Yaws

1. Adult Skin Problems Slideshow Pictures
2. Take the Skin Conditions Quiz
3. Gallery of Skin Problems Pictures

Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

View Full Profile

Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

Yaws is a common chronic infectious disease that occurs mainly in warm humid regions such as the tropical areas of Africa, Asia, South and Central Americas, plus the Pacific Islands. The disease has many names (for example, pian, parangi, paru, frambesia tropica). Yaws usually features lesions that appear as bumps on the skin of the face, hands, feet, and genital area. The disease most often starts as a single lesion that becomes slightly elevated, develops a crust that is shed, leaving a base that resembles the texture of a raspberry or strawberry. This primary lesion is termed the mother yaw (also termed buba, buba madre, or primary frambesioma). Secondary lesions, termed daughter yaws, develop in about six to 16 weeks after the primary lesion. Almost all cases of yaws begin in children under 15 years of age, with the peak incidence in 6-10-year-old children. The incidence is about the same in males and females.

Yaws is caused by a particular bacterium called a spirochete (a spiral-shaped type of bacteria). The bacterium is scientifically referred to as Treponema pertenue. This organism is considered by some investigators to be a subspecies of T. pallidum, the organism that causes syphilis (a systemic sexually-transmitted disease). Other investigators consider it to be a closely related but separate species of Treponema. T. carateum, the cause of pinta (a skin infection with bluish-black spots), is also closely related to T. pertenue. The history of yaws is unclear; the first possible mention of the disease is considered to be in the Old Testament. D. Bruce and D. Nabarro discovered the spirochete causing yaws (T. pertenue) in 1905.