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Results for “Skin Pigmentation”

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PubMed2003

[Increased skin pigmentation in patients with chronic renal failure undergoing hemodialysis infected with the hepatitis C virus].

BACKGROUND: Skin pigmentation is commonly found in patients with chronic renal failure (CRF). This symptom is also one of the most evident features of Porphyria Cutanea Tarda (PCT). Hepatitis C virus (HCV) is an important precipitating agent of this disease, which has been described in patients undergoing hemodialysis (HD). In this paper, we intend to evaluate the prevalence of difuse skin hyperpigmentation in patients with CRF infected with the HCV. METHODS: We developed a transversal study with 47 patients (mean age 50,35 + 15,16 years; 31 men and 16 women) who were on hemodialysis in march of 2001 at the Unit of Dialysis of Hospital de Cl nicas de Porto Alegre. Patients were divided in two groups: group 1, anti-HCV positives (n=17), and group 2, anti-HCV negatives (n=30). RESULTS: The prevalence of skin hyperpigmentation related to HD was 36,2% (n=17). There were 10 patients (58,8%) in group 1 and 7 (23,3%) in group 2 (Odds Ratio of 2,52 and 95% Confidence Interval of 1,18-5,4; p<0,05). Among patients who have undergone HD for until 36 months (n=24), 6 were anti-HCV positive and 3 of tham (50%) mentioned skin pigmentation (OR of 9,0 and 95%CI of 1,1-71,0; p<0,05). Patients from group 2 who referenced the symptom have been on HD for a longer period than those who did not (63,85 + 11,9 vs. 29,3 + 4,71 months; p<0,05). CONCLUSIONS: HCV infection was associated with increased skin hyperpigmentation in patients with CRF undergoing HD. Time on treatment was also associated with this signal.

Brazil↗

PubMed1992

Cutaneous blood flow measurements for the detection of malignancy in pigmented skin lesions.

This work assesses cutaneous blood flow measurements as an adjunct in the differentiation between malignant and benign pigmented skin lesions. Blood flow in pigmented lesions and in their vicinity was measured by laser Doppler flowmetry (LDF), which measures the superficial skin blood flow. The lesions were then excised and histologically examined. While LDF readings for most of the benign lesions did not differ from those of control measurements, basal cell carcinomas showed a significant elevation and so did the melanomas (p less than 0.0001). Moreover, comparing the two groups of malignant lesions, namely the melanomas and basal cell carcinomas, the melanomas showed a significantly higher elevation (p less than 0.02). These results suggest that LDF may serve as an additional tool in the diagnosis of pigmented skin lesions: the probability of malignancy is low when LDF readings show no difference from adjacent normal skin; on the contrary, elevated readings suggest an increased likelihood of malignancy.

Blood Flow Velocity↗

PubMed2005

Fractal characterisation of boundary irregularity in skin pigmented lesions.

A growing literature shows researcher's interest in fractal analysis, arising from its ability to describe and characterise quantitatively the complexity of several tumour profiles. The aim of the work was to investigate the fractal properties of skin pigmented lesion boundaries. Although melanoma is one of the most aggressive tumours, early detection and a high rate of diagnostic accuracy, followed by timely excision, can allow complete recovery in melanoma patients. A modified approach to fractal dimension estimation was performed that was able to consider, in a data fit procedure, the range in which lesions show fractal properties. Identification of this zone is the most important step towards a correct fractal analysis procedure. The method was checked against a known fractal dimension object (Koch's curve) with an error of 0.007. The fractal dimension was estimated in 110 skin pigmented lesions and showed a significantly increasing linear regression (p < 0.05), from common naevi to naevi with dysplasia to melanomas. This result is important for screening, as it can inform the decision to excise precociously malignant lesions or to avoid unnecessary removal of benign ones. The limitations of the method are discussed.

