Hyperkeratosis, better known as callus or corn, are the skin’s natural defence mechanism against friction or excessive pressure. Ultimately, they cause a thickening and hardening of the skin. Calluses are mainly found on the soles of the feet, the inner edge of the big toe or on the edges of the heels. This thickening of the skin may not initially cause any issues, but calluses can become problematic. Corns have a deeper core and are usually painful, sometimes unbearably so. People describe it as walking on a rock, or as if a needle is piercing their skin when they stand. Calluses, which remain untreated, can crack and produce unpleasant complications.

Corns and calluses have many causes. Wearing poorly fitting shoes, obesity, biomechanical abnormalities when walking, loss of fatty tissue under the foot and bone protuberances are typical examples. Although rare, certain systemic or hereditary diseases can also be the cause.