Identification of BCG Scar

BCG Scar Variability Based on Age and Skin Type

The Bacillus Calmette–Guérin (BCG) vaccine is administered to protect against tuberculosis. A characteristic scar usually forms at the site of injection, though its appearance can vary significantly based on factors such as age and skin type.

Characteristics of a BCG Scar

• Typically forms within 2-6 months post-vaccination.
• Varies in size from 4mm to 10mm.
• Most often appears on the upper left arm.

Variability Based on Age

In neonates and infants, the scar is generally more defined due to their developing immune response. In contrast, older individuals may exhibit either a larger or faded scar.

Variability Based on Skin Type

Individuals with darker skin tones may develop more pronounced pigmentation around the scar, whereas those with lighter skin tones may have a more subtle scarring effect.

Clinical Importance

The presence of a BCG scar is often used in epidemiological surveys to confirm vaccination history. Lack of scarring, however, does not necessarily indicate vaccine failure.

Conclusion

While the BCG vaccine scar is a helpful marker, its variability should be acknowledged in clinical assessments.