Diagnosis, Differential↗

PubMed1993

Triple structural mosaicism of chromosome 18 in a child with MR/MCA syndrome and abnormal skin pigmentation.

A case of triple mosaicism involving chromosome 18 is described in a girl with abnormal skin pigmentation similar to hypomelanosis of Ito. The karyotype is 46,XX, -18, + del(18)(p11.23-->pter)/46,XX, -18, + idic(18)(p11.23)/46,XX, -18, + r(18). The patient displays some clinical features of monosomy 18p and a few signs of trisomy 18q. Our case illustrates a non-random association of chromosomal mosaicism with abnormal skin pigmentation.

Abnormalities, Multiple↗

PubMed2001

Effects of all-trans retinoic acid on melanogenesis in pigmented skin equivalents and monolayer culture of melanocytes.

The effects of all-trans retinoic acid (RA) on melanogenesis and the mechanism of its action in topical treatment have not been elucidated. The purpose of this study was to determine the effects of RA on melanogenesis in the pigmented skin equivalent as well as in monolayer culture of melanocytes, and to determine whether RA, hydroquinone (HQ), and hydrocortisone (HC) show synergistic depigmenting effects in combined treatments of each other. The suppressing effect of RA on melanogenesis was not observed in pigmented skin equivalents and monolayer culture of murine and human melanocytes, although HQ showed strong inhibition of melanogenesis. The synergistic effects between RA, HQ, and HC were not particularly seen. The results suggested that RA neither has direct inhibitory effects on melanogenesis of melanocytes, nor influences the cell-cell interactions between melanocytes, keratinocytes and fibroblasts, such as paracrine actions with regard to melanin production. The role of RA in bleaching treatments appears to be in other specific actions, such as promotion of keratinocytes proliferation and acceleration of epidermal turnover.

Animals↗

PubMed1993

Replacement of chlorpromazine with other neuroleptics: effect on abnormal skin pigmentation and ocular changes.

This paper describes the outcome of 15 patients with chlorpromazine (CPZ)-induced abnormal skin pigmentation (ASP) in whom CPZ was replaced with other neuroleptics for three to 13 years. Complete resolution of ASP occurred over a period of six months to five years following substitution with haloperidol (four patients), levomepromazine (three patients), trifluoperazine (one patient), thioproperazine (one patient) as the sole neuroleptic, by a combination of two of the three phenothiazines (four patients) or haloperidol plus pipotiazine (one patient). Resolution was maintained during the remainder of the follow-up period. In one patient, at final follow-up, marked improvement was present three years after CPZ was replaced with levomepromazine. Bilateral lenticular pigmentary deposits persisted in all eight patients examined 3.3 to 13 years after replacing CPZ and less than three months to nine years after resolution of ASP; improvement was noted in only one of these patients. Bilateral endothelial corneal deposits, present in five patients while on CPZ therapy, had disappeared in two patients seven and 13 years, respectively, after replacing CPZ; improvement was noted in two other patients. These findings indicate that: 1. CPZ-induced ASP is completely reversible in most, if not all, patients if CPZ is withdrawn; 2. a variety of neuroleptics including other phenothiazines can be used to replace CPZ without risk of re-emergence of ASP; 3. CPZ-induced lenticular changes persist whereas corneal changes may resolve slowly over a period of many years following replacement of CPZ; 4. ASP and ocular changes induced by CPZ may be subserved by two different pathophysiological mechanisms.

Adult↗

PubMed1990

[Diagnosis of pigmented skin lesions using surface microscopy].

The clinical diagnosis of cutaneous pigmented tumors is often difficult. Surface microscopy represents an interesting approach to this problem. For this in vivo investigation, a stereomicroscope, a glass slide and immersion oil are used. In order to improve the clinicopathological correlation of pigmented skin lesions, morphological criteria discerned by surface microscopy--such as pigment network or black dots--were compared with the corresponding histological features. Surface microscopy opens a new dimension for the diagnosis and differential diagnosis of malignant melanomas, dysplastic nevi, or non-melanocytic pigmented tumors, and allows a better pre-operative assessment of these lesions.

