Which of the following is a contraindication for using CHG?

• A. During hand washing.
• B. For skin preparation in reconstruction of the external ear.
• C. For cleaning surgical instruments.
• D. For preoperative patient skin cleansing.

Answer: (B)

The use of chlorhexidine gluconate (CHG) has specific contraindications due to its properties and potential effects on certain tissues. In the context of skin preparation for surgery, particularly involving sensitive areas such as the external ear, there is a risk of irritation or allergic reactions. CHG can be harsh on delicate skin, making it unsuitable for procedures that may affect aesthetically and functionally sensitive regions, such as reconstructive surgeries involving the ear.

In contrast, the other options listed are generally accepted uses of CHG. It is effective during hand washing to reduce microbial counts, can be employed for cleaning surgical instruments when used correctly, and is often the preferred agent for preoperative skin cleansing due to its broad-spectrum antimicrobial activity. However, healthcare providers must evaluate the specific requirements and sensitivities based on the area being treated, highlighting the importance of contraindications like those associated with the external ear.