Yaws is a tropical spirochetosis characterized by damage to the skin, bones and joints, internal organs are not affected. Etiology. The causative agent is Treponema pertenue, the Spirochaetaceae family. Epidemiology. The disease is recorded in all tropical regions, especially in Equatorial Africa, South America, southern Asia and the islands of Oceania. The main route of transmission is contact (very rarely – sexual) through damaged skin. The most susceptible are children and adolescents, especially those suffering from eczema and dermatitis.

Clinical picture

    • The incubation period is 2-4 weeks.
    • Primary stage: the formation of rashes on the skin (frambeziomas), accompanied by fever, headaches and joint pain, regional lymphadenitis and lymphangiitis.
    • The secondary stage develops in 1-3 months. The appearance of numerous polymorphic rashes bordered by zones of hyperemia (frambezida) is characteristic. After a few weeks, part of the papules disappears, and part transforms into gum-like nodes up to 1 cm, which undergo decay. In 20% of cases, periostitis is observed, in others, confluent lesions within the mouth or anus. The duration of the second stage is 3-6 months in babies and 6-12 months in adults.
    • Lichenoid frambeside – multiple small dense lichenoid papules
    • Lupoid frambezide – small soft confluent papules that disintegrate to form rough scarring ulcers
    • Papular frambeside – a pink papule with a central depression, gradually covered with verrucous growths that look like raspberries
    • Pigmented frambeside – pigment spots of irregular shape, covered with silvery-white bran-like scales
    • Spotted frambeside – pink edematous spots up to 1 cm in diameter, transforming into papules or leaving areas of skin atrophy.
    • In the absence of adequate treatment, the tertiary stage develops, characterized by the formation of ulcerative-gumous bone lesions and severe destructive disorders that simulate tertiary syphilis. However, they are quite small and do not contain the pathogen. Among bone changes, nasal exostoses (gundu) are observed, more often recorded in children in the form of tumor-like growths, deforming nasopharyngitis (gangosis) and progressive ulcerative-granulomatous destruction of the hard palate.

Research methods are similar to those for syphilis. In 80-100% of patients, a positive von Wassermann reaction is noted, as well as other reactions to syphilis. Unlike Treponema pallidum, Treponema pertenue disappears from peripheral lymph nodes immediately after yaws have healed. The causative agent is found in exudate, regional lymph nodes, biopsy material of lesions. Treponema pertenue is found in fresh papules in 80-100% of cases. The bacterioscopic method does not allow to distinguish the pathogen from pale treponema. The diagnosis is established by the clinical picture. Differential Diagnosis

    • Syphilis
    • Tuberculosis
    • Leprosy.

Treatment – see Syphilis.

The prognosis of the disease is favorable, although in some patients the process is delayed up to 30 years. After the illness, a strong immunity develops.


  • Pian
  • Gangoza
  • Yaws tropical
  • Rupee
  • Tropical granuloma
  • Syphilis non-venereal
  • Tropical syphilis ICD A66 Yaws

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