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Clinical Characteristics

The differing distribution of the primary and secondary lesions is probably the result of climatic and social differences. Where the climate is hot and moist, young children are usually naked and any part of the skin may be the site of the initial infection. Where the climate is hot and dry, the primary lesions will only occur where there is moisture, particularly around the mouth and anus and in the flexures. (The spirochetal disease most common in temperate climates, venereal syphilis, shows its primary site where there is direct contact between moist epithelial surfaces, i.e., on the genitalia and lips in the majority of patients.)

Early and Late Yaws and Endemic Syphilis

The staging of treponemal infections is almost as confusing as the classification of the causal spirochetes. There is no easy way to describe exact stages as the disease progresses, because there is often no distinct interval or change by which the stages can be separated. For this reason, yaws is sometimes divided into "early yaws" and "late yaws." Early yaws applies to infections which have lasted less than 5 years; late yaws includes the sequelae after that stage. Within these two broad divisions, the infection progresses through the more classical primary, secondary and tertiary stages.

Primary Stage

The incubation period is usually 3-7 weeks, with a range from 10 to 90 days. In all of the nonvenereal forms of treponematoses, the primary lesion may be overlooked as it is so often located in a nongenital area. In addition, there is some variation related to the inoculated dose of treponemes; the larger the inoculation, the more obvious the primary lesion. The initial lesions may occur in any exposed part of the skin. In yaws, the first lesions are moist papillomas, usually discrete and seen most frequently below the knee. The first lesion is the mother yaw, and there is often regional lymphadenopathy. It starts as a small papule, but reaches up to 5 cm in diameter, becomes lifted, is often ulcerated, and may resemble a raspberry (hence "framboiseioma"). Systemic reaction is uncommon, but rarely there may be fever and arthralgia. The secondary lesions can appear before the mother yaw has healed. The palms of the hands and the soles of the feet often become hyperkeratotic, with painful fissures. When this happens the patients can only walk on the sides of their feet, using a characteristic "crab" gait.

In endemic syphilis, primary ulcerating lesions can also occur on the breasts of nonimmune mothers, but most primary lesions are small papillomas, frequently in the mouth or nasopharynx and often unrecognized. Condyloma may also be the primary lesion.

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Copyright: Palmer and Reeder