Yaws

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

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