What are warts?

Warts are contagious viral skin tumours. They are usually benign. In persons with impaired immunity, warts may become malignant. Warts are a very common dermatological complaint, affecting 75% of people during their lives. Most people get warts, but they are more common in children and young adults.

Risk factors

Young people are most at risk; as one gets older, the immune system becomes better prepared for the viruses. Skin trauma can worsen infection and cause spreading through self-infection (auto-inoculation). The viruses are spread by direct contact, so avoiding physical contact with other people’s warts may be a good idea.

Warts are contagious and may be transmitted via contact. You can reinfect yourself by shaving around infected areas.

The human papilloma virus (HPV) family, of which more than 80 types are known, causes this skin infection. Some types may cause the common wart, which can appear on the skin of the hands, feet and nail beds.

Other types are found around the genitals (genital warts). They can also cause papillomas on the vocal cords. Some HPV subtypes are involved in the development of malignancy.

To diagnose warts, the doctor will obtain a history and do an examination. In most cases there won’t be any need for further tests. In older people, the doctor might excise the lesion for examination by a pathologist to confirm the diagnosis and exclude more serious conditions.

Course

Warts, if left untreated, will develop in various ways. Most common warts will grow slowly. Eventually growth reverses spontaneously and the warts disappear within two years. If they are treated, they will disappear sooner. Some warts can be quite persistent and usually continue to grow, and even undergo malignant change, depending on the type of HPV involved.

It is said that, in children, 80% lose their warts spontaneously in nine months.

Reviewed by Prof H.F. Jordaan, MBChB, MMed (Derm).