<Tr> <Td_colspan="2"> Examples of callus found on the toe </Td> </Tr> <Tr> <Th> Specialty </Th> <Td> Dermatology </Td> </Tr> <P> A callus is an area of thickened skin in response to repeated friction, pressure, or other irritation . Rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form . Since repeated contact is required, calluses are most often found on feet because of frequent walking and incorrectly fitting footwear . Calluses are generally not harmful, but may sometimes lead to other problems, such as an skin ulceration or infection or cause the sufferer to try and offload the effected painful area, which can place excessive stress on the asymptomatic side . </P> <P> Normally, a callus will form on any part of the skin exposed to friction over a long period of time . For example, people often develop calluses on the middle finger of their dominant hand due to writing with a pen or pencil . Another cause is from playing string instruments like the guitar or the violin; calluses will develop on the four fingers of the hand used in holding the strings down to the fingerboard, and sometimes on the fingers of the hand used for pizzicato or strumming . Weightlifters commonly experience callus on the upper - palm area due to repeated friction . </P>

Where do calluses on your feet come from