell layers; (2) the microconfluence of 2 melanocytes and rare melanocytes with a relatively large nucleus, however in a general context of melanocyte scarcity; and (3) the occasional nonspecific nuclear microphtalmia-associated transcription factor (MITF) staining of keratogeneous cells. Such staining could suggest a pagetoid spread of melanocytes in the keratogenous zone. PRAME antibody revealed a strong and diffuse staining in all cases. In addition, all cases were p16 negative. In this study, the melanocyte count inferior to 9 melanocytes/mm and the lack of nuclear atypia or confluence of melanocytes permitted a confident diagnosis of MAN. Limitations of our study lie largely in the small number of cases. Despite this, the expression of PRAME in some MAN seems to hamper its diagnostic value in differentiating benign from malignant lesion.

Hair and Nail Conditions: Nail Conditions

A thorough understanding of nail anatomy can help physicians identify the causes of nail conditions. Observation of changes to the nail can help establish a diagnosis. Patient evaluation should include a physical examination, dermoscopy, and, in some cases, nail biopsy. Onychomycosis is the most common nail condition worldwide, and should be distinguished from other nail conditions with similar manifestations. Empiric onychomycosis treatment without confirmatory tests has been proposed, but studies have shown the cost-effectiveness of testing to prevent inappropriate therapy. Systemic drugs for management include terbinafine and itraconazole. Longitudinal melanonychia is a brown band through the length of the nail. Nail melanoma should be suspected if the band is dark brown-black, is located on a single digit, and occupies 40% or more of the nail plate width. Biopsy with local anesthesia should be performed in patients with suspected nail melanoma or other neoplastic nail conditions. Identification of warning signs of nail melanoma can result in earlier diagnosis and limit potential morbidity and mortality. Nail psoriasis often is overlooked but can affect up to 50% of patients with psoriasis. Nail lichen planus can cause permanent scarring with loss of normal nail anatomy. Other common nail conditions include acute and chronic paronychia, onychocryptosis, onycholysis, Pseudomonas infection (ie, green nails), onychogryphosis, subungual hematoma, and onychomadesis.

Causes of longitudinal nail splitting: a retrospective 56-case series with clinical pathological correlation

BACKGROUND

Split nail (SN) is a rare type of nail fragility syndrome, characterized by a longitudinal fissure involving the entire thickness of the nail plate. Longitudinal nail splitting may be caused by direct injury to the nail plate or matrix insult. Few articles have been published on the topic, most were related to the traumatic aetiology. Some case reports mention tumours and inflammatory disorders as other causes.

OBJECTIVES AND METHODS

The aim of this retrospective study was to analyse the clinical and histopathological features of 56 SN collected at the nail consultation of the dermatology department at Saint Pierre University Hospital in Brussels, between 1997 and 2019.

RESULTS

Fifty-six patients were included (34 women and 22 men) with median age of 44.2 years. The fingernails were 3.2 times more frequently affected than toenails, especially the thumb. The most frequent aetiologies were tumours (45.6%), inflammatory diseases (26.3%) and traumas (19.3%). Congenital (5.3%) and systemic disorders (3.5%) were rarer causes. Histopathological slide review confirmed that alteration of the nail matrix integrity causes split nail, resulting either from matrix stretching by an underlying tumour or from impairment of the keratinization process by inflammatory diseases, melanocytic tumours and Bowen's disease.

CONCLUSIONS

This study is the largest case series of longitudinal nail splitting to date. It is the first to gather nail disorders causing SN with their clinical pathological correlation. The most common causes are traumatisms, tumours and inflammatory disorders. Congenital and systemic disorders are rarer. Tumours are responsible for half of the cases from which one third are malignant, mainly melanoma. When facing a monodactylic SN, benign as well as malignant tumours should be ruled out before concluding to traumatic aetiology.

[Persistently crumbling nails in a patient with limited Dutch proficiency]

BACKGROUND

Nail psoriasis, also called psoriasis unguium, is a variant of psoriasis in which nail changes appear due to inflammation of nail bed or nail matrix. 15% to 50% of patients with cutaneous psoriasis have nail psoriasis, the condition also occurs without or before the appearance of skin lesions.

CASE DESCRIPTION

A 54-year-old male visits his general practitioner because of crumbling of his fingernails. Upon clinical examination, this was interpreted as onychomycosis and treated with oral antimycotics. Due to the lack of improvement and a negative PCR-test on dermatophytes, the condition was later diagnosed as nail psoriasis.

CONCLUSION

Nail psoriasis is often diagnosed as fungal infection of the nails. To make the right diagnosis, a complete medical history should be obtained, and physical examination of skin and joints need to be conducted. Furthermore, we advise to rule out onychomycosis in patients with known skin psoriasis to prevent overtreatment with antimycotics.

Nail matrix scars that result in nail dystrophy resemble cutaneous scars: A new nail trauma model

BACKGROUND

Few studies have described how the injury affects the nail soft tissue under the nail plate. Nail matrix scar is poorly known.

