Process of Skin Testing

Our preferred location for skin testing is the skin on the back, which gives the best results. Normally we will ask you to lie on your tummy for the skin testing part of your appointment. This will take around 60 minutes.

Skin pricks and intradermal injections are placed into the skin and marked in pen. Anywhere from 5-20 injections may be required. Each injection site is then marked again at 15-20 minutes to see if a change has occurred.

If a test is positive, a small hive or welt will form at the injection site and there may be redness (flare) around the site. 

Positive tests may become itchy. Itching normally lasts 5-10 minutes, although occasionally a test site remains itchy for longer. While being tested, you cannot scratch the sites because it may make the test impossible to interpret.

One substance used will be a positive control which will cause your skin to react. This is to demonstrate what a positive result should look like on your skin.

If being tested for a delayed reaction (a reaction that developed hours to days after exposure) then we may ask you to observe and photograph any changes over a period of days.