CSD skin test

Alternative names:

cat scratch disease skin test

How the test is performed:

The antigen is injected just under the skin, usually on the forearm, so that a small lump pushes the skin up. The lump indicates that the antigen has been injected at the correct depth. The site is labeled, usually with an ink pen.

After 48 to 72 hours, the skin should appear red or irritated where the antigen was injected. The size and degree of irritation will determine whether the antigen is present in your or your child's system.

How to prepare for the test:

There is no special preparation. People with dermatitis or other skin irritations may have the test performed at different locations on the body.

How the test will feel:

When the antigen is injected, there is a slight stinging sensation where the needle is inserted. After the reaction begins, the area will probably itch or burn.

Why the test is performed:

This test is very helpful in determining if you or your child has cat scratch disease. If the disease is present in your system, then the antigens that are unique to that disease are also present. If there are antigens, and you have a healthy immune system, then your body has a way of responding to that antigen. Therefore, if cat scratch disease antigen is injected under the skin and you have the disease, your body will have an immune response and there will be an area of inflammation at the site of the injection.