yaws (redirected from Thymosis)

Yaws 

Definition

Yaws is a chronic illness which first affects the skin, and then affects the bones.

Description

Yaws tends to strike children, particularly between the ages of two and five. It is common in areas where poverty and overcrowding interfere with good hygiene practices. The most common locations are in rural areas throughout Africa, Southeast Asia, and in locations bordering the equator in the Americas.

Causes and symptoms

Yaws is caused by a spiral-shaped bacterium (spirochete) called Treponema pertenue. This bacterium belongs to the same family as the bacterium that causes syphilis.

Yaws is passed among people by direct skin contact. It requires some kind of a scratched or insect bitten area in order for the bacteria to actually settle in and cause infection. An injured spot on the leg is the most common part of the body through which the bacteria enter. Young children, who are constantly bumping themselves in play, who wear little clothing, who do not wash their hands often, and who may frequently put their hands in their mouths, are particularly susceptible.

The first symptom of yaws occurs three to four weeks after acquiring the bacteria. The area where the bacteria originally entered the skin becomes a noticeable bump (papule). The papule grows larger and develops a punched-out center (ulcer), covered with a yellow crust. Lymph nodes in the area may become swollen and tender. This first papule may take as long as six months to heal. Secondary soft, gummy growths then appear on the face, arms and legs, and buttocks. These soft, tumor-like masses may grow on the soles of the feet, causing the patient to walk in an odd and characteristic fashion on the sides of his or her feet (nicknamed "crab yaws"). More destructive tumors may then disrupt the bones of the face, the jaw, and the lower leg. Ulcers around the nose and on the face may be very mutilating.

Diagnosis

Samples taken from the first papules may be examined using a technique called dark-field microscopy. This often allows the spirochetes to be identified. They may also be identified in fluid withdrawn from swollen lymph nodes. Various tests can also be run on blood samples to determine if an individual is producing antibodies (special immune cells) which are specifically made in response to the presence of these spirochetes.

Treatment

A single penicillin injection in a muscle is sufficient to completely end the disease.

Prognosis

Without treatment, yaws is a terribly disfiguring chronic illness. With appropriate treatment, the progression of the disease can be completely halted.

Prevention

For a time, the World Health Organization (WHO) was working to totally eradicate yaws, just as smallpox was successfully eradicated. This has not occurred, however. WHO continues to work to identify and respond to outbreaks quickly, in an effort to at least slow the spread of yaws.

Resources

Organizations

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

Key terms

Papule — A raised bump on the skin.

Ulcer — A punched-out, irritated pit on the skin.

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yaws (yawz) an endemic infectious tropical disease caused by Treponema pertenue, usually affecting persons under 15 years of age, spread by direct contact with skin lesions or by contaminated fomites. It is initially manifested by the appearance of a papilloma at the site of inoculation; this heals, leaving a scar, and is followed by crops of generalized granulomatous lesions that may relapse repeatedly. There may be bone and joint involvement.

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yaws (yôz)

n.

An infectious tropical disease caused by Treponema pertenue, characterized by the development of crusted granulomatous ulcers on the extremities that may cause bone and joint destruction in later stages of the disease. Also called boubas, bubas, frambesia, granuloma tropicum, pian, rupia.

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yaws

[yôs]

Etymology: Afr, yaw, raspberry,

a chronic nonvenereal infection caused by the spirochete Treponema pallidum subspecies pertenue, transmitted by direct contact. Yaws has been classified into four stages.

1 primary: the initial lesion is observed.

2 secondary stage: multiple lesions due to desemination of spirochetes.

3 latent stage: this stage is asymptomatic; however, relapse of lesions may occur.

4 tertiary stage: bone joint and soft tissue deformities may occur at this stage, and lesions are not contagious at this point. It is characterized by chronic, ulcerating sores anywhere on the body but usually on the legs, with eventual tissue and bone destruction, leading to crippling if untreated. The sores are yellowish or reddish tumors that in shape and appearance often resemble currants, strawberries, or raspberries. It is a disease of unsanitary living conditions and may be effectively treated with penicillin G. All serologic tests for syphilis may be positive in yaws. The infection may afford protection against syphilis. Also called bouba, buba, frambesia, framboesia, parangi, patek, pian. Compare bejel, pinta, syphilis.

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Y chromosome,

n a sex chromosome that in humans and many other species is present only in the male, appearing singly in the normal male. It is carried as a sex determinant by one half of the male gametes. None of the female gametes contain a Y chromosome.

yawn,

n an involuntary act of opening the oral cavity wide and taking a deep breath. It tends to occur when a person is bored, drowsy, or depressed and may be accompanied by upper body movements to aid chest expansion.

yaws

n a disease caused by
T. pertenue. It occurs in hot regions; raspberry-like excrescences occur on the hands, face, feet, and external genitalia.