The transmission of optical radiation through human nails

Novel Henna-Related Naphthazarine Photosensitizers for an Effective Photodynamic Therapy of Onychomycosis

Onychomycosis caused by, e.g., Trichophyton rubrum or Candida albicans is the most common human nail disease with a worldwide prevalence of more than 10%. The therapeutic efficacy of topical antimycotics for the treatment of onychomycosis proved to be inadequate in numerous studies on patients. The main reasons are, above all, the poor bioavailability of the active ingredients in the nail compartment, causing the requirement for extremely long application periods and correspondingly high demands on adherence by the patient. In the present study, we aimed to develop a more effective and prompt photodynamic approach for the treatment of onychomycosis. The principle of photodynamic therapy (PDT) for onychomycosis has already been investigated. However, these studies used photosensitizers such as methylene blue, which were neither optimized for their keratinophilic features nor for their bioavailability in the nail. Hence, we initiated a screening campaign using T. rubrum and C. albicans cell-based assays, infected bovine keratin models, and keratin-penetrating irradiation to identify suitable hit compounds for a PDT approach toward onychomycosis. Here, we report on the discovery of Henna/Lawson-derived keratinophilic naphthazarines that act as highly potent PDT antimycotic photosensitizers with photoresponsiveness when irradiated by light at a keratin-permeable wavelength (>500 nm, e.g., compounds 10 and 11 with PDT-IC50 = 1 and 3 nM, respectively, against T. rubrum), hence with superior efficacy than the positive controls nystatin and clotrimazole. Notably, our photodynamic approach not only affected the actual pathogens but also prevented reinfection of keratin models within 10 days, suggesting an additional efficacy against fungal spores. Compared to established concepts, our proposed PDT approach using the novel naphthazarine photosensitizers could enable an effective, precise, and sustainable therapy option for the future treatment of onychomycosis.

Effect of Nail Thickness on Visible Radiation Transmittance: Implications for New Photodynamic Therapy Technologies in Onychomycosis

Photodynamic therapy is taking importance as a nonintrusive treatment for nail onychomycosis. Knowledge of true transmittance values across nails could lead to qualitative and quantitative improvements in light-based treatments. We have characterized the spectral transmittance of healthy and fungally infected human fingernails and toenails according to nail thickness, and we propose a surface transmittance model for the small-scale optimization of light-based treatments. Transmittance of fingernails and toenails was analyzed by means of spectroradiometric measurements under solar-simulated visible light radiation (400 nm to 750 nm). The nail thickness was measured by means of microscope measurement. Transmittance was highest at longer wavelengths and decreased gradually as the wavelengths became shorter but with a significant nail transmittance of around 20% in the blue region of the spectrum. In the case of nails affected by onychomycosis, transmittance fell to under 10% because of the thickness of the nails, with no changes in spectral characteristics of transmitted light. Nail thickness is the main variable controlling exponentially light transmission in the visible spectrum and not only red radiation is effective for nail onychomycosis PDT. Blue light, the spectral band more effective for PPIX absorption is also effectively transmitted.

Photoonycholysis: new findings

First described in 1961, photoonycholysis (PO) is a rare nail alteration that may result from drug intake, from topical aminolevulinate photodynamic therapy or from photosensitive conditions such as porphyria or pseudoporphyria. Spontaneous PO is rare. This review updates the numerous causes of PO and highlights some new ways producing this condition. Four different types of PO are clearly recognized without relationship with the responsible drug. An updated list of potential inducing drug is provided. Some practical points on PO have been raised. The inability to reproduce photoonycholysis experimentally should be emphasized, and the pathogenesis of PO still needs to be clarified.

