intradermal test

skin test

a method for determining induced sensitivity (allergy) by applying an antigen (allergen) to, or inoculating it into, the skin; induced sensitivity (allergy) to the specific antigen is indicated by an inflammatory reaction of one of two general kinds: 1) immediate, appears in minutes and is dependent on circulating immunoglobulins (antibodies); 2) delayed, appears in 12-48 hours and is not dependent on these soluble substances but on cellular response and infiltration.

Synonym(s): cutaneous test, intradermal test, skin reaction

intradermal test

n.

A test for hypersensitivity or allergy in which a small amount of the suspected allergen is injected into the skin.

intradermal test

Etymology: L, intra + Gk, derma, skin

a procedure used to identify suspected allergens by subcutaneously injecting the patient with small amounts of extracts of the suspected allergens. The injections are made at spaced intervals, usually in the forearm or the scapular region. The patient is concurrently injected with the diluent alone as a control procedure. The test result is positive if within 15 to 30 minutes the injection of extract produces a wheal surrounded by erythema and the control injection produces no symptoms. The intradermal test is started with highly diluted solutions; if the initial test result is negative, the procedure is repeated with stronger solutions. This gradual method is used to prevent a systemic reaction, which is more of a risk with intradermal testing than with other kinds of allergy testing, such as the scratch test. The intradermal test tends to be more accurate than the scratch test and is often performed if scratch test results are negative or unclear. Intradermal testing also limits to between 20 and 30 the number of suspected allergens that can be examined simultaneously in the skin of one patient. Also called subcutaneous test. Compare patch test, scratch test. See also conjunctival test, use test.

skin test

(skin test)

A method for determining induced sensitivity (allergy) by applying an antigen (allergen) to, or inoculating it into, the skin; induced sensitivity (allergy) to the specific antigen is indicated by an inflammatory reaction of one of two general kinds: 1) immediate, appears in minutes to an hour or so and in general is dependent on circulating immunoglobulins (antibodies); 2) delayed, appears in 12-48 hours and is not dependent on these soluble substances but on cellular response and infiltration.
Synonym(s): intradermal test.

skin test

(skin test)

A method for determining induced sensitivity (allergy) by applying an antigen (allergen) to, or inoculating it into, the skin; induced sensitivity (allergy) to the specific antigen is indicated by an inflammatory reaction.
Synonym(s): intradermal test.

intradermal

within the dermis.

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intradermal test

see skin test.

single intradermal test

a test used in the field diagnosis of bovine tuberculosis. A small volume of tuberculin is injected intradermally, commonly in a tail fold, and observed at 72 to 96 hours for a significant increase in thickness of the skin. The tuberculin elicits a cell-mediated immune reaction at the site of injection in infected animals and the increased thickness of the skin is the consequence of infiltration into the site of T lymphocytes and activated macrophages.