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1.
The presence of acquired benign nevi is a risk factor for cutaneous melanoma, yet relatively little is known about the etiology of nevi. We have conducted a study of the prevalence of melanocytic nevi among 1146 white Vancouver (Canada) schoolchildren aged 6 to 18 years. Numbers of nevi per square meter of body surface area increase with age in children of both sexes. Male adolescents have more nevi than female adolescents on the head and neck as well as on the trunk, while prevalence in females is higher on the upper and lower limbs. This distribution parallels that of cutaneous melanoma in British Columbia adults. Nevi are more common in children on intermittently exposed body sites than on constantly or minimally sun-exposed sites. This suggests that exposure to strong intermittent sunlight in childhood (a risk factor for cutaneous melanoma) may also be important in the etiology of acquired benign nevi.  相似文献   

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The association between prevalence of benign melanocytic nevi and a number of skin cancer risk factors was examined among 913 white Vancouver (Canada) school children aged 6 to 18 years. Subjects with light skin, with a propensity to burn rather than tan in the sun, and with numerous or severe sunburns in the previous 5 years had significantly higher nevus counts than individuals without these characteristics. Subjects who acquired deeper tans tended to have fewer nevi than those who did not tan. Finally, children who freckled had higher nevus counts than those who did not freckle. These findings in children are similar to those seen in studies of malignant melanoma among adults and suggest that strategies to reduce melanoma incidence should begin with young children.  相似文献   

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BACKGROUND AND METHODS--Prevalence of benign melanocytic nevi (moles) has been shown to be a major predictor of malignant melanoma. In this study the prevalence of moles in a group of 2140 children, aged 4 to 11 years, was determined. A standard questionnaire was completed by the parents of each child and included information on environmental and life-style factors. Examination data for each child were linked to the data obtained from the questionnaire. RESULTS--Prevalence increases rapidly throughout childhood and studies of children may indicate which factors contribute to mole development. Boys had more moles than girls, as did white children when compared with other ethnic groups. Prevalence of moles increased with age in children of both sexes. Among whites, skin color had little influence on mole prevalence. The following characteristics, however, were associated with an increased prevalence of moles: a propensity to burn rather than tan, a history of sunburn, a tendency to freckle, and a life-style involving increased sun exposure. A striking positive association between prevalence of moles and number of foreign holidays in a hot climate was observed. This association was independent of a history of sunburn. CONCLUSIONS--The study supports the hypothesis that environmental factors influence the prevalence of moles in childhood.  相似文献   

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Abstract:  This study investigated the numbers of melanocytic nevi in Turkish children and adolescents. The research was conducted on 2783 subjects (age range, 7–14 yrs) at three elementary schools in Malatya, Turkey (latitude 38°N). Numbers of melanocytic nevi per subject were counted using a standard international protocol. Comparisons were made with subjects categorized according to age, sex and skin type. The mean melanocytic nevus count was 1.07 ± 2.37. A significant positive correlation was found between nevus count and age (p < 0.001). The mean count for boys was significantly higher than that for girls (p   < 0.001). Subjects with skin type II had a higher mean melanocytic nevus count than the other three groups. This is the first study related to numbers of melanocytic nevi in Turkey. The findings reveal that Turkish children and adolescents have few melanocytic nevi compared to those elsewhere in the world. In line with previous reports on other populations, analysis showed that older age, skin type II, and male sex are associated with higher melanocytic nevus counts. The results underline the importance of ethnic background in melanocytic nevus development.  相似文献   

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Epidermal naevus of the acanthokeratolytic (epidermolytic) type is a mosaic birth defect. The underlying mutation may also be present in the gonads and can then be transmitted to the next generation. The affected child, however, will always show a diffuse involvement of the entire body in the form of bullous congenital ichthyosiform erythroderma. In other words, the phenotype can be transmitted, but not the mosaic. This explains why acanthokeratolytic epidermal naevus always affects the parent and never the child when it is observed in a family together with bullous congenital ichthyosiform erythroderma.  相似文献   

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鲜红斑痣(nevus flammeus),又称葡萄酒色斑(port wine stains),由扩张的毛细血管组成,是最常见的先天性血管畸形,发病率约为0.3%~0.5%,无明显性别差异.损害可发生于体表各部,但以面、颈和头皮多见.通常在开始时为粉红色斑片,随着年龄增长颜色逐渐加深,可呈鲜红或紫红色,皮损渐增厚,在成年期可出现结节.  相似文献   

