Which type of nail disorder can result from repetitive trauma or pressure?

• A. Nail ridges
• B. Beau's lines
• C. Onychomycosis
• D. Ingrown nails

Answer: (B)

Beau's lines are transverse lines that run across the nail plate and can indeed be a result of trauma or physiological events that temporarily inhibit nail growth, such as severe stress, illness, or injury to the nail matrix. When there is repetitive trauma or pressure applied to the nail, it can disrupt the normal growth pattern, leading to noticeable indentations or grooves in the nails, which are classified as Beau's lines.

On the other hand, nail ridges can occur for several reasons, including aging or certain health conditions, but they do not specifically arise from repetitive trauma. Onychomycosis, which refers to nail fungus, typically results from fungal infections rather than mechanical damage. Ingrown nails occur when the nail grows into the surrounding skin, usually causing pain and potentially infection, rather than directly resulting from repeated trauma to the nail itself.

Thus, Beau's lines are the correct answer as they are directly tied to interruptions in nail growth due to repetitive physical impacts or stress on the nail.