Humans↗

PubMed2000

Teledermoscopy--results of a multicentre study on 43 pigmented skin lesions.

We performed a multicentre study to evaluate the agreement between the direct clinical diagnosis and the telediagnosis of 43 cutaneous pigmented lesions. Digital clinical and dermoscopic images of the 43 pigmented skin lesions (11 melanomas, 23 melanocytic naevi, three basal cell carcinomas, three lentigines, two seborrhoeic keratoses and one angiokeratoma) were sent by email to 11 colleagues (six dermatologists, two residents in dermatology, one oncologist, one specialist in internal medicine and one general practitioner) in 10 centres. These 11 colleagues had different degrees of experience in dermoscopy. With histopathology as the gold standard, an average of 85% of the telediagnoses were correct, with results varying from 77% to 95%, whereas face-to-face diagnosis by an expert dermatologist was correct in 91% of cases. The kappa value for all participants ranged from 0.35 to 0.87. The results confirm that teledermoscopy can be a reliable technique for the diagnosis of pigmented skin lesions but one that will depend on the expertise of the observer.

Adolescent↗

PubMed1993

Vitiliginous vs pigmented skin response to intradermal administration of interferon gamma.

BACKGROUND AND DESIGN: Decreased sensitization and elicitation of contact allergens in vitiliginous skin has been described. This may be related to altered epidermal Langerhans cell migration with bound hapten to dermis and draining lymph nodes. The aim of the present study was to detect the potential ability of vitiliginous skin to respond to an in vivo immunologic stimulus such as intradermal injections of interferon gamma (IFN-gamma). Vitiliginous and normal pigmented skin of each patient was injected intradermally with 10 micrograms of recombinant IFN-gamma diluted in 0.1 mL of sterile water for 3 consecutive days. On day 5, punch biopsy specimens were obtained from the injected sites. Histologic and immunohistochemical staining was performed on all sections. The cryostat sections were stained with adenosine triphosphatase as well as with the indirect immunoperoxidase technique employing murine monoclonal antibodies to HLA-DR, ICAM-1, CD1, CD11a, and CD18. RESULTS: HLA-DR and ICAM-1 expression by epidermal cells, combined with perivascular accumulation of mononuclear cells with CD11a and CD18 expression, was observed in all sites injected with IFN-gamma. However, absence of an effect on the epidermal Langerhans cell population was noted only on the vitiliginous skin. CONCLUSION: The reactivity of depigmented and pigmented skin was found to be different after IFN-gamma administration, with fewer CD1-positive cells in the depigmented skin. As adenosine triphosphatase staining also showed fewer positive cells, it may be concluded that no effect on the migration of epidermal Langerhans cells was noted in the involved skin. This may shed light on the immunologic aberration seen in vitiliginous skin.

Adenosine Triphosphatases↗

PubMed1999

Sibling correlations of skin pigmentation during growth.

The present study is focused on the analysis of skin color correlations in a sample of 1039 siblings aged 4 to 20 years from the province of Biscay (Basque Country, Spain). Measurements were taken at the upper inner arm and forehead by means of an EEL DS29 Digital Unigalvo reflectance spectrophotometer fitted with filters 601, 605, and 609. The reflectance data were internally standardized according to sex and age of the individuals, and the analysis of the degree of similarity between siblings was based on the calculation of intraclass correlation coefficients. All 3 filters gave fairly high and statistically significant correlations regarding forehead skin color (between 0.28 and 0.45) for all types of siblings under consideration. However, with respect to filter 609 the arm reflectance values did not reveal correlation either between brothers (0.01) or between siblings (0.02), even though it did reveal correlation between sisters (0.29). When other filters or type of sibling were considered (also for arm), all coefficients happened to be statistically significant and relatively high (0.35-0.43). This study confirms that the degree of sibling resemblance with regard to skin pigmentation is influenced by growth factors and that the upper inner arm and the forehead skin patterns change with age in the sense that, during and especially after puberty, the coefficients of correlation are higher for arm reflectance than for forehead reflectance; the forehead is a site that is more influenced by environment.

