Calluses under the feet are common sources of pain and frustration There is often a misconception about these can be treated, as many people assume they can simply be cut out. This article will discuss what actually can be done to provide treatment, and dispel some of the myths surrounding their treatment.
Calluses on the bottom of the foot are from a natural process that is designed to protect the foot skin from excessive pressure. This excessive pressure can come from several sources. Externally, pressure can come from simply walking or standing on the ground, whether one is in shoes or not. The shoe itself can even be a source of external pressure, although this is usually seen resulting in corns on the top of the toes (which is the same type of condition as a callus). Internally, pressure can come from the bones that lie beneath the skin. If the bones are abnormally prominent due to a foot structure abnormality (like a bunion or flat feet), or if the skin and padding below the bone is abnormally thin, then pressure will increase on the overlying skin. The skin is usually irritated by both internal and external sources of pressure at the same time, where external pressure from walking combined with internal pressure from prominent bones or thin skin create a reaction in the skin tissue. This reaction causes the skin to form a thickening of the outer layer of keratin-based cells, which squish together to form multiple layers.
Over time, a callus (also called a hyperkeratosis) develops as the skin becomes excessively thick at the spot of pressure. This callus, if thick enough, can be painful as the original normal skin layer on the bottom of the callus is harmed by the pressure of the layer that covers it. What once was a simple protective measure by the skin can turn into a source of pain and damage for the skin if growth progresses far enough. Sometimes, the callus grows inward towards the base layer of the skin, leading to the formation of a thick, hard core that tunnels inward (but does not break the skin). This is also called an intractable plantar keratosis, and is often mistaken for a wart. Finally, sweat and other skin glands can fill with keratin material, forming a small pinpoint callus called a porokeratosis. This type of callus does not need to have a prominent bone underneath it for it to form, and is usually not painful.
Callus treatment is often misunderstood, and in reality can be somewhat complicated. The most common form of treatment is simple shaving of the callus by oneself, a pedicurist, or a podiatrist. The act of thinning the hard skin will make it more comfortable to walk on, and will reduce pain. However, the cause of the callus still will exist, and the callus will eventually return in a month or two. This causes great confusion for some people, who simply associate a callus with a temporary skin growth, and not something directly tied to their foot structure and activity. The use of special shoe padding or foot supports to reduce the pressure on the bottom of the foot can help to limit the growth of a callus, when used in combination with callus shaving and properly fitting shoes. Unfortunately, these will not eliminate the callus permanently, and will only serve to help reduce the overall thickness of the callus when it regrows. Even prescription shoe inserts (orthotics) will not permanently reduce calluses, although they do de-weight the callused area better than store-bought inserts by being custom made to a mold of the foot.
It should be noted that diabetics should never attempt to manage their calluses on their own. Due to poor sensation from diabetes, diabetics trimming their own calluses or having an unskilled family member try this at home could lead to a wound and an infection from an accidental cutting into normal skin.
Some people assume a callus can be burned off, like a wart or other skin growth. The use of chemicals, lasers, cold treatment, and electricity to destroy skin growths is very common, and often effective for other types of skin disorders. Unfortunately, these techniques do not work as well on callus tissue, because the growth of the callus is continuous, and not based on the simple presence of abnormal skin cells that can be removed. Callus tissue is normal tissue, and any destructive procedure against this tissue will only temporarily be successful until skin growth begins anew, and the callus reforms. The only exception to this is a porokeratosis, which can be removed if the underlying gland and gland duct is destroyed.
Surgical treatment is the next level of callus care. This is another area where there is great confusion, and treatment myths abound. In short, calluses cannot be cut out or otherwise surgically removed, with the expectation that the callus will not return. The new skin that grows following the surgery will continue to form a callus, and when combined with a surgical scar may be even more painful than the original callus. The only exception once again is the porokeratosis, which can be successfully removed with surgery. The only way to permanently get rid of a callus is to get rid of the underlying bone prominence, and to ensure shoes fit properly and are properly padded to account for any skin and tissue thinning over these bones. There are a multitude of bones in the foot that can cause enough of a prominence to irritate the skin, and as many ways to resolve the pressure through bone surgery. Procedures can include lifting of bones that steep too far towards the bottom of the foot, removal of extra bones that naturally form during development (very common), shaving or removal of bone spurs or loose bone fragments, or even full removal of the part of the bone causing the pressure. Procedures to correct the overall deformity causing the pressure, such as a bunion, or arch abnormality, may be needed. Healing times will vary, and is dependent on whether the bone was simply shaved or extracted, or whether the bone position was moved. These procedures are generally successful in eliminating callus formation if done properly, although there is a risk for the pressure point of the foot to simply move over to the next bone. Orthotics are often used following surgery to prevent this from occurring.
As one can see, callus care is not simply about shaving or cutting out the hard tissue. In reality, this myth does not work out well, and bone surgery is necessary to keep callus care from becoming an exercise in regular skin maintenance through regular shaving and shoe inserts. This may provide complete relief for some. For others, surgery is needed to break the ongoing pain cycle.