Corns generally occur at pressure points, typically the bottom of the feet and the sides of toes. They can be painful.
A hard corn is a small patch of thickened, dead skin with a central core. A soft corn has a much thinner surface and usually occurs between the 4th and 5th toes. A seed corn is a tiny, discrete callous that can be very tender if it’s on a weight-bearing part of the foot. Seed corns tend to occur on the bottom of the feet, and some doctors believe this condition is caused by plugged sweat ducts.
Calluses are thickenings of the outermost layer of the skin and are painless. They can develop on hands, feet, or anywhere there is repeated friction — even on a violinist’s chin. Like corns, calluses have several variants. The common callus usually occurs when there’s been a lot of rubbing against the hands or feet. A plantar callus is found on the bottom of the foot.
Some corns and calluses on the feet develop from an improper walking motion, but most are caused by ill-fitting shoes. High-heeled shoes are the worst offenders. They put pressure on the toes and make women four times as likely as men to have foot problems. Other risk factors for developing a corn or callus include foot deformities and wearing shoes or sandals without socks, which leads to friction on the feet.
Rubbing or pressure can cause either soft corns or plantar calluses. If you or your child develops a callus that has no clear source of pressure, have it looked at by a doctor since it could be a wart or caused by a foreign body, like a splinter, trapped under the skin. Feet spend most of their time in a closed, moist environment — ideal for breeding bacteria. Staph infections can start when bacteria enter corns through breaks in the skin and cause the infected corn to release fluid or pus.
Originally Published By WebMD.com