Adolescent↗

PubMed1999

Morphologic changes of pigmented skin lesions: a useful extension of the ABCD rule for dermatoscopy.

BACKGROUND: Epiluminescence microscopy (ELM) significantly increases the early diagnosis of pigmented skin lesions (PSL) using established criteria and pattern analysis. The ABCD rule for dermatoscopy (ie, ELM) provides a simplified approach to the interpretation of ELM images on the basis of asymmetry (A), border (B), color (C), and dermatoscopic structure (D). OBJECTIVE: We set out to determine whether the diagnostic accuracy of the ABCD scoring algorithm can be significantly improved by incorporating information about morphologic changes of the lesion observed and provided by the patient. METHODS: We prospectively collected 356 small pigmented skin lesions (< 1 cm) including 73 (20.5%) melanomas. Before excision all patients were asked whether the lesion had changed in size, color, or shape within the last year or whether they experienced any sign of ulceration or spontaneous bleeding. ELM images of the lesions were evaluated according to the ABCD rule for dermatoscopy to yield a semiquantitative score. Accuracy of diagnosis was evaluated in terms of sensitivity, specificity, and area under receiver operating characteristic curves (AUC). RESULTS: The frequency of reported changes was significantly higher for melanomas than benign PSL (65.8% vs 29.7%, P < .001). In a multivariate model morphologic change was a significant independent predictor of malignancy (odds ratio = 3.17, 95% confidence interval [CI]: 1.96 to 5.14, P < .001). The mean final score achieved when using the enhanced ABCD-E criteria including morphologic change (E) was significantly higher for melanomas (5.7, 95% CI: 5.3 to 6.0) than benign PSL (2.9, 95% CI: 2.8 to 3.1, P < .001). Diagnostic accuracy was significantly higher when the lesions were evaluated by the enhanced ABCD-E criteria as compared with the standard ABCD score (AUC(ABCD) = 0.87 vs AUC(ABCD-E) = 0.90; P = .006). CONCLUSION: Information about morphologic changes of PSL as reported by the patient is a useful extension of the ABCD rule for dermatoscopy.

Adult↗

PubMed1999

Activating mutation of GS alpha in McCune-Albright syndrome causes skin pigmentation by tyrosinase gene activation on affected melanocytes.

McCune-Albright syndrome (MAS) is a sporadic disease characterized by café-au-lait spots, polyostotic fibrous dysplasia and hyperfunctional endocrinopathies. To elucidate the mechanism of skin pigmentation, melanocytes, keratinocytes and fibroblasts were primary cultured from the café-au-lait spot of a MAS patient. Then, mutational analysis and morphologic evaluation were performed. Also, cAMP level and tyrosinase gene expression in cultured cells were determined. Only Gsalpha mutation was found in affected melanocytes and the cAMP level in affected melanocytes was higher than that of normal melanocytes. The mRNA expression of tyrosinase gene was increased in the affected melanocytes. This study suggests that skin pigmentation of MAS results from activating mutation of Gsalpha in melanocytes and the mechanism involves the c-AMP-mediated tyrosinase gene activation.

Base Sequence↗

PubMed1989

MRI evaluation of pigmented skin tumors. Preliminary study.

Magnetic resonance imaging (MRI) was performed in 16 patients with pigmented skin lesions, seven with nodular melanomas, two with superficial spreading melanomas, two with subcutaneous melanoma metastases, and five with different benign pigmented nodular skin lesions. The results of MRI were compared with the histologic diagnoses. Signal intensities of the lesions were compared with subcutaneous fat, revealing a lower signal intensity of all lesions on T1-weighted images. Intensity measurements showed a significant (P less than .01) difference between benign and malignant lesions on T2-weighted images.

