Warts are caused by an infection of the skin with the human papilloma virus (HPV). They can occur on any part of the body, but are commonly seen on the hands or feet. The virus can be transmitted from one site on the body to another and from person to person by direct and indirect contact.
Common warts are generally benign growths, but can cause problems when they become irritated, painful, or cosmetically unfavorable. Local irritation of the wart and cosmetics are the most common reasons individuals will have them removed.
Warts on the hands can be flat (flat warts) or raised lesions. Often, small black dots can be seen on the surface of a raised wart. These dots are erroneously referred to by many as “seeds,” implying that the wart is transmitted by these dots. In fact, these black dots are small blood vessels or capillaries within the growth and have nothing to do with transmission of infection.
Warts on the soles of the feet are called plantar warts. They are so called because they occur on the “plantar surface” of the foot. These warts tend to be flat and more difficult to detect and treat because of the thick callous of the skin. Oftentimes they will become painful due to the direct pressure of walking on the lesions.
Some individuals never get warts and others seem to be plagued with them throughout their lifetime. This may be due to each individual’s natural immunity to the virus. There is reason to believe that those who get recurrences of warts may harbor the virus within their skin. Treatment may remove the visible wart, but the virus lays dormant deep in the underlying skin tissues.
From study, we know that 50 percent of warts will go away by themselves. However, it may take years for this to occur and it is impossible to predict which warts will spontaneously resolve and which will not. Treatment for common warts can often be frustrating. The goal of treatment is to remove the cells that are infected with the virus. This can be accomplished through the use of chemicals, heat and cold.
Over-the-counter topical wart preparations contain chemicals, such as salicylates (aspirin-based), which kill the virus-containing cells. Products include liquid applications (Compound W) or bandages containing the chemical which are applied over the wart. They can be effective, but slow, if used religiously each day as directed.
Freezing or burning the wart also kills the infected cells, thus eliminating the growth. Liquid nitrogen is used in the doctor’s office for freezing warts. Some over-the-counter devices are now available for freezing, but in my experience I have not found these to be cold enough to be highly effective against common warts. Liquid nitrogen, however, is near minus 300ºF.
Other methods your doctor may use to treat warts include topical prescription medicines or direct injection of the wart with medicines to cause the body to fight off the wart. Usually as a last resort the wart can be burned or cut off. This, however, can lead to scarring and pain as a result of the scar. Generally, it’s best to consult with your physician to see which treatment will be right for you.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.