A callus is a thicken layer of skin that can appear anywhere on the body. They are most common on the hands and feet due to the repeated pressure these areas are put under. A callus is a protective action and its purpose is to protect the skin from damage. Calluses are not harmful, but can cause other skin problems such as ulceration or infection. So how are calluses formed? Read this article to find out.
What causes calluses?
Calluses are caused by repeated rubbing or friction on the skin. They are most commonly found on the hands and feet due to the friction applied by shoes, hand tools or other instruments. Long term friction must be applied for a callus to be formed. Too much friction over a short period of time causes blisters rather than calluses. It is common for most people to have a callus on the middle finger of their dominant hand caused by the repeated use of a pen or pencil. Stringed instruments are also a common cause of calluses with a musician’s four fingers developing calluses on the pads from depressing the strings. Many sports and labour intensive jobs also cause calluses on the fingers and hands. Calluses on the feet are sometimes referred to as corns and are often caused by the friction of a shoe rubbing against the skin. People may also develop calluses on their knees if they spend a lot of time kneeling on abrasive surfaces such as concrete or carpet. Teachers and child care workers commonly develop calluses on their knees.
To form a callus the body accumulates dead keratinocytes in the outermost layer of the skin. These keratinocytes are resistant to mechanical and chemical wear due to the high levels of proteins and keratin (the substance that nails are made from). Certain toxins, such as arsenic, can also cause calluses to develop. Syphilis, a sexual transmitted disease, can cause the skin on the palms and soles of the feet to thicken and become hard.
The most common way to prevent the formation of calluses is to prevent prolonged rubbing on the skin. Buy the correct size and shape of shoe, wear gloves and avoid use of friction causing tools and instruments.