Classification of non-tumorous skin pigmentation disorders using voting based probabilistic linear discriminant analysis.

Non-tumorous skin pigmentation disorders can have a huge negative emotional impact on patients. The correct diagnosis of these disorders is essential for proper treatments to be instituted. In this paper, we present a computerized method for classifying five non-tumorous skin pigmentation disorders (i.e., freckles, lentigines, Hori's nevus, melasma and nevus of Ota) based on probabilistic linear discriminant analysis (PLDA). To address the large within-class variance problem with pigmentation images, a voting based PLDA (V-PLDA) approach is proposed. The proposed V-PLDA method is tested on a dataset that contains 150 real-world images taken from patients. It is shown that the proposed V-PLDA method obtains significantly higher classification accuracy (4% or more with p< 0.001 in the analysis of variance (ANOVA) test) than the original PLDA method, as well as several state-of-the-art image classification methods. To the authors' best knowledge, this is the first study that focuses on the non-tumorous skin pigmentation image classification problem. Therefore, this paper could provide a benchmark for subsequent research on this topic. Additionally, the proposed V-PLDA method demonstrates promising performance in clinical applications related to skin pigmentation disorders.

Líneas de demarcación pigmentarias tipo B en gestante / Type B Pigmentary Demarcation Lines in Pregnancy

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Acquired poikiloderma: proposed classification and diagnostic approach.

"Poikiloderma" is a morphologic and descriptive term referring to a combination of cutaneous atrophy, telangiectasia, and varied macular pigmentary changes that result in a mottled skin appearance. Its etiology includes both congenital and acquired causes. Many studies have reported different causes of acquired poikiloderma; however, no single well-defined classification has been explored to date. Herein, we analyze all the possible causes of acquired poikiloderma and propose an etiological classification that, hopefully, will lead to better characterization for this ill-defined condition. Moreover, this study presents a step-by-step approach to the management of patients with acquired poikiloderma and summarizes the key differentiating features for each individual cause, which may help in easy and precise diagnosis of different causes of acquired poikiloderma.

A simple scoring system for the diagnosis of palmo-plantar pigmented skin lesions by digital dermoscopy analysis.

BACKGROUND: Many research groups have recently developed equipments and statistical methods enabling pattern classification of pigmented skin lesions. To differentiate between benign and malignant ones, the mathematical extraction of digital patterns together with the use of appropriate statistical approaches is a challenging task. OBJECTIVE: To design a simple scoring model that provides accurate classification of benign and malignant palmo-plantar pigmented skin lesions, by evaluation of parameters obtained by digital dermoscopy analysis (DDA). PATIENTS AND METHODS: In the present study we used a digital dermoscopy analyser to evaluate a series of 445 palmo-plantar melanocytic skin lesion images (25 melanomas 420 nevi). Area under the receiver operator curve, sensitivity and specificity were calculated to evaluate the diagnostic performance of our scoring model for the differentiation of benign and malignant palmo-plantar melanocytic lesions. RESULTS: Model performance reached a very high value (0.983). The DDA parameters selected by the model that proved statistically significant were: area, peripheral dark regions, total imbalance of colours, entropy, dark area and red and blue multicomponent. When all seven model variables were used in a multivariate mode, setting sensitivity at 100% to avoid false negatives, we estimated a minimum specificity of about 80%. CONCLUSIONS: Simplicity of use and effectiveness of implementation are important requirements for the success of quantitative methods in routine clinical practice. Scoring systems meet these requirements. Their outcomes are accessible in real time without the use of any data processing system, thus allowing decisions to be made quickly and effectively.

Reticulate pigmentary disorders.

Reticulate pigmentary disorders is a term that is loosely defined to include a spectrum of acquired and congenital conditions with different morphologies. The presentations vary from the reticular or net like pattern to the" freckle like" hyper and hypopigmented macules that are usually restricted to the true genetic "reticulate" pigmentary disorders. There is little clarity on this topic and related terms, in major dermatology textbooks. Hence, to harmonize the different entities we feel that the term "mottled pigmentation" could be used to include reticulate pigmentary disorders (acquired and congenital), dyschromasias and the disorders with a reticular pattern. The genetic reticulate pigmentary disorders can also be classified according to the gene loci which in the majority of cases are localized to keratin 5/14. A more useful clinical method of classification is based on the regional distribution, which includes facial, truncal, acral or flexural types. In this review we will largely focus on the inherited reticulate pigmentary disorders.

Effect of environmental tobacco smoke from smoker parents on gingival pigmentation in children and young adults: a cross-sectional study.

