What is a wart?

Dr. Marc-André Doré

Tuesday, August 16, 2022

A wart is a non-cancerous growth caused by a subset of strains of the human papillomavirus (HPV.) Though unrelated to the HPV strains involved in genital infections, the wart-causing strains can be equally tenacious. Because they target the outermost layers of the skin, simple surface contact with wart-causing strains can lead to infection even if the skin is otherwise undamaged.

Quick note!

Human Papillomavirus (HPV)

A few specific strains of HPV are associated with cervical cancer and, to a lesser extent, cancers of the vulva, vagina, penis and anus. These particular strains of HPV can also cause condyloma (genital warts). However, the strains of HPV that cause vulvar (plantar or palm) warts are not associated with cancer.

The answer is yes.

Are warts contagious?

Warts of all kinds are very contagious and plantar warts are no exception. Of course, direct contact between a wart and a skin lesion is one way to transmit the virus, but it is not the only way.

  1. The virus survives for several days without a host, which means it can be transmitted indirectly. For example, if an infected person walks barefoot on a floor, the virus can survive on the floor and infect another person who walks barefoot on the floor several days later.

  2. A person can spread the virus to themselves by touching the plantar wart and then touching other parts of their body. This is called self-inoculation of the virus.

Note that several months or even years may pass between the infection and the appearance of the plantar wart itself.

How do warts look like?

Plantar warts often appear on the soles of the feet, while palmer warts usually appear on the fingers or top surface of the hands. Despite this distinction, non-STD warts can appear anywhere on the body, and there's no clinical difference between the virus strains responsible for plantar, palmer, and other non-STD wart infections. 

Once the virus enters the skin it establishes a colony just beneath the surface. This colony will remain isolated and highly localized throughout most of the infection's lifespan, though some warts may reach deeper than others. In response to this infection, nearby skin cells multiply rapidly, leading to a small growth that is heavily packed with the virus. This is a reaction to the irritation of the infection and an attempt by the body to isolate the viral colony by surrounding it with a wall of skin cells.

Palmer warts usually present as a small flesh colored nodule, while plantar warts are typically forced into a flatter, deeper plaque beneath the skin due to the pressure of walking.

A typical infection will last several months up to several years, though it may continue even longer in people with weak immune systems. As the immune system gradually develops an effective defense against the virus the warts will subside. However, like many viruses, the HPV colony will attempt to shield itself and enter a dormant state. It may even send out secondary colonies to lie dormant in deeper parts of the skin. These dormant colonies can lead to additional outbreaks in the future, though most immune systems will have developed antibodies that are effective enough to quell this cycle.

Can warts be treated?

Because wart infections are generally self-resolving, most medical professionals only recommend treatment in the case of severe irritation or pain.

Surgical treatments will attempt to remove the wart and any surrounding skin tissues, ideally removing the entire viral colony before it has a chance to establish any secondary or dormant infections. Over-the-counter products use a weak acid solution or a freezing mechanism in an attempt to kill the infected skin cells and encourage the body to slough them off.

It is very likely that even the most effective treatments will leave some remnant of the viral colony behind. Because of this and the tendency of the virus to go dormant, ultimate pacification will always depend on the immune system learning to mount an effective defense against the infection.

Dermago can help

When to consult a doctor?

  • When the wart is painful

  • When there is bleeding or signs of infection

  • When the wart has an abnormal or asymmetric shape

  • When plantar warts are chronic

Woman using a phone to consult a dermatologist

Looking to learn more?

These are some articles that may interest you