OBJECTIVE

To establish a stable rat nail loss model in a simple way, and to discuss the comparability of this model.

METHODS

A sterile cotton swab dipped in a 10% NaOH solution was used to burn the entire nail matrix and bed plane region, and the specimens were examined on day 3, 7, 14, and 28.

RESULTS

After avulsion of the nail plate, the eponychia and matrix stuck together without any tissue destruction. On day 28, all claws of the experimental group were observed to be permanently damaged, except for one claw malformed regeneration. All impaired nail regeneration had deficiency or functional loss of NMSCs and shared similar characteristics with the cutaneous scars.

CONCLUSIONS

The scar formation of nail matrix was a fundamental reason to nail deficiency of rat or human, providing a research basis for further mechanism or treatment study of nail defect diseases.

Functional Surgery for Subungual Melanoma: Surgical Tips Based on Histological Analysis of 21 Cadavers

BACKGROUND

Amputation has been the standard treatment for subungual melanoma. Although there is growing attention toward a more conservative functional surgery, specific operative techniques are not yet available.

OBJECTIVE

We aimed to provide objective measurements for use in functional surgery by analyzing the anatomy of the nail apparatus obtained from 21 cadavers.

MATERIALS AND METHODS

Nailbed thickness was histologically measured in each subunit, and skin surface anatomy was evaluated to determine the proximal resection margin. Immunohistochemical staining was performed to analyze microvessel distribution according to the nail subunit.

RESULTS

The nailbed thickness was the thinnest at the most proximal point of the nail matrix (thumbs, 1.10 ± 0.42 mm; big toes, 1.15 ± 0.37 mm) and the thickest at the hyponychium (thumbs, 2.86 ± 0.82 mm; big toes, 2.72 ± 0.84 mm). The distance from the eponychium to the skin surface closest to the bony cortex of extensor tendon insertion was 6.92 ± 5.13 mm in thumbs and 5.14 ± 1.59 mm in big toes. The median microvessel density was the highest at the hyponychium (25.74 vessels/mm2) and lowest at the germinal matrix (16.26 vessels/mm2) (p < .05).

CONCLUSION

This histological study offers practical tips, including those to help decide the proximal and deep resection margins, in functional surgery.

Soft Tissue Chondroma: A Possible Diagnosis of Single-Digit Nail Clubbing

Supplemental Digital Content is Available in the Text.

Hutchinson Sign: Biopsy May Assist in Diagnosis of Subungual Melanoma in Situ

BACKGROUND

Early and accurate diagnosis of subungual melanoma (SUM) through histopathologic examination is critical, but lack of clinical suspicion leads to delays in diagnosis. Hutchinson sign (HS) can be one of the important clinical indicators for diagnosing SUM.

OBJECTIVE

To evaluate the diagnostic value of small biopsies of HS for detecting SUM in situ.

METHODS

We retrospectively evaluated 12 patients who were diagnosed as SUM in situ and underwent punch biopsy at HS areas. Clinical features, dermoscopic findings, and histopathologic findings in HS regions were analyzed.

RESULTS

In most cases, HS was seen in hyponychium (11/12, 91.7%) with 1 case found in proximal nail fold, and 1 case in both the hyponychium and proximal nail fold. Dermoscopic features of HS showed irregular diffuse pigmentation (12/12, 100%) and parallel ridge pattern (7/12, 58.3%). Histopathologically, all cases showed irregularly scattered atypical melanocytes with hyperchromatic nuclei. Two cases showed subtle changes in melanocytes with little nuclear atypia, but additional section specimen showed more definitive findings of SUM in situ.

CONCLUSION

We present a supplementary biopsy technique for diagnosing SUM. Biopsy of HS may help in the diagnosis of SUM.

[A boy with an abnormal hallux]

An eleven-year-old boy was seen by the general practioner due to a painfull hallux. The diagnosis unguis incarnatus was made. Therefore, a partial nail extraction was performed. Unfortunately, the patient still had complaints of a painful hallux and was forwarded to the surgical outpatient clinic. We saw a round, hard and benign tumor on the lateral side of the nail (picture 1). We performed a partial nail extraction as well. Due to persistence complaints and the abnormal course and X-ray was performed. On the X-ray an exostosis was seen (picture 2). This confirmed the diagnosis: subungual exostosis. It is a rare clinical manifestation and has a long delay up until diagnosis. It is a benign bone tumor and often seen on the hallux. A radical excision must be performed.

More than just acral melanoma: the controversies of defining the disease

Acral melanoma (AM) is a malignant cutaneous melanocytic tumour specifically located on the palms, soles, and nail apparatus, which are areas of glabrous (hairless) skin. Acral lentiginous melanoma, a subtype of AM, represents a histopathological subtype diagnosis of cutaneous melanoma with unique morphological and structural features. Despite clear definitions, the misuse of these terms and the inconsistency in reporting the histopathological features of AM cases have become a major obstacle to the study of the disease. In this review, we discuss the epidemiology, histopathological features, prognosis, and genetic profile of AM, highlighting the differences observed when histopathological subtypes are considered. The increasing global effort to characterise AM cases from ethnically diverse populations would benefit greatly from a more consistent classification of the disease.