BACKGROUND: Non-smokers exposed to environmental tobacco smoke (ETS) absorb nicotine and other compounds just as smokers do, and as the exposure to ETS increases, the level of these harmful compounds in the body also increases. The ill effects of ETS range from gingival pigmentation to lung cancer and death. The exposure to ETS is difficult to quantitatively measure and has been approximated by self-reported estimates, primarily of the smoking history of spouses. However, the documentation of gingival pigmentation in non-smokers is meager and has remained contentious. We aimed to assess the effects of ETS from smoker parents on gingival pigmentation in children and young adults and assess the urine cotinine levels in these individuals. METHODS: A total of 153 non-smoking participants with ≥1 smoker parent were randomly selected from the outpatient Department of Periodontics, Bangalore Institute of Dental Sciences and Postgraduate Research Center, Bangalore, India. These participants were divided into three groups based on age, and the smoking history of parents was established by an interview with participants and parents. The degree of gingival pigmentation of participants was assessed by using the gingival pigmentation index and a standardized digital oral photograph. A urine analysis was conducted to assess levels of cotinine. The κ statistic was performed for interexaminer agreement, and χ(2) and Fisher exact tests were used for statistical analyses. RESULTS: The prevalence of gingival pigmentation in passive smokers was statistically significant (P <0.05). Increased levels of urinary cotinine were observed in all three groups with the highest levels in group 3 (19 to 24 years old). CONCLUSION: This study depicts the effects of ETS on gingival melanin pigmentation.

Dowling-Degos disease: case report and review of the literature.

Dowling-Degos disease (DDD) is an unusual pigmentary disorder usually caused by mutations in keratin 5. A 44-year-old woman in good general health presented due to the recent appearance of numerous pigmented macules on her axillary and anogenital skin. A biopsy showed lacy, finger-like epidermal extensions into the dermis which were heavily pigmented and associated with tiny cysts or dilated follicles. We view DDD as part of a spectrum of disorders which are morphologically related but vary in location and time of expression. In addition, both the clinical and histological differential diagnostic considerations are extensive.

Disorders of pigmentation.

Skin color is highly individual and the variations are controlled by numerous genes. The different skin colors result from the size and number of melanosomes and do not mirror the amount of melanocytes. Disorders of pigmentation can result from migration abnormalities of melanocytes from the neural crest to the skin during embryogenesis. In addition, impairment of melanosome transfer to the surrounding keratinocytes, an alteration in melanin synthesis and a defective degradation or removal of melanin may lead to abnormal skin pigmentation. Immunologic or toxic mediated destructions of melanocytes can end in pigmentation disorders. Disorders of pigmentation are classified in hypo- or hyperpigmentation which can occur as a genetic or acquired disease. They can manifest locally or diffuse. Congenital hypopigmentation can be restricted to the skin as in piebaldism or they represent a systemic disease as in Menkes disease or phenylketonuria. Localized hypo- or hyperpigmentation in children may serve as markers for systemic diseases. Ash-leaf hypopigmentation are characteristic for tuberous sclerosis and more than 5 café-au-lait spots suggest neurofibromatosis 1 (von Recklinghausen disease). The most common autoimmune-induced depigmentation is vitiligo. Generalized hyperpigmentation only rarely reflects a primary genetic disorder but is most often from acquired diseases as in Addison disease, secondary hemochromatosis or primary biliary cirrhosis. Treatment of pigmentation disorders are based on a diagnosis which sometimes allow a specific intervention. Cosmetically acceptable results are difficult to obtain.

Facomatosis pigmentovascularis: revisión y nueva clasificación / Phacomatosis pigmentovascularis: review and new classification

La facomatosis pigmentovascularis es un síndrome infrecuente caracterizado por la asociación de un nevus vascular con un nevus pigmentario. Su etiología es desconocida. Se ha propuesto un modelo genético de didimosis o manchas gemelas. La clasificación previa establece cinco categorías, que a su vez se subdividen en a) cuando existe compromiso cutáneo y b) cuando existe compromiso cutáneo y sistémico. Se ha propuesto una nueva clasificación, más simple, que resume las 10 categorías previas en tres tipos definidos: facomatosis cesioflammea, facomatosis spilorosea y facomatosis cesiomarmorata. Además, agrega un cuarto tipo de FPV no clasificables. Se han descrito asociaciones con otras alteraciones de la piel, oculares, vasculares, neurológicas, inmunológicas y malformaciones, por lo cual es recomendable realizar un examen físico extenso y derivación a especialidades para descartar patologías asociadas. Presentamos el caso de una mujer de 27 años que presenta lesiones correspondientes a una facomatosis cesioflammea en la nueva clasificación.

