The Mantoux test is carried out by:

Appeared in: DSSSB October 2024

Explanation

The Mantoux test requires a precise volume of 0.1 ml of Purified Protein Derivative (PPD) solution.
The correct route of administration is intradermal, which means injecting the solution just under the top layer of skin to form a wheal.
The standard injection site is the flexor (inner) surface of the forearm, which is ideal for accessibility and accurate reading.
This combination of volume, route, and site is essential for the test's validity and to elicit a readable delayed-type hypersensitivity reaction.

Option A: This option is incorrect because the volume (1 ml) is ten times the standard dose, and the injection site (extensor surface) is not the preferred location.
Option B: This option is incorrect due to both the excessive volume (1 ml) and the incorrect route of administration (subcutaneous). A subcutaneous injection would lead to a false-negative result.
Option D: This option uses the correct volume (0.1 ml) but specifies the wrong route (subcutaneous) and the wrong site (extensor surface). A subcutaneous injection invalidates the test.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Procedure for Mantoux Test Administration as background academic context rather than a clinical decision trigger.
Correct administration of the Mantoux test is a fundamental nursing skill critical for accurate tuberculosis screening programs.
An incorrect technique, such as a subcutaneous injection, can lead to a false-negative result, potentially delaying diagnosis and treatment for an individual with TB infection and allowing for continued transmission in the community.
Patient education is vital. The nurse must instruct the patient not to scratch or rub the site and to return within 48-72 hours for the reading, explaining that failure to do so will require a repeat test.

How to Approach the Question

First, identify the core components of the question. The question asks for the correct procedure for the Mantoux test.
Break down the procedure into four key variables mentioned in the options: dose (1 TU), volume (ml), route (intradermal/subcutaneous), and site (flexor/extensor forearm).
Recall or look up the standard protocol for the Mantoux test. The key facts are: 0.1 ml volume, intradermal route, and flexor surface of the forearm.
Systematically evaluate each option against these three criteria.
Option A fails on volume (1 ml) and site (extensor).
Option B fails on volume (1 ml) and route (subcutaneous).

Concept Tested & Keywords

Qy5w5VIQe6GrQaLNXlJax_

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart B (pp 202-403 of 604) p. 25-27

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 257-259

E6 Medicine Harrison 22e Part 1 p. 1442-1444

Practise the full DSSSB October 2024

Attempt every question from this paper in a timed mock, then review the full solution for each one.