TY - CHAP M1 - Book, Section TI - Chapter 366. Disorders of Nails A1 - Kos, Liborka A2 - Rudolph, Colin D. A2 - Rudolph, Abraham M. A2 - Lister, George E. A2 - First, Lewis R. A2 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - Nail abnormalities are commonly an isolated benign finding related to infection or trauma. Occasionally, a nail change is a manifestation of an underlying generalized skin disorder, a systemic disease, or a congenital syndrome. Nail problems are often difficult to diagnose and are notoriously difficult to treat. Most diagnoses are made clinically. A nail matrix biopsy can also be performed, but the biopsy may itself cause a permanent nail dystrophy.Knowledge of nail anatomy is essential for an understanding of nail disease (see Fig. 356-2). The nail plate is firmly attached to the vascularized, innervated nail bed by two parallel, longitudinal grooves at either side. The cuticle firmly attaches to the proximal nail plate, preventing water, bacteria, and other irritants from entering the area of nail synthesis, the nail matrix. The proximal portion of the nail matrix lies underneath the proximal nail fold, 2 to 3 millimeters proximal to the cuticle. The lunula, or half-moon, is the visible distal portion of the matrix. Nails grow at an average rate of 0.5 to 1.2 mm/week. The complete replacement of a fingernail takes 6 to 8 months, whereas the replacement of a toenail takes 12 to 18 months. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/29 UR - accesspediatrics.mhmedical.com/content.aspx?aid=7033503 ER -