| ICD9 = | }} Yaws also Pétasse tropica, thymosis, polypapilloma tropicum, pian or parangi) (also known as "Bouba," "Frambesia," and "Pian")'s a tropical infection of the skin, bones and joints caused by the spirochete bacterium Treponema pallidum pertenue. Other treponemal diseases are bejel (Treponema pallidum endemicum), pinta (Treponema pallidum carateum), and syphilis (Treponema pallidum pallidum). History Examination of ancient remains has led to the suggestion that yaws has affected… (More on Yaws)