Yaws is a chronic infectious disease caused by the spirochete Treponema pallidum subspecies pertenue.
Yaws has a global distribution in tropical regions. Once very common, it has much succumbed to eradication campaigns. It remains active in remote areas of poor tropical nations.
Yaws is transmitted via open sores, non-venerealy, from person to person.
The initial lesion is the "mother yaw", an erythematous papule at the site of primary infection that ulcerates and, with a yellow crust and exudate, extends peripherally. Vegetations may occur. There may be an associated adenopathy. The initial lesions heal with scarring in 2 to 6 months.
The second stage, appearing by 4 months, is the development of crops of "daughter yaws"; papules that crust, ulcerate, and form exophytic growths resembling raspberries. Less commonly, there can be a generalized eruption of lenticular, hypomelanotic macules and papules. There can be systemic symptoms that include fever, malaise, and bone pain. The tertiary or late stage affects skin, bones and cartilage. Ulcerating gummas can appear on the extremities. Debilitating keratoderma of the palms and soles can occur. Ostitis can cause severe bone deformity. Synovium is commonly involved, resulting in severe dysfunction. Gangosa is a mutilation of the central face resulting from the destruction of cartilage and bones.
- Benzathine penicillin 2.4 million units in a single dose is usually curative.
- Alternative antibiotics are tetracycline and erythromycin.
- All contacts are commonly treated with penicillin.