The Treatment of Nail Psoriasis: A Review

Nail disease affects most patients with psoriasis and has a substantial medical and psychological impact on the lives of those affected. Frequently, nail psoriasis is associated with severe pain, restriction in daily activity, and emotional agony that require the dermatologist to know the most up-to-date therapies. Unfortunately, no single treatment is paramount, and the choice of therapy must be individualized to disease severity, patient tolerability, cost, and risk of adverse events. Some clinical manifestations include nail pitting, discoloration, onycholysis, subungual hyperkeratosis, and splinter hemorrhages. Currently, no standardized therapeutic regimen exists; and, given the variability in clinical manifestations, multiple modalities may be needed for adequate results. More recently added to the armamentarium of topical and injectable therapies for nail disease are systemic agents, such as biologics, and photochemotherapeutic treatments. These therapies have been used with varying degrees of success. This review highlights the current treatments available for the treatment of nail psoriatic disease.

Case report: photo-onycholysis after PUVA treatment for hypopigmented mycosis fungoides with response to topical steroid

Melanin in the nail bed in patients with skin type VI has been suggested to afford some protection against photo‐onycholysis. We report a case of a 16‐year‐old male patient with skin type VI with onycholysis following PUVA treatment for hypopigmented mycosis fungoides. Symptoms resolved with the application of topical steroid.

Melanoma of the Foot

Melanoma is a rare form of skin cancer that is responsible for most skin cancer deaths globally. Tumors arising on the foot continue to be a particular challenge. Patients present later and lesions are frequently misdiagnosed, leading to more advanced disease with an overall poorer prognosis then melanoma elsewhere. In order to improve early recognition, this article reviews the clinical features of the disease along with published algorithms. Emerging assessment techniques such as dermoscopy are also discussed as tools to improve clinical decision making. Contemporary drug therapies in the treatment of advanced disease are also discussed.

[Recurrence of malignant achromic melanoma of the nail: report of a case]

Le mélanome malin unguéal représente 1,8 à 8,1% des mélanomes malins cutanés. Sa prise en charge s'adresse aujourd'hui aux praticiens de différentes spécialités. L'acte chirurgical initial est une étape incontournable du traitement curatif. La biopsie de la lésion doit être complète, afin de déterminer de façon exacte la profondeur de l'envahissement en cas de malignité. Nous rapportons un cas de mélanome malin achromique à localisation unguéal chez une femme. La chirurgie initiale consistait en une amputation transphalangienne proximale. L’évolution après deux ans était marquée par une récidive avec extension vers le carpe. Ayant subie une reprise chirurgicale avec une exérèse large. Le traitement des récidives est palliatif et vise à apporter un confort de vie au patient. Le principe du traitement fait appel à l'exérèse chirurgicale des lésions. Des alternatives thérapeutiques sont à l’étude.

An in vitro study of the photodynamic effect of rose bengal on Trichophyton rubrum

Onychomycosis, a fungal infection of the finger or toenails, is predominantly caused by Trichophyton rubrum. Treatment is difficult due to high recurrence rates and problems with treatment compliance. For these reasons, alternative therapies are needed. Here we describe the photoactivation of Rose Bengal (RB) using a green laser (λ = 532 nm) at fluences of 68, 133 and 228 J/cm(2) , and assess its fungicidal activity on T. rubrum spore suspensions. A 140 µM RB solution was able to induce a fungicidal effect on T. rubrum when photosensitized with the fluence of 228 J/cm(2) . RB photosensitization using a green laser provides a potential novel treatment for T. rubrum infections.

An investigation into the inhibitory effect of ultraviolet radiation on Trichophyton rubrum

