New Tools in Nail Disorders

Dermatophytic melanonychia: A case series of an increasing disease

BACKGROUND

Melanonychia refers to brown-black colour pigmentation due to melanin or not-melanin deposition in the nail plate. Onychoscopy allows to distinguish if the pigmentation is due by melanin or not. The main causes of non-melanic pigmentation are subungual haematoma and pigmented onychomycosis. Fungal melanonychia (FM) is rare and may present as diffuse or longitudinal pigmentation. Differential diagnosis includes melanic activation, such as ethnic-type nail pigmentation or frictional melanonychia, but also versus melanic proliferation, such as nevus or nail melanoma. Fungal melanonychia can be due to a colonisation by fungi with black variant or by melanin activation due to inflammation of fungal invasion.

OBJECTIVES

The aim of paper is to increase clinical and dermoscopic knowledge of this increasingly frequent disease.

METHODS

In this retrospective observational study, twenty patients with dermatophytic melanonychia were collected, with available clinical and dermoscopic pictures. The diagnosis of dermatophytic melanonychia was made based on clinical manifestation and mycological examination. KOH smear was performed in all cases. For each patient, clinical data included: age, gender, type of melanonychia and involved fingers.

RESULTS

This study aimed to show increased incidence of dermatophytic melanonychia and its correct management. In addition, we reviewed our collected cases and described the clinical and dermoscopic features of dermatophytic melanonychia.

CONCLUSIONS

The results of this study showed that physicians should keep in mind the diagnosis of this increasing disease, and that it cannot be performed relying only on clinical grounds. We would like to highlight the importance of tools as KOH examination, culture and dermoscopy.

Onychoscopy: an observational study in 237 patients from the Kashmir Valley of North India

Background

Nail disorders comprise approximately 10% of all dermatological conditions. Because diagnosis is not always possible by clinical means alone, additional diagnostic procedures may be required at times. Dermoscopy of nails (onychoscopy) has shown promising results in diagnosing various nail disorders and also avoids time-consuming investigations such as culture and biopsy.

Objective

To study the dermoscopic features of various nail disorders to determine the correlation between KOH examination and onychoscopic patterns in patients with the clinical suspicion of onychomycosis, and to differentiate benign pigmented lesions from malignant ones.

Methods

An open, observational and cross-sectional study of 237 patients was conducted. All patients underwent clinical examination and the affected nails were examined with a dermatoscope. The onychoscopic patterns were identified and recorded.

Results

The study included 237 patients with the following diagnoses: 81 onychomycosis, 63 psoriasis, 27 lichen planus, 30 longitudinal melanonychia, 24 connective tissue disorders, 5 onychophagia and nail tics, 3 subungual verrucae, 2 glomus tumor, 1 Darier disease, and 1 enchondroma. The most common onychoscopic findings were spiked pattern in cases of onychomycosis, dilated and tortuous capillaries in cases of psoriasis, longitudinal streaks and nail fragmentation in cases of lichen planus, and enlarged capillaries in cases of connective tissue diseases.

Limitations

The study was only observational and did not compare the results to biopsy and culture.

Conclusions

Onychoscopy may be used as an important diagnostic tool when evaluating nail disorders. It should be used to aid in the diagnosis of various nail disorders and to avoid unnecessary and time-consuming investigations.

Onychoscopy: an observational study in 237 patients from the Kashmir Valley of North India

Background: Nail disorders comprise approximately 10% of all dermatological conditions. Because diagnosis is not always possible by clinical means alone, additional diagnostic procedures may be required at times. Dermoscopy of nails (onychoscopy) has shown promising results in diagnosing various nail disorders and also avoids time-consuming investigations such as culture and biopsy. Objective: To study the dermoscopic features of various nail disorders to determine the correlation between KOH examination and onychoscopic patterns in patients with the clinical suspicion of onychomycosis, and to differentiate benign pigmented lesions from malignant ones. Methods: An open, observational and cross-sectional study of 237 patients was conducted. All patients underwent clinical examination and the affected nails were examined with a dermatoscope. The onychoscopic patterns were identified and recorded. Results: The study included 237 patients with the following diagnoses: 81 onychomycosis, 63 psoriasis, 27 lichen planus, 30 longitudinal melanonychia, 24 connective tissue disorders, 5 onychophagia and nail tics, 3 subungual verrucae, 2 glomus tumor, 1 Darier disease, and 1 enchondroma. The most common onychoscopic findings were spiked pattern in cases of onychomycosis, dilated and tortuous capillaries in cases of psoriasis, longitudinal streaks and nail fragmentation in cases of lichen planus, and enlarged capillaries in cases of connective tissue diseases. Limitations: The study was only observational and did not compare the results to biopsy and culture. Conclusions: Onychoscopy may be used as an important diagnostic tool when evaluating nail disorders.

