Skip to Main Content

For further information, see CMDT Part 34-05: Yaws (Frambesia)

Key Features

  • A contagious disease largely limited to tropical regions that is caused by Treponema pallidum subspecies pertenue

  • Acquired by direct nonsexual contact, usually in childhood, although it may occur at any age

Clinical Findings

  • Characterized by granulomatous lesions of the skin, mucous membranes, and bone

  • The "mother yaw," a painless papule that later ulcerates, appears 3–4 weeks after exposure

  • Regional lymphadenopathy is usually present

  • Secondary lesions that are raised papillomas and papules

    • Appear 6–12 weeks later

    • Weep highly infectious material

    • Last for several months or years

  • Painful ulcerated lesions on the soles are called "crab yaws" because of the resulting gait

  • Late gummatous lesions may occur, with associated tissue destruction involving large areas of skin and subcutaneous tissues

  • Late effects of yaws may be confused with similar changes occurring in leprosy and include

    • Bone change

    • Shortening of digits

    • Contractures

  • Central nervous system, cardiac, or other visceral involvement is rare


  • Organisms can be demonstrated in infectious lesions with darkfield microscopy or immunofluorescence but cannot be cultured in artificial media

  • Serologic tests for syphilis are positive


  • If untreated, may lead to chronic disability and disfigurement

  • Penicillin, 2.4 million units of benzathine penicillin G intramuscularly is generally curative in any stage of the non–sexually transmitted treponematoses

  • In cases of penicillin hypersensitivity, tetracycline, 500 mg orally four times a day for 10–14 days, is the recommended alternative

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.