Fungal infection of nails, onychomycosis, is predominantly caused by Trichophyton rubrum. This infection is an important public health concern due to its persistent nature and high recurrence rates. Alternative treatments are urgently required. One such alternative is phototherapy involving the action of photothermal or photochemical processes. The aim of this novel study was to assess which wavelengths within the ultraviolet (UV) spectrum were inhibitory and equally important nail transmissible. Initial irradiations of T. rubrum spore suspensions were carried out using a tunable wavelength lamp system (fluence ≤3.1 J/cm(2)) at wavelengths between 280 and 400 nm (UVC to UVA) to evaluate which wavelengths prevented fungal growth. Light-emitting diodes (LEDs) of defined wavelengths were subsequently chosen with a view to evaluate and potentially implement this technology as a low-cost "in-home" treatment. Our experiments demonstrated that exposure at 280 nm using an LED with a fluence as low as 0.5 J/cm(2) was inhibitory, i.e., no growth following a 2-week incubation (p < 0.05; one-way ANOVA), while exposure to longer wavelengths was not. A key requirement for the use of phototherapy in the treatment of onychomycosis is that it must be nail transmissible. Our results indicate that the treatment with UVC is not feasible given that there is no overlap between the antifungal activity observed at 280 nm and transmission through the nail plate. However, a potential indirect application of this technology could be the decontamination of reservoirs of infection such as the shoes of infected individuals, thus preventing reinfection.

Nail apparatus melanoma: is trauma a coincidence? Is this peculiar tumor a real acral melanoma?

Nail Apparatus Melanoma (NAM) is rare, particularly in Caucasians. Understanding its pathogenesis and collecting epidemiologic data may be difficult due to its location and the exiguity of the case series of this cancer. Cutaneous melanoma has been thought related to UV radiation, and NAM is considered an acral variant of melanoma, even if the nail presents a specific anatomy. Little is reported about pathogenesis, except reports suggesting traumatic injuries as a causal factor. UV exposure is debated in nail melanoma because of its structure. The nail is, in fact, a unique structure with sun-exposed and non exposed melanocytes. NAM arises from the nail melanocytes, located in the nail matrix, which is the germinative part of the nail and composed of a proximal and distal portion. The proximal nail matrix lays under the proximal nail fold that covers it and is non-sun exposed, while the distant nail matrix, clinically visible as the lunula, is sun-exposed, though lying underneath the nail plate. According to these anatomical data, NAM is a distinct melanoma type, and studies need to classify it as acral melanoma or as a particular type of melanoma with its own pathogenesis and prognostic criteria. This study investigates potential risk factors of NAM, emphasizing (i) trauma and (ii) UV exposure among our NAM patients.

Whole genome sequencing of matched primary and metastatic acral melanomas

Next generation sequencing has enabled systematic discovery of mutational spectra in cancer samples. Here, we used whole genome sequencing to characterize somatic mutations and structural variation in a primary acral melanoma and its lymph node metastasis. Our data show that the somatic mutational rates in this acral melanoma sample pair were more comparable to the rates reported in cancer genomes not associated with mutagenic exposure than in the genome of a melanoma cell line or the transcriptome of melanoma short-term cultures. Despite the perception that acral skin is sun-protected, the dominant mutational signature in these samples is compatible with damage due to ultraviolet light exposure. A nonsense mutation in ERCC5 discovered in both the primary and metastatic tumors could also have contributed to the mutational signature through accumulation of unrepaired dipyrimidine lesions. However, evidence of transcription-coupled repair was suggested by the lower mutational rate in the transcribed regions and expressed genes. The primary and the metastasis are highly similar at the level of global gene copy number alterations, loss of heterozygosity and single nucleotide variation (SNV). Furthermore, the majority of the SNVs in the primary tumor were propagated in the metastasis and one nonsynonymous coding SNV and one splice site mutation appeared to arise de novo in the metastatic lesion.

Spatial density of primary malignant melanoma in sun-shielded body sites: A potential guide to melanoma genesis