Tumor invasion in the hyponychium is associated with distant metastasis and poor prognosis in subungual melanoma: A histologic landscape of 44 cases

BACKGROUND

Subungual melanoma (SUM) has a poor prognosis because of delayed diagnosis. Its progression, consensus on surgical treatment, and correlation with clinical outcomes remain unclear.

OBJECTIVE

We aimed to identify the pattern of dermal invasion in different locations of the nail apparatus and its relationship with prognosis.

METHODS

In this retrospective review of surgically treated SUM patients between January 2011 and April 2019, the nail apparatus was divided into 5 anatomic subunits: the dorsal roof of proximal nail fold, ventral floor of proximal nail fold, germinal matrix, nail bed, and hyponychium. Invasions in the subunits were categorized using 3 criteria: no tumor, in situ tumor, or invasion.

RESULTS

Among 44 cases of SUM, dermal invasion occurred mostly in the distal areas, with 11, 30, 18, 7, and 4 in the hyponychium, nail bed, germinal matrix, ventral floor of proximal nail fold, and dorsal roof of proximal nail fold, respectively. The patients with hyponychial invasion showed a significantly greater Breslow depth (P = .009), a higher rate of lymph node metastasis (P = .019), distant metastasis (P = .036), and shorter disease-free survival (P = .001).

CONCLUSION

Hyponychial invasion is an important prognostic predictor of SUM, given its strong association with invasion depth, metastatic progression, and disease-free survival. Patients with invasion in the hyponychium should undergo more strict workup, treatment, and surveillance.

Nail Psoriasis Does Not Affect Skin Response to Ixekizumab in Patients With Moderate-To-Severe Psoriasis

Background: Presence of nail psoriasis in patients with plaque psoriasis may be an indicator of greater disease severity. Previously, patients with nail psoriasis have had delayed skin clearance after treatment compared to patients without nail psoriasis. Objective: This post-hoc analysis evaluated the efficacy of ixekizumab in clearance of plaque psoriasis in patients with and without nail psoriasis. Methods: Data were integrated from two phase 3 clinical trials (UNCOVER-2 and UNCOVER-3; N=2570) to assess skin response over 12 weeks of treatment with subcutaneous placebo, etanercept, or ixekizumab in patients with and without nail psoriasis. Nail response was assessed using Nail Psoriasis Severity Index (NAPSI) and skin response was assessed as the percentage of patients achieving 75%, 90%, or 100% improvement in Psoriasis Area and Severity Index (PASI 75, PASI 90, PASI 100) or a score of 0 or 1 on the static Physician Global Assessment (sPGA 0 or 0,1). Results: From baseline to week 12, progressive improvement in psoriasis occurred with ixekizumab and etanercept treatment; however, significantly more patients with nail psoriasis than without mild PASI 75 at weeks 8 and 12 and sPGA (0,1) at week 12 with ixekizumab. Significantly more patients with severe nail psoriasis than mild achieved PASI 75 at weeks 8 and 12 with ixekizumab. Conclusion: Patients with and without nail psoriasis responded well to ixekizumab. The presence of nail psoriasis did not negatively affect skin clearance in patients treated with ixekizumab. ClinicalTrials.gov: NCT01597245, NCT01646177 J Drugs Dermatol. 2020;19(8):741-746. doi:10.36849/JDD.2020.5116.

Unexpected subungual Sarcoptes infestation of toenail - a case report and literature review

Scabies is the skin infestation caused by Sarcoptes scabiei var hominis. It is one of the commonest dermatological infection which can affect people around the world. However, nails are relatively rarely involved, and the fingernails are mostly infected. The report a case of a 77-year-old woman, long-term pensioner of a nursing home, who had isolated toe subungual Sarcoptes infestation. In addition, the results of systematic review of toenails scabies was presented. Analysis of 21 subungual Sarcoptes infestation cases, revealed that patients in any age (median age 45+/-31.7-year-old) and sex can be affected. Most of the patients had concomitant diseases. Seventy-five percent of cases of nail involvement were treated with combined or sequential therapy. The most used drugs were ivermectin (IVR) and permethrin (PER) (each used in 47.6% cases), following γ-BHC (38.1%) and crotamiton (CRO) (23.8%). It seems that the crucial for adequate diagnosis in scabies affected nails is a precise anamnesis, early and accurate diagnosis that consists of examining not only skin lesions, but including assessing toenails, and differentiation of Sarcoptes infestation from other nail diseases as onychomycosis or psoriasis. Important to achieving a cure is at least frequent nail trimming, softening the nail plate with urea or in the difficult cases the mechanical removal of subungual plaque with using of a scabicide in the location allowing to penatrate it under the nail plate.