What is a key characteristic of nail psoriasis?

Nail psoriasis is characterized by the presence of tiny pits or roughness on the surface of the nails. This symptom is a result of the rapid turnover of skin cells, which leads to the formation of small depressions known as pitting. These pits can vary in size and depth and often appear randomly across the nail surface, disrupting the normally smooth appearance of healthy nails.

While other nail conditions can involve folding, grooves, or discoloration, these features do not specifically define nail psoriasis. The unique presence of pits is a key indicator that helps in diagnosing the condition, making it the most distinctive characteristic among the options presented.