What can cause Beau's lines to appear on nails?

• A. Excessive nail care
• B. Trauma or illness
• C. Constant moisture
• D. Exposure to chemicals

Answer: (B)

Beau's lines are transverse grooves or indentations that form across the nail plate and typically indicate a temporary interruption in nail growth. The appearance of these lines is primarily associated with physical trauma or systemic illness. When the body undergoes stress due to an illness (like a severe infection or a major surgery) or experiences trauma (such as an injury to the nail matrix), the growth of the nail is affected, leading to the formation of these noticeable lines. This phenomenon occurs because the growth cycle of the nail is disrupted, and as the nail continues to grow post-recovery, it displays these lines reflecting the periods of compromised growth.

Other factors such as extensive nail care, constant moisture, or chemical exposure, while they may affect nail health and appearance, do not specifically trigger the formation of Beau's lines in the same manner that trauma or significant illness does. Such conditions may lead to other types of nail disorders but are not directly linked to the development of these distinctive transverse lines. Thus, trauma or illness is the most accurate and relevant cause of Beau's lines.