Which one of the following is a intradermal test?

RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Fundamental of Nursing

Easy

Appeared in: RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Explanation

The Mantoux (MT) test is a screening tool for tuberculosis that involves an intradermal injection.
The procedure requires injecting 0.1 mL of Purified Protein Derivative (PPD) into the dermis of the forearm, creating a wheal.
An intradermal test is defined by the injection of a substance into the dermal layer of the skin, which is precisely what the MT test entails.
The result is based on a delayed-type hypersensitivity reaction, which manifests as a palpable induration at the injection site.

Option B: The Allen test is a physical assessment of blood circulation in the hand and does not involve any injection.
Option C: The Tourniquet test assesses capillary fragility by applying pressure with a cuff, not by injection.
Option D: This option is incorrect because the Allen test and Tourniquet test are not intradermal procedures.

Visual 1: Diagram - Showing the correct angle and depth of an intradermal injection, highlighting the formation of a wheal in the dermis.
Visual 2: Photograph - A close-up of a positive Mantoux test result, clearly showing the measured induration on a forearm.
Visual 3: Infographic - Step-by-step illustration of how to perform the Allen test, showing compression of radial and ulnar arteries and subsequent hand flushing.
Visual 4: Photograph - The arm of a patient after a positive Tourniquet test, displaying petechiae below the cuff line.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identification of Intradermal Diagnostic Tests as background academic context rather than a clinical decision trigger.
Accurate administration of the Mantoux test is a fundamental nursing skill. An incorrect technique (e.g., subcutaneous injection) can lead to a false-negative result, potentially delaying diagnosis and treatment for TB.
Patient education is crucial for a valid test result. Nurses must clearly instruct patients to avoid irritating the site and to return at the correct time (48-72 hours) for the reading.
Distinguishing between induration and erythema is a common point of error. Nurses must be trained to palpate and measure only the hardened area for an accurate interpretation.

How to Approach the Question

First, identify the key term in the question: 'intradermal test'. This means you are looking for a procedure where a substance is injected into the dermis (the layer of skin just below the epidermis).
Next, review each option and recall or deduce its purpose and procedure.
Consider 'MT test'. Recall that this is the Mantoux test for TB, which involves a PPD skin injection. This fits the definition of an intradermal test.
Consider 'Allen Test'. Recall this is a manual test for blood circulation in the hand, involving pressure, not injection.
Consider 'Tourniquet test'. Recall this uses a blood pressure cuff to check for capillary fragility, involving pressure, not injection.
Based on this analysis, only the MT test is an intradermal procedure, making it the correct answer.

Concept Tested & Keywords

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