RT Book, Section
A1 Kos, Liborka
A2 Rudolph, Colin D.
A2 Rudolph, Abraham M.
A2 Lister, George E.
A2 First, Lewis R.
A2 Gershon, Anne A.
SR Print(0)
ID 7033503
T1 Chapter 366. Disorders of Nails
T2 Rudolph's Pediatrics, 22e
YR 2011
FD 2011
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-149723-7
LK accesspediatrics.mhmedical.com/content.aspx?aid=7033503
RD 2024/04/23
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.