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对晕痣和痣细胞痣进行了 OKT6阳性细胞的免疫组化观察 ,结果表明晕痣表皮内 OKT6阳性细胞数显著多于痣细胞痣 ,提示 OKT6阳性细胞可能在晕痣的自身免疫发病机制中起着一定作用  相似文献   

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Recently it has been reported that Spitz's nevus possesses a deranged melanogenesis with formation of the spherical melanosomes also seen in superficial spreading melanoma (SSM) and dysplastic melanocytic nevus (DMN). To characterize the nature of Spitz's nevus, immunohistochemical studies were carried out in 9 cases of this condition using monoclonal antibodies (MoAbs) which identify (a) human melanosome-associated antigen (HMSA-1 and HMSA-2), (b) S-100 protein (α and β subunits), (c) Leu-7 (HNK-1), (d) β2 microglobulin (B2MG), and (e) neuron specific enolase (NSE). In contrast to SSM and DMN, none of the 9 cases showed any significant reactivity with MoAbs HMSA-1 and HMSA-2. Similar to cutaneous malignant melanoma (CMM) and DMN, and unlike common melanocytic nevus (CMN), anti-S-100 protein α subunit MoAb reacted from moderately to intensely with Spitz's nevus, and anti-S-100 protein β subunit MoAb reacted weakly. Anti-B2MG MoAb was reactive with 8 of 9 cases. Only one case showed cytoplasmic reactivity to anti-Leu-7 MoAb. Polyclonal NSE was found in 7 cases at varying intensities. Our immunohistochemical study indicates the distinct, benign neoplastic nature of Spitz's nevus which has immunoreactivities differing from those of CMM, DMN and CMN.  相似文献   

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Balloon cell nevus (BCN) is a histopathological variant of cutaneous acquired melanocytic nevi characterized by junctional and/or dermal nests of large cells with a clear and foamy cytoplasm which has rarely been described in children. Three cases of BCN firstly reported on the scalp in two pediatric patients are presented along with a literature review. Dermoscopy is particularly indicated in those pigmented lesions showing a yellowish hue, in ruling out in real time those disorders that may clinically be similar such as xanthogranuloma and sebaceous nevus, and to suggest the diagnosis of BCN. The final diagnosis, however, is established by histopathological examination.  相似文献   

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目的:探讨儿童斑秃的发病与骨密度异常的关系。方法:对71例斑秃患儿[斑秃分为点状(<1cm)秃发、斑状(>1cm)秃发和普秃]及46例成人3种类型斑秃患者进行骨密度,血清锌、钙和铁测定比较及生活习惯调查。结果:儿童组斑秃患者中骨质疏松的阳性百分率明显高于成人斑秃组(P<0.001);儿童组斑秃患者中血清微量元素下降的百分率高于成人斑秃组,尤以锌元素下降明显,但无统计学意义(P>0.05);儿童组斑秃患者中血清锌和钙水平显著低于正常水平(P<0.05);骨密度下降斑秃患儿伴有“常吃零食”和“挑食”的不良生活习惯,并具有除斑秃以外的临床表现。结论:儿童斑秃,尤其是点状脱发和斑状脱发发病与骨密度异常的关系密切,此外血清锌、钙水平降低及不良生活习惯也与儿童斑秃发病有关。  相似文献   

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The objective was to estimate the prevalence of melanocytic nevi (MN) in children and to determine their dermoscopic characteristics and relationship with anatomic location and environmental and constitutional factors. The population was a randomly selected sample of 144 children who attended primary schools in Naples, Italy. Before physical examination of the children, standardized interviews were conducted with their parents. Follow‐up interviews of both the children and parents were conducted 1 year later. Photographic and dermoscopic images were obtained. Boys had more MN than girls; 465 MN (55.6%) were observed in boys and 371 (44.4%) in girls (p < 0.05). The trunk and neck were the most common locations of MN (p < 0.001). The main dermoscopic feature of all MN observed was a globular pattern (p < 0.001). A significant correlation between duration of sunbathing and MN counts was revealed (p < 0.05). At 1‐year follow‐up, 118 new MN were identified in 66 children. The trunk and neck areas were the most common regions involved in the appearance of new MN (n = 68, 57.6% of all new MN, p < 0.001). The new MN count was significantly higher in children who reported more sunbathing (p < 0.001). Changes in the dermoscopic pattern were observed in 45 persistent MN, demonstrating more MN with a reticular‐globular pattern, especially on the trunk, neck, and upper extremities (p < 0.001). MN development in early life is the result of complicated relationships between nevus evolution, anatomic location, and environmental and constitutional factors.  相似文献   

