A keratoma is a hard, light-colored patch of skin that develops as a result of friction or pressure. Also called a callus, a keratoma is most likely to appear on the soles of the feet, the backs of the heels, or the palms of the hands. Wearing uncomfortable shoes or working without gloves can lead to blistering and eventually to keratomas. In most cases, calluses are painless and not a cause for concern. Many different home remedies and medical products are available to help people remove calluses and learn how to prevent future skin problems.
The outermost layer of skin is largely made up of cells called keratinocytes which contain hard material that protects against heat and light. Keratinocytes have a short life-cycle and they are constantly being shed. When an area of skin is subjected to repetitive rubbing or pressure, hard keratinocytes build up in an effort to better protect underlying layers. The result is a rough, raised, firm callus.
A keratoma on the bottom of the foot can appear if a person starts running or walking more than usual, wears ill-fitting shoes, or has an abnormal gait that results in uneven weight distribution. Calluses on the heels are usually caused by loose shoes that slip up and down when walking. Construction workers, golfers, tennis players, and other people who perform repetitive activities with their hands may develop keratomas on their fingers or palms. Calluses are usually small, about 0.5 inches (about 1.25 centimeters) in diameter, though they can be two or three times larger.
Pain, swelling, or tenderness around a callus is unusual, and a person should visit a doctor if such symptoms arise to check for infections or other types of more serious skin conditions. In most cases, calluses are slightly lighter-colored than surrounding skin and feel rough to the touch. They may become dry, scaly, and flaky over time. If a callus does not hurt or look abnormal, it is usually unnecessary to seek medical care.
Soaking keratomas in warm water can soften the skin and help them clear up in a few weeks. A person can also use a washcloth or a pumice stone to rub off the outermost layer of flaky skin and promote faster healing. Using lotion and wearing comfortable shoes or gloves is important during the healing phase to prevent further irritation to the skin. In addition, a person may want to consider buying protective pads or shoe inserts at a pharmacy to make sure calluses do not return. If calluses persist, a doctor can prescribe a salicylic acid solution or consider surgically removing especially thick patches.