Both corns and calluses are thickening of the skin that develops due to chronic external weight-bearing pressure and from skeletal pressure within the foot.

A corn is a conical lesion that forms within the skin of the foot. It has a hard lesion with a core. The base of the lesion is round and small in size. The texture is rough and thick. Corns develop in the skin from repeated forceful weight-bearing pressure on a small area of bony prominence usually at the distal aspect of toes and between toes from the friction of the bones of each toe.

A callus can be a diffuse lesion of the skin that is more spread out or it also can have a central core. It is also formed from repeated weight-bearing pressure but over a greater area on the foot and in some case intractable due to pressure of a boney prominence.

Both corns and calluses can be painful while walking and wearing shoes. At-home treatments should be avoided as this may potentially lead to an infection. The foot and ankle surgeon will evaluate the lesion and assess for the underlying cause with purpose to prevent the lesion from recurring as readily or at all.

Palliative treatment may involve paring the lesions and involve orthotics that incorporate offloading of weight-bearing pressures. Permanent resolution of corns and calluses may require surgery to remove bony prominences and correct bone and joint deformities such as hammertoes that cause pressure to the ball of the foot and top of the toes or metatarsals that are in low position causing pressure on forefoot.