A plantar callus is a hard, thickened area of skin that develops on one or both feet. Plantar calluses, like all calluses, form in response to pressure or friction to protect the skin underneath from damage.
Calluses develop in areas of friction, typically on the hands or feet. A plantar callus forms on the bottom of the foot and usually results from wearing shoes that are overly tight or otherwise ill-fitting.
In this article, we look into what plantar calluses are, what causes them, and how to remove them. We also describe the difference between a plantar callus and a plantar wart.
A callus refers to a patch of hardness on the outer layer of the skin. When friction applies repeated pressure to the skin, calluses develop.
Hyperkeratosis is the medical name for this thickening. The body uses hyperkeratosis to protect the skin from repeated rubbing, pressure, or irritation.
A plantar callus forms on the sole of the foot. These calluses tend to develop near the base of the toes, due to friction from the foot rubbing against the inside of the shoe.
Problems with walking or with the feet can cause calluses when these issues place added stress on certain parts of the foot.
Calluses are not typically painful. However, corns, a similar foot issue, can be painful when pressed.
Calluses may become discolored after some time — a brown, black, or red patch may form beneath the hardened skin. This happens when a small amount of blood pools between the thickened skin and the regular skin underneath.
Plantar calluses usually form when ill-fitting or tight shoes rub against the soles of the feet. As the friction continues, a hard layer of outer skin develops to protect the skin beneath.
In some cases, the way a person walks can cause this hardening of the skin, possibly because of a foot or toe deformity or a recent operation.
Most calluses gradually go away when the friction stops. Some people consider them unsightly and would rather remove them than wait for them to fade.
The American Academy of Dermatology offers the following tips for treating calluses:
- Soak the area in warm water for about 5–10 minutes or until the skin softens.
- Dip a pumice stone in warm water, then gently file the callus to remove the dead skin. Circular or sideways motions work best.
- Be careful to only remove a small amount of skin. Taking too much off could make the callus bleed and lead to infection.
- Moisturizing daily with a lotion or cream that contains salicylic acid, ammonium lactate, or urea will help gradually soften hard calluses.
- To keep calluses from getting worse, try padding. Cut a piece of callus padding into two half-moon shapes and place them around the callus.
Bandages, pads, and other products that contain salicylic acid can also help reduce or get rid of calluses.
It is important to note that anyone with a disorder affecting the nerves or circulation in the feet should be careful when using products, such as bandages, on their feet.
A person can usually find the products mentioned above at a local pharmacy, as well as online:
It is a good idea to speak to a doctor if a callus is large, painful, or getting in the way of daily activities. The doctor may shave off some of the hardened skin and recommend modified footwear to prevent the callus from reforming.
If a callus bleeds or breaks, it is important to keep it clean and covered while it heals. Applying petroleum jelly, such as plain Vaseline, to the area and covering it with a Band-Aid works well. This will help prevent infection and promote healing.
The best way to prevent plantar calluses is to wear shoes that fit well. Low-heeled, comfortable shoes that have enough space around the toes are a good choice.
Wearing socks can also help reduce friction and decrease the likelihood of calluses developing.
People sometimes mistake plantar calluses for a type of wart that forms on the feet, known as a plantar wart.
A wart is a skin infection caused by the human papillomavirus. When a wart develops on a foot, it is called a plantar wart. People often contract the infection by walking barefoot.
Plantar warts tend to be hard and flat. They usually have well defined borders and a rough surface. These warts are typically skin colored with tiny black dots. While doctors once believed that these dots represent clotted blood vessels, research indicates that they may represent tiny collections of blood within the top layer of the skin, called the epidermis.
Another difference between plantar warts and calluses is that warts may be painful, while calluses typically are not.
People can use over-the-counter preparations of salicylic acid to treat warts. These are also available for purchase online. If symptoms worsen or do not resolve over time, speak with a dermatologist about other treatment options.
The American Podiatric Medical Association recommend that anyone with a suspicious growth on a foot receive a diagnosis from a podiatrist.
Calluses on the feet tend to come back after being removed, but they are usually no cause for concern. A podiatrist can suggest further treatment options.