Induration after Mantoux test in children below 4 year of age is considered positive if - - RUHS, Jaipur, PB B.Sc Nursing Entrance-2023

RUHS, Jaipur, PB B.Sc Nursing Entrance-2023

Child Health Nursing (Pediatrics)

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2023

Explanation

For children younger than 4 years old, an induration of 10 mm or greater is considered a positive Mantoux test result.
This lower threshold is used because young children have a higher risk of progressing from latent TB infection to severe, disseminated disease.
The immune system of young children is less mature, making them more vulnerable to rapid disease progression after exposure to Mycobacterium tuberculosis.
This criterion applies even in the absence of other specific risk factors, purely based on the age group.

Option B: An induration of more than 5 mm is considered positive, but only for the highest-risk groups, not as a general rule for all children under 4.
Option C: An induration of more than 15 mm is the threshold for low-risk individuals, which does not apply to young children.
Option D: An induration of 2 mm is not a recognized clinical threshold for a positive Mantoux test and would be considered a negative result.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Interpretation of Mantoux test results in pediatric patients as background academic context rather than a clinical decision trigger.
Nurses must accurately measure the induration of a Mantoux test, not the erythema, to ensure correct interpretation and avoid false-positive readings. The reading should be done 48-72 hours after placement.
Patient education is a key nursing role. The nurse should instruct the parent/guardian on when to return for the reading and to not scratch or cover the test site.
A positive test does not necessarily mean active disease; it indicates exposure to TB bacteria. Further evaluation, like a chest X-ray and clinical assessment, is required to diagnose active TB disease.

How to Approach the Question

First, identify the key patient demographic in the question: 'children below 4 year of age'.
Next, recall the specific diagnostic criteria for this group. The question is about the 'Mantoux test' and asks what size of 'induration' is 'positive'.
Access your knowledge of TB testing guidelines. Remember that the criteria for a positive test are stratified by risk.
Recognize that being under 4 years old is in itself a risk factor for disseminated disease, which places these children in a specific category.
Compare the options to the standard guidelines. The threshold for children <4 years is ≥10 mm. The threshold for high-risk individuals is ≥5 mm, and for low-risk individuals ≥4 years is ≥15 mm.
Select the option that matches the guideline for the patient group described in the question.

Concept Tested & Keywords

Concept Tested: Interpretation of Mantoux test results in pediatric patients
Stem keywords: Mantoux test, induration, children below 4 year, positive
Lead-in keywords: considered positive if
Clinical cues: Patient age (below 4 years) is the critical factor for determining the correct induration threshold.

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