Organism: Treponemia pallidum subspecies pertenue
Distribution: western Africa, Indonesia, New Guinea and Pacific Islands
There are 3 stages of the disease: primary, secondary and tertiary/late
The initial infection typically occurs during childhood through skin-to-skin contact.
The primary lesion is referred to as the "mother yaw" and is a localized papilloma or ulcer up to 5 cm in diameter. The primary lesion is most often seen on a lower extremity.
Secondary skin lesions may be polymorphous, with papulosquamous lesions that usually heal spontaneously within 3-6 months.
Late lesions may involve skin and bone and can be destructive.
(1) osteoperiostitis of long bones with bone deformation
(2) dactylitis
(3) gummas
(4) possible cardiovascular disease
There can be serologic cross-reactivity with syphilis.
