Which term describes the condition where the nail becomes smaller, opaque, and ridged due to injury or disease?

The correct term for the condition where the nail becomes smaller, opaque, and ridged due to injury or disease is onychatrophia. This term specifically refers to the wasting away or atrophy of the nail, which can result from various factors including trauma, infections, or systemic diseases. The visible changes such as size reduction, opacity, and the development of ridges reflect the degradation of the nail structure.

Onychocryptosis refers to ingrown nails, which are a different condition involving the nail growing into the surrounding skin. Tinea unguium, another term, describes a fungal infection of the nails, which often leads to discoloration and thickening but does not specifically indicate the shrinking and ridging of the nail itself. Paronychia is an infection of the skin around the nail, leading to redness, swelling, and often pus formation, but it doesn't define the structural changes in the nail as seen in onychatrophia. Understanding these distinctions is essential for accurately diagnosing nail conditions in beauty therapy.