UV radiation is a major factor in melanoma genesis, but non-UV linked factors are also operational, since primary malignant melanomas can emerge in body sites that never see the sun. The scarcity of melanomas in sun-shielded body sites reflects only the absolute number of melanomas, not the number of tumours per square unit of the surface in which they emerge. Studies on melanoma density conducted by us and others are here briefly reviewed. The access to reliable numbers along with measurable anatomical areas directed our choice of melanomas at the sun-shielded locations described here. Melanomas at the body surface. Calculations of surface areas bearing melanomas relative to the total body surface included sites on the vulva, subungual tissues, volar and palmar skin, and, for comparison melanomas of the face during the same period of time. The density of vulvar melanomas was identical to that in chronically sun-exposed facial skin. Subungual melanomas were almost nine times denser than expected whereas melanomas of palms and soles showed a lower density than expected. Melanomas beneath the body surface. The densities of melanomas in the vagina, anal canal and uvea, were calculated separately and compared to the average density of cutaneous melanomas (CMMs) during the same period of time. Melanomas of the anal canal displayed a density almost twice the average for CMMs, whereas the vaginal melanomas were similar in density to CMMs. In contrast, the density of the uveal melanomas was calculated as 50 and 41 times (men and women, respectively) the average density of CMMs.

CONCLUSION

The high density of some melanomas in sun-shielded body areas indicates the presence of factors underlying the origins of these tumours that seem to be equivalent in strength to UV radiation and also implies that specific anatomical sites favour the emergence and proliferation of melanomas, independent of UV radiation.

Nail biology and nail science

The nail plate is the permanent product of the nail matrix. Its normal appearance and growth depend on the integrity of several components: the surrounding tissues or perionychium and the bony phalanx that are contributing to the nail apparatus or nail unit. The nail is inserted proximally in an invagination practically parallel to the upper surface of the skin and laterally in the lateral nail grooves. This pocket-like invagination has a roof, the proximal nail fold and a floor, the matrix from which the nail is derived. The germinal matrix forms the bulk of the nail plate. The proximal element forms the superficial third of the nail whereas the distal element provides its inferior two-thirds. The ventral surface of the proximal nail fold adheres closely to the nail for a short distance and forms a gradually desquamating tissue, the cuticle, made of the stratum corneum of both the dorsal and the ventral side of the proximal nail fold. The cuticle seals and therefore protects the ungual cul-de-sac. The nail plate is bordered by the proximal nail fold which is continuous with the similarly structured lateral nail fold on each side. The nail bed extends from the lunula to the hyponychium. It presents with parallel longitudinal rete ridges. This area, by contrast to the matrix has a firm attachment to the nail plate and nail avulsion produces a denudation of the nail bed. Colourless, but translucent, the highly vascular connective tissue containing glomus organs transmits a pink colour through the nail. Among its multiple functions, the nail provides counterpressure to the pulp that is essential to the tactile sensation involving the fingers and to the prevention of the hypertrophy of the distal wall tissue, produced after nail loss of the great toe nail.

Photo-onycholysis caused by olanzapine and aripiprazole

Photo-onycholysis associated with drugs is an uncommon disorder. We report the case of a woman who developed photo-onycholysis on multiple nails after uptake of olanzapine. Substitution of olanzapine with aripiprazole further exacerbated the problem. The possible mechanisms of photo-onycholysis development by modern atypical antipsychotics, modulating dopamine receptors, are discussed.

Acral lentiginous melanoma: a clinicoprognostic study of 126 cases

BACKGROUND

Although the histopathological subtype of melanoma has not been clearly proven to carry independent prognostic significance, acral lentiginous melanoma (ALM) seems to confer a poorer prognosis mainly because disease is often more advanced at the time of diagnosis.

OBJECTIVES

To investigate the distinctive epidemiological and clinical characteristics of ALM, a peculiar histological entity, and to identify prognostic factors.

METHODS

We performed a register-based review of cases from a single large referral centre, the University Hospital Department of Dermatology, Lyons, France. We reviewed patient demographics, the initial presentation of the lesion, and clinical outcome. ALM-specific and disease-free survival were estimated using the KaplanMeier method and compared using the log-rank test. A Cox model was used to identify prognostic factors.

