Plantar warts are common skin growths that develop on the soles of the feet, including the toes, heels, or balls of the feet. This article explores the origins of plantar warts, from their viral cause to their pathways of infection and early symptoms.
The Viral Cause
Plantar warts are caused by specific types of the human papillomavirus (HPV). Certain HPV strains, including types 1, 2, 4, 27, 57, 60, and 63, are responsible for these foot growths. These strains differ from those causing warts elsewhere or more serious conditions. The virus stimulates an overgrowth of skin cells, leading to wart formation.
Pathways of Infection
The HPV virus typically enters the skin through tiny cuts, abrasions, or weak spots on the bottom of the foot. A break in the skin is generally necessary for infection to take hold. Once the virus enters, it can take several weeks to months for a visible wart to develop.
The virus thrives in warm, moist environments, making public areas like communal showers, swimming pools, and locker rooms common sites for transmission. Walking barefoot in these places increases exposure. The virus can spread through direct contact with contaminated surfaces or skin-to-skin contact. Sharing items such as shoes, socks, or towels with an infected individual can also facilitate transmission.
While HPV strains causing plantar warts are not highly contagious person-to-person, the virus can spread from one area of an individual’s foot to another. A weakened immune system can also increase susceptibility. Children and teenagers are more prone to developing plantar warts, partly due to increased exposure in public spaces and their developing immune systems.
Recognizing Early Signs
Initially, a plantar wart may appear as a small, rough growth on the sole of the foot. These growths often have a grainy texture and can be flesh-colored or slightly discolored, sometimes appearing yellowish, brown, or gray.
A distinguishing feature of plantar warts is the presence of tiny black dots, often referred to as “wart seeds.” These specks are small clotted blood vessels within the wart. Plantar warts frequently develop on weight-bearing areas of the foot, such as the balls, heels, or under the toes.
Due to pressure from walking and standing, plantar warts can grow inward, causing a layer of hard, thickened skin (a callus) to form over them. This inward growth can lead to pain or tenderness when pressure is applied. The sensation may feel like a small pebble in the shoe. Pain can make walking or standing uncomfortable, potentially altering one’s gait.