Plantar warts

DEFINITION

Plantar warts are hard, grainy growths that usually appear on the heels or balls of your feet, areas that feel the most pressure. This pressure also may cause plantar warts to grow inward beneath a hard, thick layer of skin (callus).

Plantar warts are caused by the human papillomavirus (HPV). The virus enters your body through tiny cuts, breaks or other weak spots on the bottom of your feet.

Most plantar warts aren’t a serious health concern and may not require treatment. But plantar warts can cause discomfort or pain. If self-care treatments for plantar warts don’t work, you may want to see your doctor to have them removed.

CAUSES

Plantar warts are caused by an infection with the human papillomavirus (HPV) in the outer layer of skin on the soles of your feet.

More than 100 types of HPV exist, but only a few cause warts on your feet. Other types of HPV are more likely to cause warts on other areas of your skin or on mucous membranes.

Transmission of the virus

Each person’s immune system responds differently to HPV. Not everyone who comes in contact with it develops warts. Even people in the same family react to the virus differently.

The HPV strains that cause plantar warts aren’t highly contagious. So the virus isn’t easily transmitted by direct contact from one person to another. But it thrives in warm, moist environments. Consequently, you may contract the virus by walking barefoot around swimming pools or locker rooms. If the virus spreads from the first site of infection, more warts may appear.

The virus also needs to have a point of entry into the skin of the foot:

• Cracks in dry skin
• Cuts or scrapes
• Wet, softened, fragile skin from being in the water a long time

SYMPTOMS

Plantar wart signs and symptoms include:

• A small, fleshy, rough, grainy growth (lesion) on the bottom of your foot
• Hard, thickened skin (callus) over a well-defined “spot” on the skin, where a wart has grown inward
• Black pinpoints, which are commonly called wart seeds but are actually small, clotted blood vessels
• A lesion that interrupts the normal lines and ridges in the skin of your foot
• Pain or tenderness when walking or standing

When to see a doctor

See your doctor for the lesion on your foot if:

• The lesion is painful or changes in appearance or color
• You’ve tried treating the wart, but it persists, multiplies or recurs
• Your discomfort interferes with activities
• You also have diabetes or poor sensation in your feet — in which case, you’ll need treatment supervised by a doctor
• You also have a weakened immune system because of immune-suppressing drugs, HIV/AIDS or other immune system disorders
• You aren’t sure whether the lesion is a wart