RESULTS

One hundred and twenty-six patients were identified as having histopathology-proven ALM in our melanoma patient register from 1996 to 2004. There were 46 (37%) subungual ALM and 80 (63%) ALM on soles, palms and nonvolar sites. The mean age at diagnosis was 63 years. There were 44 (35%) men and 82 (65%) women, sex ratio M/F 1 : 1.86. The mean Breslow thickness was 2.51 mm (range: in situ to 20 mm). There was no evidence of overexposure to ultraviolet radiation, nor was there found a predisposing genetic trait. Only 16 (13%) patients recalled a history of trauma. Thirty-four ALM (28%) were unpigmented. The median ALM-specific and disease-free survival were 13.5 and 10.1 years, respectively. The 5-year survival rate was 76%. Multivariate analysis identified tumour thickness, male gender and amelanosis as independent clinical prognostic factors for both ALM-specific and disease-free survival.

CONCLUSIONS

Our study provides specific information on the clinical characteristics and outcome of this uncommon histological subtype of melanoma. However, the pathogenesis remains unknown. Breslow thickness, male gender and amelanosis were significantly associated with a poorer prognosis.

Subungual Bowen's disease treated by topical aminolevulinic acid—photodynamic therapy

A 66-year-old man presented with an 18-month history of progressive nail dystrophy involving his left index finger. A diagnostic biopsy specimen confirmed the clinical suggestion of subungual Bowen's disease (carcinoma in situ). Various treatment options were considered, and the decision was made to treat with photodynamic therapy using topical 5-aminolevulunic acid administered as two treatments 4 weeks apart. The patient was reviewed 3 months after treatment and then regularly at 6-month intervals. Thirty months after treatment there remained no clinical evidence of recurrence of the condition with preservation of a normal nail unit. Although the successful treatment of cutaneous Bowen's disease with photodynamic therapy is well documented, this is the first report of the successful treatment of subungual Bowen's disease using topical aminolevulunic acid-photodynamic therapy.

Shared phenotypes among segmental progeroid syndromes suggest underlying pathways of aging

Segmental progeroid syndromes are those whose phenotypes resemble accelerated aging. Here we analyze those phenotypes and hypothesize that short telomeres produce the same group of symptoms in a variety of otherwise unrelated progeroid syndromes. Specific findings are the following: (a) short telomeres in some progeroid syndromes cause an alopecia/osteoporosis/fingernail-atrophy group of symptoms; (b) fingernail atrophy in progeroid syndromes resembles the natural slowing of nail growth that occurs in normal aging and nail growth velocity, and may be a marker of replicative aging in keratinocyte stem cells; (c) alopecia and reduced hair diameter parallel the nail results; (d) osteoporosis in Dyskeratosis Congenita resembles age-related osteoporosis, but the same is not true of other progerias; and (e) gray hair is associated with short telomeres, but may also involve reactive oxygen species. On the basis of these results, we make several predictions and discuss how the segmental quality of progeroid syndromes may provide insight into normative aging.

Bowen's disease of the nail bed

A 77-year-old man presented with a 2-year history of left thumbnail dystrophy, purulent discharge and aching pain. There was no history of trauma. On examination there was a linear area of nail dystrophy and dyschromia of the nail bed. The nail plate was thinned proximally. No other digits were affected. There was no lymphadenopathy. X-ray of the digit was normal. Longitudinal nail biopsy revealed Bowen's disease along the length of the nail bed and nail matrix specimen. After avulsion of the nail plate, the nail matrix and tumour were fully excised. The defect was repaired with a split-skin graft. His symptoms were relieved.

Nail apparatus melanoma

Nail apparatus melanoma is a relatively rare variant of melanoma with a disproportionately high mortality when compared with melanoma elsewhere. The aetiology and natural history remain poorly understood. There is no clear epidemiological association with race, skin type or sun exposure. Universally accepted clinical and histological criteria for the diagnosis of early nail apparatus melanoma have not been defined. The two cardinal clinical signs are melanonychia striata and Hutchinson's sign. These are useful but not pathognomonic of melanoma. Diagnostic delay is frequent and patients commonly have advanced disease at the time of diagnosis. Surgical excision is advocated for treatment of stage I disease; however, the most appropriate re-excision margins, including the level of amputation where required, have not been determined. Early diagnosis and excision of the tumour is the only treatment known to increase survival. Adjuvant systemic chemotherapy, isolated limb perfusion, and routine elective lymph node dissection have been used, but no survival benefit has been demonstrated.