Examen mycologique en dermatologie

Dermatomycoses are dermatological infections very commonly encountered in private dermatological practice since they affect up to one third of the population. However, the symptoms are very often shared by other skin infections and disorders and may be highly atypical. It is thus impossible to make a diagnosis with any certainty on clinical grounds alone. For this reason, mycological diagnosis is essential to either confirm or rule out dermatomycosis, and is unavoidable when antifungal therapy is required for the treatment of ringworm of the scalp or beard, or for onychomycosis. It is also vital where therapy guided by the clinical appearance of lesions has failed or in the event of recurring skin lesions. Confirmation of mycosis enables antifungals to be initiated and a negative test warrants investigation for other underlying causes for the lesions seen. However, regardless of the mycological diagnostic technique employed, the quality of the results depends chiefly on the quality of sampling of the infected site, but also on the expertise of the microbiologist. Standard mycological testing remains the most informative, the least expensive and the sole examination capable of isolating the causative fungus irrespective of the type of mycosis, such as dermatophytosis, scytalidiosis, mould-induced ungual infection, candidiasis, or infections due to Malassezia sp. This is the only examination able to identify epidemiological variations. All other more recent techniques are either based upon simple demonstration of the fungal elements involved, without identification of the fungal species in question, or else they are reliant upon a fungal database that is generally highly incomplete.

Dermoscopic patterns in patients with a clinical diagnosis of onychomycosis-results of a prospective study including data of potassium hydroxide (KOH) and culture examination

Background:

Onychomycosis is the most common nail disease, representing 50% of cases affecting the nail apparatus. The diagnosis is made by clinical examination along with the KOH exam of the nail and culture of the sample. However, not all dermatologists have access to a mycology lab.

Objective:

To determine the correlation between KOH examination and dermoscopic patterns in patients with clinical diagnosis of onychomycosis.

Patients/Methods:

A descriptive, open, observational, prospective, cross-sectional study of 178 patients with clinical suspicion of onychomycosis was conducted. All patients underwent clinical examination, dermoscopy with a DermLite PHOTO dermatoscope (3Gen, San Juan Capistrano, CA, USA), KOH assessment and culture analysis. The most frequent dermoscopic patterns were identified and their correlation with the clinical subtype of onychomycosis was analyzed.

Results:

The study included 178 patients with clinical suspicion of onychomycosis. Of these, 155 (87.1%) had positive direct KOH examination for onychomycosis. Eighty-seven patients (56.13%) presented with clinical onychomycosis pattern of total dystrophic onychomycosis (TDO), 67 (43.23%) with distal lateral subungual onychomycosis (DLSO), 1 (0.65%) with trachyonychia). Dermoscopic patterns of onychomycosis showed the following frequencies: the spiked pattern was present in 22 patients (14.19%), longitudinal striae pattern in 51 patients (32.9%) and linear edge pattern in 21 patients (13.55%). We identified a pattern described as “distal irregular termination” in 41 patients with TDO and 26 with DLSO.

Conclusions:

This is the fist study conducted in a Mexican population that uses dermoscopy as a diagnostic tool along with the KOH examination for the diagnosis of onychomycosis. Dermoscopy may be used as an important diagnostic tool when evaluating nail disease. However, it should not be used as the only diagnostic criteria for onychomycosis.

Tangential excision of pigmented nail matrix lesions responsible for longitudinal melanonychia: evaluation of the technique on a series of 30 patients

OBJECTIVES

We sought to assess the shave biopsy technique, which is a new surgical procedure for complete removal of longitudinal melanonychia. We evaluated the quality of the specimen submitted for pathological examination, assessed the postoperative outcome, and ascertained its indication between the other types of matrix biopsies.

