History and Physical Examination
Yaws has 3 clinical stages: primary, secondary, and tertiary. Stages are interspersed with asymptomatic latent periods. The typical yaws patient is young and from an endemic area and has been exposed to infected persons with active disease. [13, 14] Primary lesions, also called mother yaw, develop at the site of inoculation. (See the images below depicting yaws lesions).
Initial papilloma, also called mother yaw or primary frambesioma (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
Plantar papillomata with hyperkeratotic macular plantar early yaws (ie, crab yaws) (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta.Geneva, Switzerland: World Health Organization; 1984.).
Osteoperiostitis of the tibia and fibula in early yaws (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
Early yaws papillomata (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
Early ulceropapillomatous yaws on the leg (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
Squamous macular palmar yaws (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
Primary stage
Early yaws lesions include the following:
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Papilloma
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Serpiginous papilloma
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Ulceropapillomata
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Squamous macules
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Maculopapules
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Nodules
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Plaques
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Hyperkeratosis of palms and soles
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Bone and joint lesions
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Generalized lymphadenopathy (may occur)
The initial yaws lesion is a papule that enlarges to become a papilloma or frambesioma. The yaws papilloma resolves spontaneously after 3-6 months. Bone and joint involvement may occur in early disease and may cause pain and swelling. Lymphadenopathy, fever, and joint pain may accompany this stage.
After an incubation period of 9-90 days (with an average of 3 weeks), the primary lesion, or the mother yaw, develops at the site of inoculation after a scratch, bite, or abrasion of exposed skin, most commonly on the legs, feet, or buttocks. The primary lesion is a reddish, nontender, and, occasionally, pruritic papulonodule.
The mother yaw ulcer develops a honey-brown crust and enlarges horizontally to 1-5 cm in diameter, sometimes coalescing with satellite lesions. The crust frequently sloughs and reveals a raspberrylike base. On rare occasions, a primary lesion is not seen. Because the exudate of the raspberrylike ulcer is teeming with treponemes, these lesions are considered highly infectious. After the mother yaw heals, an atrophic scar with central hypopigmentation and peripheral hyperpigmentation remains.
Secondary stage
Following a period of latency (about 6-16 weeks after the primary stage), disseminated skin lesions, bone lesions, and constitutional symptoms occur. The cutaneous lesions, or the daughter yaws, resemble the mother yaw but are smaller (up to 2 cm in diameter) and are frequently located adjacent to body orifices, particularly the mouth and the nose. The daughter yaws expand, ulcerate, and exude a fibrinous fluid teeming with treponemes, which dries into a crust. The exudate attracts flies, which are bothersome to the person who is affected.
Secondary yaws lesions may occur near primary lesions or elsewhere on the body and may last for weeks to more than 6 months. Macules, papules, nodules, and hyperkeratotic lesions may appear. Climate influences the morphology and the number of lesions. In the dry season, lesions are fewer and macular in appearance. Secondary lesions heal spontaneously and are generally nonscarring and reversible.
Occasionally, central resolution yields circinate or annular scaly lesions resembling fungal infections. These lesions are referred to as tinea yaws. Papulosquamous patches and plaques that resemble syphilis may be noted on any part of the body. Lesions in the axillae or the groin resemble condylomata lata; lesions on the mucous membranes resemble hypertrophic mucous patches.
Papillomas on the plantar surfaces can form thick, hyperkeratotic plaques that may become fissured or eroded. Lesions are painful and cause a deliberate crablike gait (crab yaws).
Skeletal involvement includes painful osteoperiostitis and fusiform soft tissue swelling of the metatarsals and the metacarpals. Some of the early bone changes can be seen on radiographs. Periosteal thickening can often be palpable. [15]
Piannic onychia is a paronychia caused by papillomas in the nail fold.
Patients may develop relapses at intervals up to 5 years after infection. Relapsing lesions tend to occur in the perioral, perianal, and periaxillary areas. The disease then enters a noninfectious latent period, and patients do not exhibit any signs or symptoms. Most patients remain in a noninfectious latent stage for their lifetime.
Tertiary stage
In about 10% of cases, after 5-15 years of latency, a late stage develops, characterized by destructive skin lesions, bone lesions, and, possibly, neurologic and ophthalmologic involvement. Progressively enlarging, painless, subcutaneous nodules develop, which undergo abscess formation, necrosis, and ulceration. Lesions have well-defined edges and an indurated base with granulation tissue and yellowish slough.
Ulcers may become infected, causing destruction of underlying structures. They may also coalesce, forming serpiginous tracts that heal with keloid formation, which leads to crippling deformities and contractures.
Late skeletal lesions consist of hypertrophic periostitis, gummatous periostitis, osteitis, and osteomyelitis. Chronic osteitis of the tibia can lead to saber shins. In about 1% of patients, there is occurrence of bilateral hypertrophic osteitis of the external aspects of the nasal processes of the maxillae with persistent swelling. This condition is referred to as goundou, which slowly progresses over 5-20 years and eventually may lead to massive destruction and perforation of the nose and the palate (gangosa).
Neurologic and ophthalmologic involvement is debated in the literature. Some reports suggest that disc atrophy, optic atrophy, and myeloneuropathies may occur.
Attenuated yaws
Some reports have described an attenuated, less contagious form of yaws in areas of low disease prevalence. A solitary patch or a few dry, flat, gray patches confined to the skin folds have been noted to characterize attenuated yaws. [16, 17]
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Initial papilloma, also called mother yaw or primary frambesioma (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
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Plantar papillomata with hyperkeratotic macular plantar early yaws (ie, crab yaws) (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta.Geneva, Switzerland: World Health Organization; 1984.).
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Osteoperiostitis of the tibia and fibula in early yaws (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
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Early yaws papillomata (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
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Early ulceropapillomatous yaws on the leg (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
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Squamous macular palmar yaws (from Perine PL, Hopkins DR, Niemel PLA, et al. Handbook of Endemic Treponematoses: Yaws, Endemic Syphilis, and Pinta. Geneva, Switzerland: World Health Organization; 1984.).
