Yaws is a bacterial infection that causes lumps and sores on the skin of the hands, face, feet, and groin. It is common in tropical areas of the world and usually affects children younger than age 15.

Yaws is caused when the bacteria treponema pertenue enter a cut or scrape in the skin and form a sore. The glands around the sore swell but are not usually painful. Other symptoms include loss of appetite, weakness, and tiredness. If it is not treated the infection will spread, cause skin sores, and destroy bones and joints.

Yaws is diagnosed with a blood test. The bacteria that causes yaws is similar to the bacteria that causes syphilis, so someone who has yaws may test positive for syphilis. Yaws is not a sexually transmitted infection (STI). It is spread by skin-to-skin contact.

Yaws is treated and easily cured with antibiotics.