View report page

52
Reaction appears after 12 to 36 hours and takes the form
of swelling and redness at the site of injection. The reaction is
clearly visible at the end of the second day becoming progressively
intense and attaining its maximum after 3 to 5 days. It then
disappears slowly leaving behind a brown patch, which desquamates
in fine flakes and does not finally disappear until after three to
six weeks. The zone of reaction is generally very small, from 1 to
2 centimetres in diameter but is rarely painful.
The person who does not possess any anti-toxin in his blood
will show an intense reaction, the intensity being inversely proportional
to the quantity of anti-toxin present. A person possessing
sufficient anti-toxin to neutralise the toxin injected does not
show any local reaction at the site of injection.
By means of this Schick test, which has been proved to be
thoroughly satisfactory in its application, susceptibles can easily
be determined and proper steps taken in the first place to prevent
their exposure to infection and secondly to render them immune to
diphtheria.
Interesting observations have been made, particularly in
New York and more recently in this councry, which have shown
the susceptibility of persons at various ages.
Somewhat similar results have been obtained in this country,
although the actual percentages vary, as Dr. Robertson of Edinburgh
has pointed out, according to the social status of the children.