The vaccine that leaves a permanent scar in babies is?

AIIMS Raipur - 2017 (Shift-3)

Child Health Nursing (Pediatrics)

Easy

Appeared in: AIIMS Raipur - 2017 (Shift-3)

Explanation

The Bacille Calmette-Guérin (BCG) vaccine is specifically designed to be administered intradermally (into the top layer of the skin).
This route of administration triggers a specific local inflammatory reaction, which is a key part of the immune response.
The reaction progresses from a papule to an ulcer over several weeks, and its healing results in the formation of a characteristic permanent scar.
This scar is considered a normal outcome and a sign of successful vaccination against tuberculosis.
The image provided shows a typical BCG scar on the upper arm, confirming this visual characteristic.

Option A: The Measles vaccine is administered subcutaneously (under the skin) and does not cause a permanent scar as a normal reaction. Local reactions are typically mild and transient.
Option B: The Pentavalent vaccine is given as a deep intramuscular injection, usually in the thigh. While it can cause temporary local soreness, redness, or swelling, it does not result in a permanent scar.
Option C: Similar to the Pentavalent vaccine, the DPT vaccine is administered intramuscularly. It does not produce the type of localized, prolonged skin reaction that leads to a permanent scar.

Visual 1: Image - A clear photograph showing the typical appearance of a healed BCG scar on the upper arm, as seen in the question's image.
Visual 2: Diagram - A step-by-step illustration showing the evolution of the BCG vaccination site over 12 weeks, from the initial papule, to the ulcer, and finally the healed scar.
Visual 3: Chart - The National Immunization Schedule (India) for infants, highlighting the BCG vaccine's timing (at birth), route (intradermal), and site (left upper arm).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identification of the vaccine that causes a permanent scar as a normal reaction as background academic context rather than a clinical decision trigger.
The presence of a BCG scar is a quick and reliable visual cue for healthcare workers, especially in community settings, to verify a child's vaccination status against tuberculosis without needing to check records.
Nurses are responsible for educating parents about the normal progression of the BCG reaction, reassuring them that the papule and ulcer formation are expected and not signs of infection, and advising them not to apply any medication to the site.
What if? If a baby does not develop a scar after BCG vaccination, it does not automatically mean the vaccine was ineffective. The World Health Organization (WHO) does not recommend revaccination based on the absence of a scar alone, as immunity can still develop.

How to Approach the Question

First, analyze the question's core requirement, which is to identify a vaccine that leaves a 'permanent scar'.
Review the options provided: Measles, Pentavalent, DPT, and BCG.
Recall the standard administration routes and expected local reactions for each vaccine. Differentiate between intramuscular, subcutaneous, and intradermal routes.
Recognize that the intradermal route used for BCG is unique among these options and is specifically associated with a characteristic scar-forming reaction.
Examine the provided image, which shows a classic BCG scar, to visually confirm the expected outcome.
Conclude that BCG is the only vaccine among the choices that consistently and normally leaves a permanent scar.

Concept Tested & Keywords

Concept Tested: Identification of the vaccine that causes a permanent scar as a normal reaction.
Stem keywords: vaccine, permanent scar, babies
Lead-in keywords: is
Negative lead-in flag: false

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