With skin prick testing type 1 allergies, which are IgE mediated, are
diagnosed.
Drops of allergen solution are put on the forearm of the patient. With
sterile lancets, small amounts of the allergen penetrate the skin. If the
patient shows a sensitization after a few minutes there will be a little
swelling and redness. After 15-20 minutes, the diameter of the wheal is
measured. Considering the patients history together with the skin prick test
allows at the physician to diagnose allergy.
To make sure, the test is working, there always needs to be a positive control
(histamine solution) which has to result positive and a negative control which
has to remain negative.
There is no age limit to skin prick testing.
Prior to skin prick testing some drugs like for example antihistamines,
need to be stopped. If you need skin prick testing, Dr. Annette Gerber will advise
you weather to stop your medication.