Study On The Dermoscopic Image Features Of The Hyperpigmentation Diseases

Dermoscopy was a clinical diagnostic tool,commonly used in dermatology. Dermoscopy can observed in vivo the fine structure of the epidermis, dermis junction and the papillary dermis, and dermoscopic findings based on color and morphological image may correspond to the pathology. Dermoscopy closely linked macroscopic clinical manifestations with microscopic histopathology.Hyperpigmentation diseases was a series of skin diseases characterized by pigmentation, and histopathology prsented pigment increase of the melanin and melanocytes of epidermis or dermis and other pathologic changes. Hyperpigmentation diseases including simple pigmented skin, melanocytic tumors, connective tissue disease, inflammatory skin diseases, and so on. The use of dermoscopy technique in the observation of morphology of hyperpigmentation diseases could explain the horizontal variation of pigmented sructure in the different pathological processes, which has important significance on better clinical dignosis ObjectiveExplore the dermoscopic feather of the hyperpigmentation disorders and explain the horizontal variation of the skin pigmented sructure in the different pathological processes. MethodsSelect 304 cases of hyperpigmentation diseases and observe dermoscopic image features. Count the frequency and percentage of the dermoscopic feature of different lesions, and that of related pathologic changes of lesions confirmed by histopathology,and the duration of lesions.All data were statistically analyzed by SPSS10.0 software. Analyze sensitivity of lesions,the correlation between dermoscopy and pathology,and the correlation between grew-blue dot /globular pigmented granule and the average duration of lesions. Rusults1.Simple pigmented skin:The primary dermoscopic features of melasma were uniform light brown or dark brown patches / dots,and that of simple lentigines were light brown pigment network.2. Melanocytic tumors: The primary dermoscopic features of acral melanocytic nevi were the parallel furrow pattern, fibrillar and latticelike pattern, and that of the non-acral melanocytic nevi were reticular pattern, globular pattern and homogeneous pattern.3. Interface dermatitis diseases: a. The primary dermoscopic features of discoid lupus erythematosus were follicular keratotic plug, perifollicular whitish halo,vascular structures, white scales and structureless whitish area, in which follicular keratotic plug, perifollicular whitish halo had a higher sensitivity.Systemic lupus erythematosus was similar to subacute lupus erythematosus in the primary dermoscopic features. The primary dermoscopic features of them were vascular structures, irregular granular pigment structure and structureless whitish area,in which vascular structures, irregular granular pigment structure had a higher sensitivity. b. The primary dermoscopic features of lichen planus were crystal white or yellowish-white Wickham stripes, dots or radial blood vessels, irregular granular pigment structure and brown structurless region. c. The primary dermoscopic features of melanosis were irregular granular pigment structure,follicular keratotic plug, perifollicular whitish halo, dust-like scales, blood vessels. d. Lichen Sclerosus: The primary dermoscopic features of extragenital lichen sclerosus were yellow-white structureless area, follicular keratotic plug, vascular structures, white patch and irregular granular pigment structure, and the proportion of each dermoscopic feather was higher than that of the genital lichen sclerosus. The genital lichen sclerosus was observed clover-like structure,and the latter was a characteristic change.4. There was a relation between dermoscopic feature and histological feature. Follicular keratotic plug corresponded to follicular hyperkeratosis.Perifollicular whitish halo corresponded to perifollicular fibrosis. Irregular granular pigment structure corresponded to melanophages.Vascular structures corresponded to telangiectasia.Structureless whitish area corresponded to dermal fibrosis. Wickham striae corresponded to wedge-shaped thickened granular layer.5. Irregular granular pigment structure correlated with the average course of lesions. The pigment pattern is more common in old lesions,and it was rare in the lesions with shorter duration.The difference was statistically significant. ConclusionThe study showed that several common hyperpigmentation disorders had respectively unique dermoscopic features. Different pigment patterns corresponded to specific pathological changes, which could be used to assist in the clinical diagnosis and differential diagnosis, guide further examination measures, to some extent, improve the accuracy of clinical diagnosis and reduce the number of histopathology biopsies.