Sharp spicules of the lateral nail margin are gradually driven into the dermis of the nail groove. The nail acts as a foreign body, introducing typical skin flora into the break in the skin. An inflammatory response develops in the area of penetration, leading to erythema, edema, purulence, and granulation tissue. Lateral margins of the great toe are most frequently affected. No mortality is associated with ingrown nails.
Morbidity is chiefly the result of infection of the tissues.
No racial bias appears to exist. The condition is seen in all ages but is most common in the second decade of life. All ages are seen. It becomes much more common as children begin bearing weight on their feet and wearing shoes. Ingrown nail presents as sharp focal pain at the lateral end of the toe that worsens with weight bearing and ambulation.