What is Yaws?

Yaws is a tropical infection of the bones, skin, and joints caused by the spirochete bacterium Treponema pallidum pertenue and is a common disease of children in the tropics.  Yaws is a chronic relapsing infectious disease and is transmitted by skin-to-skin contact and usually enters through a scrape or a cut in the skin.

Yaws has three stages: early yaws, second-stage yaws, and late yaws.  As of 2012 Yaws is common in at least fourteen tropical countries including areas of Africa, Asia, the Pacific Islands, and Latin America.  About 75% of those affected are children under the age of 15.  The condition affects both men and women and no race is exempt.  The spread of the disease is facilitated by poor sanitation and poor personal hygiene.

Cases of the condition have increased and the goal is to globally eradicate Yaws by the year 2020.  The disease was first described by Willem Piso in 1679 but archaeological evidence suggests that the disease was present in the human population as far back as 1.6 millions years ago.  A blood test may be ordered to check for evidence of infection with the bacteria that cause yaws.  Without treatment around 10% of individuals will develop disabling and disfiguring complications within five years because the disease destroys skin and bones.

What are the Symptoms of Yaws ?

Yaws is characterized by a rash that forms a brown crust, swollen lymph nodes (swollen glands), bone and joint pain, painful sores or bumps on the skin and on the soles of the feet, and a single itchy raspberry-like growth (mother yaw) on the skin that usually appears on the buttocks or legs.

Yaws Causes

Yaws is a chronic tropical infection that primarily affects the bone, skin, and cartilage of children in the African, Asian, and Latin American areas of the world. The bacteria that causes the condition is called spirochete bacterium.

Yaws is a rare disease in the United States, occurring fewer than 1,000 times per year. It occurs much more frequently in areas where there are fewer treatment options available and where there are larger numbers of those affected by the disease coming into contact with one another.

Yaws is only rarely fatal. Instead, after the condition has run its course, the lesions harden over and leave a scar. Yaws occurs in 14 countries that are considered tropical.

How is Yaws Treated?

Treatment consists of a single shot of penicillin but those allergic to penicillin may be treated with azithromycin, doxycycline, or tetracycline.

Yaws Prevention

Yaws manifests itself primarily by ulcers that appear on the surface of the skin. These ulcers often discharge fluid from the lesion. As a result, those who are infected are most often the same people who have come into contact with these lesions. This contact is not necessarily sexual. Children are primarily affected since they most often come into contact with each other closely while playing.

Prevention of yaws is most often done by curing entire villages at a time, since close contact is the primary means of transmission. Fortunately, the lesions that appear make it obvious who is affected by the condition. As a result, it is easy to treat those affected, usually through the use of antibiotics.

Without treatment, physical deformities occur in 10% of cases. These treatments are usually highly effective. As a result, the WHO considers Yaws to be controlled, although a recent increase in cases has caused the organization to renew its efforts at fighting the condition. Their hope is to eradicate Yaws by 2020.

Last Reviewed:
October 09, 2016
Last Updated:
September 08, 2017