Skin test anergy

Alternative names:

anergy screen

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 you are allergic to the antigen. A second visit is required to have the results confirmed. You may be given washing instructions so that the test will be accurate.

How to prepare for the test:

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

Infants and children:
The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:

• infant test or procedure preparation (birth to 1 year)
• toddler test or procedure preparation (1 to 3 years)
• preschooler test or procedure preparation (3 to 6 years)
• schoolage test or procedure preparation (6 to 12 years)
• adolescent test or procedure preparation (12 to 18 years)

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 a person's immune system is functioning properly. A skin test can indicate no exposure to a particular antigen, when actually the immune system is unable to react to any antigen.