الفهرس | Only 14 pages are availabe for public view |
Abstract Dermoscopy is an aiding diagnostic tool that allows the in vivo evaluation of colors and microstructures of the epidermis, the dermo-epidermal junction, and the papillary dermis which are not visible to the naked eye. Its idea depends on trans-illumination of a lesion and studying it with a high magnification. Old dermoscopes required application of certain oil over the lesion to be examined while new dermoscopes are provided with polarized light, rendering the fluid placed on the lesion unnecessary for inspecting pigmented skin structures. Dermoscopes are classified into dermoscopes without image capturing facility, dermoscopes with image capturing facility and dermoscopes with image capture facility and analytical capability. In assessing dermoscopic images, both global and local features can be recognized. Global features include reticular pattern, globular pattern, cobblestone pattern, homogenous pattern, starburst pattern, parallel pattern, multicomponent pattern, lacunar pattern, unspecific pattern. Local features include, pigment network, dots and globules, streaks, blue-whitish veil, pigmentation, hypopigmentation, regression structures, vascular structures, milia like cysts, comedo-like openings, exophytic papillary structures, red lacunas, leaf-like areas, central white patch. There are different dermoscopic diagnostic procedures including, the twostep dermoscopy algorithm, ABCD rule of dermoscopy, the 7-point checklist, rule of three points, Menzies scoring method, pattern analysis, CASH algorithm and stratification of risk level. Dermoscopy is an important tool for diagnosing benign and malignant melanocytic diseases and for detecting and differentiating the several types of skin cancer and other inflammatory, infectious and parasitic dermatoses .Dermoscopy has been utilized in recent years for diagnosing various hair and scalp diseases. It allows visualization of hair and hair follicle at high magnification . Under the right conditions, dermoscopy allows us to observe the vascular features of many different types of skin lesions. The visualization and identification of vessels with a characteristic morphology can be the key to diagnosis, Some of the more characteristic associations are the presence of :- - Arborizing vessels: In Basal cell carcinoma. - Dotted vessels: In Spitz nevus or melanoma, psoriasis, squamous cell carcinoma. - Erythematous blush:, dysplastic nevus. - Linear irregular vessels: In Melanoma. - Comma vessels: In Compound or dermal nevus. - Polymorphous atypical vessels: In Melanoma. - Hairpin vessels:In Regular seborrheic keratosis and keratinizing tumors. - Glomerular vessels: In Bowen’s disease, melanoma or stasis dermatitis - Milky red globules: In Melanoma. - Crown vessels: In Sebaceous gland hyperplasia. The recognition of distinctive vascular features can be of great help in the diagnosis of many types of skin lesions. |