Phacomatosis pigmentovascularis is an uncommon syndrome characterized by the association of a widespread vascular nevus with a pigmentary nevus. Its etiology is unknown. A twin spotting or didymosis genetic model has been proposed. The previous classification established five categories, further subdivided into a) when cutaneous involvement was present or b) when cutaneous and systemic involvement was present. A new, more straightforward classification has been proposed, which summarizes the ten previous categories into three distinct types: phacomatosis cesioflammea, phacomatosis spilorosea and phacomatosis cesiomarmorata. Furthermore, a fourth category of unclassifiable phacomatosis pigmentovascularis was added. Diverse associations of phacomatosis pigmentovascularis with other skin lesions, malformations, and ocular, vascular, neurological and immunological abnormalities have been described, hence the importance of an extensive physical examination and consultations to discard associated pathologies. We present the case of a 27 year old woman, diagnosed with phacomatosis cesioflammea, based on the new classification.

[Molecular basis of pigmentation disorders in skin diseases]. / Molekularne podloze zaburzen pigmentacji w chorobach skóry.

Skin disorders connected with pigmentation disturbances are most frequent dermatological problems. Different mechanisms are involved in these changes, mainly those which regulate melanocyte function. In this work we focused on molecular basis of pigmentation disorders in dermatological diseases that present clinically with hyperpigmentation (lentigo senilis, Riehl melanosis, seborrhoic keratosis, fibroma, café-au-lait patches melasma, atopic dermatitis) or hypopigmentation (vitiligo, albinism).

[Kindler syndrome. A new bullous dermatosis]. / Kindler-Syndrom. Eine neue bullöse Dermatose.

The Kindler syndrome is a new form of inherited epidermolysis bullosa and the first genodermatosis caused by a defect of the focal adhesions. Kindlin-1, the deficient protein, plays an essential role in integrin activation and in the adhesion of keratinocytes to the extracellular matrix. The adhesion defect leads to skin blistering which begins at birth and ameliorates with age, and to mucosal fragility which leads to scarring and stricture formation. Skin atrophy and poikiloderma develop progressively. Photosensitivity is rather mild, but squamous cell carcinomas develop on sun-exposed areas mainly after the age of 40 years. The most important differential diagnoses are epidermolysis bullosa with mottled pigmentation and dystrophic epidermolysis bullosa. Management aims to treat the symptoms and prevent complications.

Digital photographic imaging system for the evaluation of various facial skin lesions.

In dermatology, various imaging modalities have been developed as an assistant tool to objectively evaluate the treatment efficacy of facial skin lesion. In this study, we propose a digital photographic imaging system the evaluation of various facial skin lesions in order to maximize the clinical evaluation efficiency by integrating various independent imaging modalities. Our imaging system provides four different digital color images, such as standard digital color image, parallel and cross polarization digital color image, and UV-A induced fluorescent digital color image. In conclusion, by analyzing the color information and morphological features, we were able to simultaneously evaluate various skin lesions with one imaging system.

Polarization color imaging system for on-line quantitative evaluation of facial skin lesions.

BACKGROUND: A number of studies have been performed for accurate evaluation of chromophores in skin lesions. Qualitative methods are subjective and cause user-dependent error in evaluation. Quantitative methods have limitations for widely distributed skin lesions due to poor spatial resolution, potential skin blanching, and difficulty in relocating identical sites for subsequent measurements and analysis. OBJECTIVE: The objective was to develop a new imaging modality that provides both qualitative and quantitative methods to evaluate widely distributed skin lesions. METHODS: We have developed a prototype polarization color imaging system named "DermaVision," which provides quantitative on-line image analysis of polarization color images. Herein, we describe the hardware and software of DermaVision in terms of its performance and usefulness for dermatologic applications. RESULTS: Polarization color images were successfully acquired from patients with vascular or pigmented skin lesions. The erythema and melanin index images were successfully computed and quantitatively confirmed the degree of erythema and pigmentation in the skin lesions. CONCLUSION: We believe that DermaVision can be a useful auxiliary tool in dermatology because it simultaneously provides both qualitative and quantitative images of skin lesions.

Griscelli syndrome type 2; a pediatric case with immunodeficiency.

A 3.5 month-old girl was admitted with silvery gray hair, light colored skin, recurrent diarrhea, chest infections, hepatosplenomegaly, episodes of pancytopenia, and hemophagocytosis in the bone marrow. Light microscopy of hair showed characteristic large and irregular clumps of melanin in the middle of hair shaft. Peripheral blood smear examination did not show giant granules in granulocytes. On the basis of these clinical and laboratory findings, Griscelli syndrome was diagnosed. The child succumbed to infection during an accelerated phase of the disease.

Macro-micro dermatology: erythematous papules and lentigo-like macules--a new entity?

Galli-Galli disease is usually characterized by reticulate hyperpigmentation of the flexures. Rare patients may present without this finding, instead having only localized erythematous papules and brown, lentigo-like macules on the trunk and extremities. Histological changes consist of elongated and in part hyperpigmented rete ridges and areas of acantholysis.