Adult↗

PubMed1996

Pupillary dilation and funduscopy with 1.0% hydroxyamphetamine plus 0.25% tropicamide (Paremyd) versus tropicamide (0.5 or 1.0%) as a function of iris and skin pigmentation, and age.

BACKGROUND: This study was designed to evaluate the effect of Paremyd, a combination of 1.0 percent hydroxyamphetamine hydrobromide and 0.25 percent tropicamide, on pupil size during binocular indirect ophthalmoscopy (BIO) upon 164 subjects of various skin pigmentation, iris color, and age. METHODS: Pupillary dilation and ease of performing BIO were measured after 30 minutes following instillation of a single drop of either Paremyd or tropicamide (1.0 or 0.5 percent) to an eye. Subjects were assigned to one of three groups; either Paremyd OU, or Paremyd OS and tropicamide (either 0.5 or 1.0 percent) OD, or Paremyd OD and tropicamide OS. Pupillary dilation was measured during BIO performed at a set illumination using a near point card. RESULTS: Results indicate that Paremyd is a significantly more effective dilator than either concentration of tropicamide alone. BIO was rated good to excellent for all dilating agents. As could be expected (based upon data from previous experiments), there was a small, but significant, negative correlation between dilation and age, skin pigmentation, and iris pigmentation. CONCLUSIONS: Paremyd, because of its superior effect upon dilation without side effects, can be the preferred agent used for routine single-drop dilation in all patients, independent of age, iris color, or skin color.

Adolescent↗

PubMed1997

Pigmented skin lesions in tyrosinase-positive oculocutaneous albinos: a study in black South Africans.

BACKGROUND: The aim of this study was to document the nature, prevalence, and distribution of pigmented skin lesions in tyrosinase-positive oculocutaneous albinism (ty-pos OCA), the most common recessive disorder in South Africa (overall prevalence, 1 in 3900). METHODS: Sixty-one black subjects with ty-pos OCA (mean age, 23 years) and 65 normally pigmented black control subjects (mean age, 29 years) were studied. RESULTS: Pigmented skin lesions not directly related to sun exposure included nevi and pigmented macules on the palms and soles. Melanocytic nevi, mostly on the trunk, were present in 82% of subjects with ty-pos OCA and in 71% of controls. The mean numbers were, however, greater in the ty-pos OCA subjects than in the controls (12 and 7, respectively), being closer to those reported in whites. Palmoplantar pigmentation was present in 75% of the control subjects, but in none of those with ty-pos OCA. The most striking sun-related lesions were dendritic freckles, which were present in 43% of ty-pos OCA subjects, and were characterized by an irregular branched shape, light to dark brown color, and large size (0.5-3.0 cm). Clinically, they resembled solar lentigines, but histologically the rete ridges were often flattened and there was no increase in the number of melanocytes. Solar keratoses occurred less frequently in ty-pos OCA subjects with dendritic freckles (50% vs. 73%), which confirmed the sun-protective role of the increased ability to form pigment. CONCLUSIONS: There were two major conclusions. Firstly pigmented nevi occur much more commonly in ty-pos OCA subjects than was previously thought, being similar in number to those found in white subjects. Secondly, dendritic freckles appear to represent a unique clinical and histologic entity found only on sun-exposed areas in ty-pos OCA subjects.

Adolescent↗

PubMed1980

Experimental hemosiderosis: relationship between skin pigmentation and hemosiderin.

