What Causes White Nails?

Discussion The nail matrix covers the area of the nail plate, and extends proximally in a crescent moon shape with the edges of the crescent extending proximally and inferiorly toward the underlying bone. The nail matrix is a multilayered epithelium that physiologically produces keratinization and gives rise to the nail plate. The distal matrix forms the lower 2/3s of the nail plate and the proximal matrix forms the upper 1/3 of the nail plate. the thickness of the nail plate is proportion to the matrix’s thickness. The nail plate’s free edge contour follows the shape of the nail’s lunula. Melanocytes occur in the nail matrix but are 1/6 as numerous as those in the skin epidermis. In the distal matrix about 50% are activable and 50% are dormant. In the proximal matrix almost 100% are dormant. If activated, the melanocytes produce pigment, which is transferred to the keratin and a colored area of the nail plate occurs. Regrowth of fingernails takes about 6 months and toenails can be 12-18 months. It usually takes 4-8 weeks for any incident to even begin to show up on the nails. Learning Point Leukonychia means white nail. It occurs when the normally translucent color is gone and the nail plate looks totally or partially white. True leukonychia has abnormal keratinization of the nail plate so that the nail plate appears white because of changes in the light diffraction. The coloring does not change with pressure, and the opacity changes with nail growth....
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news