Intradermal
In or into the skin.
An intradermal injection is given into the skin.
Intradermal tests are a type of skin test.
An agent (such as pollen) is injected into the skin to test the reaction to it.
Intradermal tests are much used to diagnose allergy and to test cellular immunity.
The most superficial application of a substance would be epicutaneous (on the skin); then would come intradermal (in the skin); next subcutaneous (just under the skin); then intramuscular (into the body of the muscle), etc.