Iron (totalling 7.5 mg per mouse in three doses) was injected into hairless mice to determine the relationship between skin pigmentation and hemosiderin deposition. The skin color reached its maximum 24 to 48 hours after the last injection and then gradually faded over the subsequent 8 months. In the skin, hemosiderin granules were present extracellularly between collagen bundles as well as within dermal macrophages, Langerhans cells and indeterminate dendritic cells of the epidermis. A larger amount of iron was deposited in the facial than in the dorsal skin, resulting in darker pigmentation of the former. This study suggests that brownish discoloration of skin in hemochromatosis might be attributable in some degree to accumulation of hemosiderin and that pronounced hyperpigmentation of the face in hemochromatosis might be due to increased activation of melanocytes by a high content of hemosiderin.

Animals↗

PubMed2003

Diagnostic and neural analysis of skin cancer (DANAOS). A multicentre study for collection and computer-aided analysis of data from pigmented skin lesions using digital dermoscopy.

BACKGROUND: Early detection of melanomas by means of diverse screening campaigns is an important step towards a reduction in mortality. Computer-aided analysis of digital images obtained by dermoscopy has been reported to be an accurate, practical and time-saving tool for the evaluation of pigmented skin lesions (PSLs). A prototype for the computer-aided diagnosis of PSLs using artificial neural networks (NNs) has recently been developed: diagnostic and neural analysis of skin cancer (DANAOS). OBJECTIVES: To demonstrate the accuracy of PSL diagnosis by the DANAOS expert system, a multicentre study on a diverse multinational population was conducted. METHODS: A calibrated camera system was developed and used to collect images of PSLs in a multicentre study in 13 dermatology centres in nine European countries. The dataset was used to train an NN expert system for the computer-aided diagnosis of melanoma. We analysed different aspects of the data collection and its influence on the performance of the expert system. The NN expert system was trained with a dataset of 2218 dermoscopic images of PSLs. RESULTS: The resulting expert system showed a performance similar to that of dermatologists as published in the literature. The performance depended on the size and quality of the database and its selection. CONCLUSIONS: The need for a large database, the usefulness of multicentre data collection, as well as the benefit of a representative collection of cases from clinical practice, were demonstrated in this trial. Images that were difficult to classify using the NN expert system were not identical to those found difficult to classify by clinicians. We suggest therefore that the combination of clinician and computer may potentially increase the accuracy of PSL diagnosis. This may result in improved detection of melanoma and a reduction in unnecessary excisions.

Adult↗

PubMedDate not supplied

Immunolocalization of lactoferrin in surgically resected pigmented skin lesions.

Lactoferrin (Lf) expression was determined immunohistochemically in 57 formalin-fixed paraffin-embedded bioptic samples obtained from an equal number of patients treated by surgery to remove pigmented skin lesions (nevi = 23; melanoma = 12; vulgaris and seborrhoeic warts = 12; basal cell carcinoma = 10); in addition, 10 specimens of normal skin were studied as control. On 3 mm thick sections, depigmentation and antigen retrieval procedures were performed. The Lf immunoreactivity was revealed by a rabbit anti-human Lf. Quantification of Lf immunoreactivity was performed using an intensity-distribution (ID) score. Melanocytic cells, regardless of their benign or malignant nature, were consistently stained, with no significant differences in the Lf ID-score between melanomas or nevi. A different intensity of Lf immunoreactivity was encountered in superficial portions of warts, exclusively inside squamous epithelial cells arranged in sheets or whorls of keratin. On the contrary, basal cell carcinomas were always unstained, while a slight Lf positivity was found in focal keratinized areas present in two tumours showing baso-squamous differentiation. The Lf immunoreactivity was localized in the cytoplasm and only occasionally in the nucleus. The biological meaning of Lf in these cases of human skin specimens remains unexplained, although it cannot be ruled out that Lf might be involved in the defense system against tumours, or alternatively, may be used by cells requiring iron availability for their turnover. Moreover, the immunohistochemical expression of Lf in melanocytic lesions might be also related to a Lf-melanin interaction. Finally, the involvement of Lf in skin squamous non-neoplastic elements could be related to its role as one of the molecules modulating an unspecific inflammatory or anti-oxidant response.

Adult↗