Causes.  —  1.  Predisposing. — The  comparative  smallness  of
the  larynx  and  trachea  in  infancy  and  early  childhood.  After  the
third  year  the  caHber  of  the  trachea  enlarges  rapidly,  and  the
liability  to  Croup  correspondingly  diminishes.  There  is  also  a
clear  predisposition  to  it  in  some  patients  and  families.  2.  Ex-
citing.— Exposure  to  cold,  sudden  changes  of  temperature,  wet
feet,  poor  or  scanty  food,  especially  the  adoption  of  improper
diet  on  weaning,  keeping  a  child  in  a  room  the  floor  of  which
has  been  newly  washed;  dark,  damp,  low- lying  locaHties.  The
disease  is  most  frequent  in  winter  and  spring.
Symptoms.  —  The  early  symptoms  resemble  those  which
initiate  an  attack  of  Measles — fever.  Hoarseness,  and  a  dry  bark-
ing cough  of  that  distinctive  character  which  necessarily  occurs
when  the  rima  glottidis  is  contracted.  Indeed,  this  cough  is  the
characteristic  symptom,  and  probably  exists  two  or  three  d&ys


Digitized  by  VjOOQIC


€16


THE   FAMILY   DOCTOR.
