Hand warts are a skin condition that can spread easily, sometimes occurring during everyday activities like shaking hands or sharing pool towels.

These warts are the result of an infection from the human papillomavirus (HPV). The U.S. Food & Drug Administration states that there are over 100 strains of HPV. Each strain affects different body areas, and not all of them lead to the formation of warts.

When the skin is exposed to a wart-inducing strain of HPV, it triggers an excess production of skin cells. This process leads to the development of thick, hard growths on the skin’s surface, as noted by WebMD.

What causes warts on hands?

Common warts, known as verruca vulgaris, frequently show up on hands, according to Dr. Ronda Farah, MD, FAAD, a dermatologist at M Health Fairview and the University of Minnesota Medical School. These warts typically appear as rough, skin-colored bumps, and can also feature small black dots resembling seeds. The primary culprits are HPV strains 2 and 4, but other strains including 1, 3, 7, 27, 29, and 57 have also been implicated, according to Cleveland Clinic.

Flat warts may also appear on the hands, described as “skin-colored bumps that disrupt the skin’s texture,” and are generally found on the “tops of the hands,” according to Dr. Farah. Unlike most warts, flat warts have a smooth texture and can occur in clusters ranging from 20 to 200. They are connected to HPV strains 3, 10, 28, and 49, as reported by Healthline.

Periungual warts, which emerge around the nails of fingers and toes, result from HPV strains 1, 2, 4, 5, 7, 27, and 57, according to WebMD. Butcher’s warts tend to develop in individuals who frequently handle raw meat or fish, caused by HPV strain 7, according to Cleveland Clinic.

Are warts on hands contagious?

“All warts are contagious,” Dr. Farah explains. They can spread by touching surfaces that a person with warts has touched. Warts can also be transmitted through direct skin contact and can transfer from one part of the body to another, according to Mount Sinai.

Despite being contagious, warts are usually harmless and painless. Dr. Farah emphasizes, “Warts are generally not cancerous; they are benign.” In rare cases, some might develop verrucous carcinoma, a form of skin cancer. If you notice that a wart grows quickly, doesn’t respond to treatment, or causes pain, a board-certified dermatologist can conduct a biopsy, she advises.

Are common warts on hands an STD?

Dr. Farah states that common hand warts are not classified as a sexually transmitted disease (STD). It’s crucial to note that the strains responsible for genital warts differ from those causing common warts, she adds.

Mayo Clinic notes that over 40 HPV types can affect the genital area. The strains responsible for genital warts are almost exclusively transmitted through sexual activities. HPV is one of the most prevalent sexually transmitted infections in the United States, and it’s estimated that over 14 million Americans are newly infected each year, according to Cleveland Clinic.