A chronic infection caused by bacteria that affects the skin, bones and joints.

Yaws is an infection caused by Treponema pallidum, subspecies pertenue bacteria. The bacteria are in the same group of germs as syphilis-causing bacteria. But syphilis spreads by sexual contact and yaws spreads by general skin contact. Yaws-causing bacteria live in areas of the world that are hot and humid. They most often spread among children.

The first symptom of yaws is a solid-looking bump where the infection starts. More bumps that look like warts may appear later. Some people have swollen lymph nodes near the site of the infection. Without treatment, the infection can damage skin, bones, joints and in some cases the nervous system.

Yaws is treated with antibacterial medicine.