The skin prick is usually done on the inside of your forearm. But if you have eczema or another skin problem, the doctor or nurse may want to do the test on your back.
The doctor or nurse will choose different allergens (something that may cause an allergic reaction). Up to 25 allergens can be used.
The doctor or nurse will mark your arm using a waterproof pen so that he or she can easily identify the allergen. Then the doctor will place a drop of each allergen next to the marks on your arm.
You will be given a small scratch to your skin through the middle of each drop.
If you are allergic to any of the allergens your skin will become very itchy and you may get raised bumps (like nettle stings).
How long will it take?
It takes around 20 minutes for the reaction to take place. You will see the doctor or nurse again before you go home.
Does it hurt?
It will probably be a bit uncomfortable but it shouldn’t hurt you.
The doctor or nurse will be able to tell you the results before you go home.Last reviewed by Great Ormond Street Hospital: 22 January 2006