Nail melanoma: a review of the literature with recommendations to improve patient management

In this review, the current state of knowledge concerning nail melanoma is summarized. The pathogenesis, histological findings, clinical presentation, treatment and prognosis of this rare form of cutaneous melanoma are discussed. Important clinical clues to the early diagnosis of nail melanoma are highlighted and recommendations to improve the management of patients are suggested.

Mohs micrographic surgery of the nail unit

Malignancies of the nail unit are relatively uncommon, with squamous cell carcinoma (SCC) representing most of the reported cases. Squamous cell carcinoma of the nail unit, although commonly considered to be a curable malignancy, can and does kill. Review of the literature as well as a personal series confirm that Mohs micrographic surgery is an ideal treatment for periungual and subungual SCCs without osseous involvement. In addition, the anatomy and histology of nail unit SCC, as well as prognostic factors and perioperative evaluation as they relate to performing Mohs micrographic surgery, are reviewed.

Measurement technique for the determination of blood oxygen saturation

A new optical measurement technique based on spectral scanning is described for the determination of oxygen saturation of whole blood. The principles of this technique are outlined, together with a calibration procedure used to test its feasibility in vitro. The preliminary results show that the accuracy of the new technique is of the order +/- 2% over the full range of oxygen saturation. This degree of accuracy is comparable with commercial CO-oximeters.

Onycholysis in a case of atopic eczema treated with PUVA photochemotherapy

Onycholysis following the ingestion of psoralens and subsequent exposure to natural sunlight has been reported on several occasions and was first reported following photochemotherapy in 1978 by Ortonne and Baran from France and in 1979 by Mackie from Scotland. Mackie commented that she hoped to stimulate further reports of onycholysis induced by PUVA photochemotherapy in order to establish whether or not it was a definite complication of such treatment. Since then, there has been a dearth of similar reports. We describe a patient with severe atopic eczema and alopecia totalis who developed onycholysis of all finger nails and a toe nail during PUVA photochemotherapy.

Drug-induced photo-onycholysis. Three subtypes identified in a study of 15 cases

We have studied 15 patients with photo-onycholysis induced by tetracyclines, psoralens, or fluoroquinolones. Three distinct clinical subtypes of onycholysis were seen. Type I showed a half-moon-shaped separation that was concave distally. Type II had a circular notch opened distally and shaped as if the distal nail plate had acted as a convex lens. In type III the changes were located in the central part of the nail bed with no connection to the margins. Ultraviolet (UV) irradiation of normal fingernails with various wavelengths showed that 3% to 20% of the irradiation could penetrate the nail. The different patterns of photodamage might be caused by the nail acting as a lens. Less protection by lack of melanin and absence of sebum and stratum granulosum may favor penetration of UV irradiation and explain why the skin was not always affected.

Polydactylous Bowen's disease of the nail

We present three patients with Bowen's disease of the fingernail folds and beds in which there was polydactylous involvement and add those to five similarly afflicted patients described by other authors. Bowen's disease of the nail is a distinctive type of squamous cell carcinoma that differs from other variants. It is potentially an autochthonous process that can involve more than one nail with the passage of time. Seven-eighths of the patients described in this series were men. A majority had involvement of both hands. No metastases were seen.

Spontaneous photo-onycholysis

Three cases of onycholysis following, and apparently caused by, sun exposure are reported. No case was associated with drug ingestion or demonstrable metabolic abnormality. Cutaneous phototesting of all patients with an irradiation monochromator was within normal limits, although the action spectrum for the defect may lie in the ultraviolet-A (UV-A) region. This appears to be the first report of spontaneous photo-onycholysis.