Corn.

Corns and calluses are areas of skin that have been thickened because of constant pressure. The difference between corns and calluses is that corns are small and arise on the toes, while calluses are bigger and generally develop on the soles of the feet.
Structure
A corn looks like a hardened yellowish mass, and mayor may not be painful, but there is always a danger that it may become a problem at a later stage.
Causes
Everybody at some or other point of time may face these problems. These develop as a sequel to wearing ill-fitting or worn-out shoes or hard & firm slippers. These cause patches of thickened, hardened skin at the various points where shoes exert friction or pressure on the skin surface.
Herbal Medicines
Since these are hardened masses, a gentle application of castor oil or coconut oil on these spots regularly 3 to 4 times a day makes them soft.
Turmeric powder well mixed in honey or neem oil should be applied on these corns.
Temporary use of an insole or a replaceable pad to wear inside a shoe-to relieve excess pressure on the foot is essential.
The milky juice of papaya fruit is applied to remove corns.
Ayurvedic Remedies
Kasisadi Taila is a readymade preparation. It is to be applied on the corns for a few days until the corns become soft and ultimately fall out.