Skin test anergy
Key points
- In a skin test anergy, a common antigen such as Mumps, candida, or trichophytin is injected just under the skin.
- An antigen is injected just under the skin, usually on the forearm, so that a small lump pushes the skin up.
- People with dermatitis or other skin irritations may have the test performed at different locations on the body.
- When the antigen is injected, there is a slight stinging sensation where the needle is inserted.
Alternative names
Anergy screen or panel
Definition
In a skin test anergy, a common antigen such as Mumps, candida, or trichophytin is injected just under the skin. The purpose is to determine if a patient's immune system is reacting properly to antigens in general.
An anergy test is usually just a control for some other skin test that is being performed. Because the anergy test can show whether your immune system is functioning properly or not, it can indicate whether the results of the other skin test are reliable.
How the test is performed
An 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, if the immune system reacts to the antigen, the skin will appear red or irritated where the antigen was injected. The size and degree of irritation will determine whether you are responding to the antigen. A second visit after 48 to 72 hours 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
There is no special preparation. People with dermatitis or other skin irritations may have the test performed at different locations on the body.
In infants and children:
The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:
- 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)
- School age 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 may itch or burn. Sometimes a strong reaction can turn into a large, red, irritated area.
Written and revised by
Gerald Hurowitz, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.