Mantoux & TB Skin Test in Delhi | Accurate TB Diagnosis

Mantoux Test

The Mantoux test is a simple skin test used to check whether a person has been exposed to the bacteria Mycobacterium tuberculosis the germ that causes tuberculosis (TB). It does not confirm active TB but shows whether your immune system has reacted to TB bacteria in the past.

Why It Is Done?

To detect the latent TB infection (when TB bacteria are in the body but not causing symptoms).
To support diagnosis in active TB cases along with other tests.
For TB screening in:
Healthcare workers.
People living in TB-endemic areas.
Close contacts of TB patients.
People with weak immunity (e.g., HIV).
Before starting certain medications (like steroids or biologics).

Symptoms

Persistent cough for more than 2 weeks.
Unexplained fever or night sweats.
Unintentional weight loss.
TB exposure history.
Screening before travel to TB-prone countries.

How to Prepare for the test?

No fasting or any other special preparation is required.
Inform the doctor if you:
Have had BCG vaccination (can affect results).
Have had TB before.
Have a weak immune system.
Are pregnant.
Avoid applying creams or lotions on the forearm before the test.

How It Is Done?

A small amount (0.1 ml) of purified protein derivative (PPD) is injected just under the skin of your forearm.
This creates a small, pale bump (wheal) at the injection site.
You have to return to the clinic 48–72 hours later to check for reaction.
The doctor measures the induration (raised, hard area), not redness.

What It Measures

The test measures your immune system’s reaction to TB proteins:

A positive result means you have TB infection at some point.
A negative result means no TB infection or very weak immune response.

Interpretation of Results (Induration size & risk factors)

≥5 mm: Positive in high-risk groups (HIV, recent TB contact, immunosuppressed)
≥10 mm: Positive in moderate-risk groups (diabetes, healthcare workers, and immigrants from TB-endemic countries)
≥15 mm: Positive in healthy individuals without known TB risk

Frequently Asked Questions (FAQs)

1. Is the Mantoux test painful?

Only a small prick is felt, and the discomfort is minimal.

2. Can I get the site wet?

Yes, but avoid scratching or pressing hard on it.

3. What if I miss the 48–72 hour reading?

The result becomes unreliable, the test may need to be repeated.

4. Does a positive test mean I have TB?

No, not always, it means that TB bacteria are in your body but other tests like chest X-ray, sputum tests are needed to confirm active TB.