The induration of skin between 6 and 9 mm after tuberculin test indicates?

DSSSB - 28 August 2019 (Shift-1)

Community Health Nursing

Easy

Appeared in: DSSSB - 28 August 2019 (Shift-1)

Explanation

An induration of 6 to 9 mm following a tuberculin skin test is classified as a 'doubtful' or 'equivocal' reaction.
This result is indeterminate and does not definitively confirm or exclude a tuberculosis infection.
The reaction could be due to an infection with Mycobacterium tuberculosis or a cross-reaction with non-tuberculous mycobacteria.
Individuals with a doubtful result may require further evaluation, such as a repeat test or an Interferon-Gamma Release Assay (IGRA), especially if they have risk factors for TB.

Option B: This is incorrect. An induration of less than 5 mm is typically considered negative, indicating no risk or no infection.
Option C: This is a risk factor, not an interpretation of the test result itself. The test result is the measurement of the induration.
Option D: This is incorrect. A 'positive' result is generally defined as an induration of 10 mm or more in the general population.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Interpretation of Tuberculin Skin Test (Mantoux Test) results as background academic context rather than a clinical decision trigger.
A key nursing responsibility is to accurately read the TST at 48-72 hours and correctly interpret the result based on both the induration size and the patient's specific risk factors.
A doubtful result requires careful consideration. The nurse should document the finding and ensure the patient is scheduled for follow-up as per facility protocol, which may include re-testing or an IGRA blood test.
Patient education is crucial. The nurse must explain that a doubtful result is not a diagnosis of TB but requires further investigation.

How to Approach the Question

First, identify the core of the question: it's asking for the interpretation of a specific measurement from a tuberculin test.
Recall the standard classification for Mantoux test results based on the diameter of induration.
The key values to remember are the cutoffs: less than 5 mm (negative), 5 mm or more (positive for high-risk groups), 10 mm or more (positive for general population), and the range in between.
The question specifies an induration between 6 and 9 mm. This falls into the intermediate category.
Evaluate the options provided. 'Doubtful for tuberculosis' directly corresponds to the standard interpretation for a 6-9 mm induration.
Eliminate other options: 'No risk' is for smaller indurations, 'Tuberculosis positive' is for larger indurations, and 'Contact with active TB patients' is a risk factor, not a test result interpretation.

Concept Tested & Keywords

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