Intradermal Test
Pronunciation: in-truh-DER-mul test
An allergy skin test in which a small volume of allergen is injected directly into the dermis to detect immediate or delayed hypersensitivity reactions.
Full Definition
An intradermal test (IDT) involves injecting 0.02–0.05 mL of a diluted allergen solution intradermally to create a small bleb, then measuring the resulting wheal-and-flare response after 15–20 minutes for immediate reactions, or reading at 48–72 hours for delayed-type hypersensitivity. It is more sensitive but less specific than a prick test, and is used in drug allergy evaluation and venom hypersensitivity assessment. Editors encountering this term in allergy-dermatology documentation should distinguish it from the patch test (epicutaneous, for contact sensitisation) and the prick test (superficial skin puncture). The term is sometimes erroneously hyphenated as 'intra-dermal'; standard medical usage does not hyphenate the prefix.
Usage
Usage note: Do not hyphenate as 'intra-dermal'. Distinguish from patch test (epicutaneous, delayed contact allergy) and prick test (immediate IgE-mediated, superficial). Each has a distinct methodology and clinical application.
In Context
- "The allergy report documented positive intradermal test results to penicillin at a dilution of 1:1000." — Allergy assessment report
- "Do not use 'intra-dermal test'; the unhyphenated 'intradermal test' is the accepted medical form." — Style convention note