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BACKGROUND: Nevi are potential precursors of malignant melanoma and are important risk factors for the development of the disease. Childhood may be a critical time for the formation and evolution of nevi. OBJECTIVES: To document the development of new nevi and to document the clinical and dermoscopic changes in index nevi in school children during a 1-year follow-up. METHODS: Digital photographs and dermoscopic images of the back of subjects were compared at baseline and 1-year follow-up to assess changes in nevi counts and in clinical and dermoscopic features of index nevi. RESULTS: Overall participation rate was 81% (42/52). 56.4% of study participants were found to have an increased number of nevi at 1-year follow-up. All nevi were small and clinically insignificant. Fifty percent of study participants were found to have dermoscopic changes in their index nevi at 1-year follow-up. Eighty-five percent of these changes were classified as subtle and 15.0% as obvious. CONCLUSIONS: A significant portion of students developed new nevi over the course of 1 year. Most index nevi remained stable in pattern and structure. Benign dermoscopic changes occurred in 50.0% of index nevi. However, none of the dermoscopically changed nevi revealed any major changes and the overall nevus pattern remained unchanged. The relevance of these changes is uncertain and further follow-up may elucidate their significance.  相似文献   

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Summary Background The first manifestations of psoriasis begin in childhood in more than one‐third of patients. However, epidemiological data of juvenile psoriasis are lacking. Objectives To compare Dutch (NL group) and Singaporean (SG group) children with psoriasis with the aim of studying the characteristics of juvenile psoriasis and to highlight similarities and differences between these different ethnic groups. Methods Data were collected from 207 patients younger than 18 years diagnosed with psoriasis from Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands and the National Skin Centre, Singapore. Results A striking difference in familial distribution was found, with more Dutch children having an affected family member (73·3% vs. 13·6%). Presence of itch and triggering factors were more common among Dutch children (80% vs. 14·2% and 33·3% vs. 7·4%, respectively). However, both groups shared similar triggering factors like stress and infections. Other similarities included mean age at presentation (NL group 11·3 years; SG group 14·1 years) and gender ratio (NL group, M/F 1 : 1·1; SG group, M/F 1 : 1·4). Plaque psoriasis was the most common type in both cohorts while guttate and pustular psoriasis were rare. In both groups, the head, followed by the limbs, was the most common site involved. Similar proportions of children in both countries had nail involvement and psoriatic arthritis was rare. Conclusions The disparity in familial distribution may point to genetic differences between the two groups. Further studies to evaluate this difference in familial distribution may contribute to the understanding of the pathogenesis of psoriasis.  相似文献   

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Seborrheic keratosis can be associated with different neoplasms such as basal cell carcinomas, squamous cell carcinomas and melanomas. We describe an unusual case of a man who presented with a brown plaque on his back. The clinical diagnosis was melanoma. Histopathologic examination of the lesion revealed four neoplasms: a compound nevus, a junctional nevus, a superficial basal cell carcinoma and a seborrheic keratosis. Although this association most likely represents a chance phenomenon, we discuss the possibility that the seborrheic keratosis developed from the nevus, and that subsequently the junctional nevus and the basal cell carcinoma developed from the seborrheic keratosis.  相似文献   

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Baharestani MM  Ratliff CR 《Advances in skin & wound care》2007,20(4):208, 210, 212, 214, 216, 218-208, 210, 212, 214, 216, 220
Acutely ill and immobilized neonates and children are at risk for pressure ulcers, but a paucity of evidence-based research exists on which to base guidelines for clinical practice. Most prevention and treatment protocols for pressure ulcers in the pediatric population are extrapolated from adult practice. Clinical practice guidelines for prevention and treatment of pressure ulcers that specifically address the needs of the pediatric population are needed. The purpose of this article is to highlight the research that is currently available and to identify gaps that need to be addressed so that science-based, age-appropriate prevention and treatment pressure ulcer guidelines can be developed.  相似文献   

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