Some central nail elevations may appear as vertical nail lines around the nail, possibly because the longitudinal shape of the nail changes as a result of the nail elevation, resulting in a longitudinal nail ridge. It is often seen in brittle nails, brown nails, nail malnutrition due to vitamin or calcium malabsorption, frequent exposure to acids, alkalis, organic solvents or detergents, nail art, etc.
In the presence of disease factors such as lichen planus, chronic eczema and impaired peripheral circulation, a central nail elevation with a longitudinal nail ridge may also be seen.