DESIGN

This was a retrospective study performed at the dermatologic departments of the Universities of Liège and Brussels, Belgium, of 30 patients with longitudinal or total melanonychia.

RESULTS

Pathological diagnosis was made in all cases; 23 patients were followed up during a period of 6 to 40 months. Seventeen patients had no postoperative nail plate dystrophy (74%) but 16 patients had recurrence of pigmentation (70%).

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

Shave biopsy is an effective technique for dealing with nail matrix lesions that cause longitudinal melanonychia over 4 mm wide. Recurrence of pigmentation is the main drawback of the procedure.

Confocal laser scanning microscopy as a new valuable tool in the diagnosis of onychomycosis - comparison of six diagnostic methods

Onychomycosis is common and can mimic several different nail disorders. Accurate diagnosis is essential to choose the optimum antifungal therapy. The aim of this study was to evaluate the use of confocal laser scanning microscopy (CLSM) and optical coherence tomography (OCT) as new non-invasive diagnostic tools in onychomycosis and to compare them with the established techniques. In a prospective trial, 50 patients with suspected onychomycosis and 10 controls were examined by CLSM and OCT. Parallel KOH preparation, culture, PAS-staining and PCR were performed. PCR showed the highest sensitivity, followed by CLSM, PAS and KOH preparation. OCT offered the second best sensitivity but displayed the lowest specificity. CLSM and KOH preparation showed a high specificity and CLSM offered the best positive predictive value, similar to KOH preparation and OCT. Fungal culture showed the lowest sensitivity and the worst negative predictive value, yet culture and PCR are the only techniques able to identify genus and species. In summary, CLSM was comparable to PAS staining and superior to KOH preparation. Due to the low specificity we assess OCT not as appropriate. In the differentiation of species PCR outplays the fungal culture in terms of time and sensitivity.

Nail digital dermoscopy (onychoscopy) in the diagnosis of onychomycosis

BACKGROUND

Distal subungual onychomycosis and traumatic onycholysis are the most common causes of toenail abnormalities, and differential diagnosis is often impossible without mycology.

OBJECTIVES

To identify and describe dermoscopic signs specific for distal subungual onychomycosis that could facilitate its diagnosis and differentiation from traumatic mycologically negative onycholysis and to determine the sensitivity and specificity of these dermoscopic features.

METHODS

We performed a retrospective study at the Outpatient Consultation for Nail Diseases of the Department of Dermatology of the University of Bologna. Dermoscopic digital images of 57 consecutive patients who underwent global photography, videodermoscopy and mycological examination for onycholysis of a single toenail between 1 December, 2010 and 30 June, 2011, were evaluated and compared. Digital dermoscopic images of onycholysis of the great toenail were evaluated for the presence of peculiar dermoscopic features. The presumptive dermoscopic diagnosis was compared with results of mycology.

RESULTS

Evaluation of videodermoscopic images allowed us to identify three recurring peculiar dermoscopic features, two of which were present only in distal subungual onychomycosis (jagged proximal edge with spikes of the onycholytic area and longitudinal striae) and one only in traumatic onycholysis (linear edge - without spikes - of the onycholytic area).

CONCLUSIONS

We found distinctive dermoscopic signs that are exclusive to distal subungual onychomycosis and to traumatic onycholysis. Detection of these signs is simple and can, in selected cases, help to avoid mycology.

Presentation, microsurgical therapy, and clinical outcomes in three cases of expanding melanonychia of the nail unit in children

The management of expanding melanonychia in childhood is controversial. Here, we present three cases and discuss their operating indications and reconstruction. Between January 1, 1995 and December 31, 2007, one boy and two girls, were operated for expanding melanonychia, involving the thumb, index finger or the middle finger. They were 2, 4, and 7 years at the time of surgery. A complete resection of the nail plate was performed followed by a direct finger reconstruction using a free short-pedicle vascularized nail flap of the toe. Histology showed a junctional nevus in all cases. The follow-ups were after 2, 3, and 5 years and without any complications or recurrence. Regarding reconstruction, the mean Foucher and Leclère score were, respectively, 17 and 16 points. It is concluded that for expanding melanonychia, in case of doubt, an examination of the entire lesion is necessary. Reconstruction of the nail unit after wide excision with nail plate ablation can be performed using microsurgery as discussed below. However, new guidelines on shave biopsy can make this microsurgical procedure obsolete.