Bejel, or endemic syphilis, is a chronic skin and tissue disease caused by infection by the ''endemicum'' subspecies of the

spirochete A spirochaete () or spirochete is a member of the phylum Spirochaetota (also called Spirochaetes ), which contains distinctive diderm (double-membrane) Gram-negative bacteria, most of which have long, helically coiled (corkscrew-shaped or ...

Treponema pallidum ''Treponema pallidum'', formerly known as ''Spirochaeta pallida'', is a Microaerophile, microaerophilic, Gram-negative bacteria, gram-negative, spirochaete bacterium with subspecies that cause the diseases syphilis, bejel (also known as endemic ...

''. Bejel is one of the "endemic treponematoses" (

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

infections caused by spiral-shaped bacteria called treponemes), a group that also includes

yaws Yaws is a tropical infection of the skin, bones, and joints caused by the spirochete bacterium ''Treponema pallidum pertenue''. The disease begins with a round, hard swelling of the skin, in diameter. The center may break open and form an ulc ...

and pinta. Typically, endemic trepanematoses begin with localized lesions on the skin or

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

s. Pinta is limited to affecting the skin, whereas bejel and yaws are considered to be invasive because they can also cause disease in bone and other internal tissues.

Signs and symptoms

Bejel usually begins in childhood as a small patch on the

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...

, often on the interior of the mouth, followed by the appearance of raised, eroding lesions on the limbs and trunk. Periostitis (

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

) of the leg bones is commonly seen, and gummas of the nose and soft palate develop in later stages.

Causes

Although the organism that causes bejel, ''Treponema pallidum endemicum'', is morphologically and serologically indistinguishable from ''Treponema pallidum pallidum'', which causes venereal

syphilis Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms depend on the stage it presents: primary, secondary, latent syphilis, latent or tertiary. The prim ...

, transmission of bejel is not venereal. However, recent epidemiological evidence suggests that ''Treponema pallidum endemicum'' may also cause venereal syphilis.

Diagnosis

The diagnosis of bejel is based on the geographic history of the patient as well as laboratory testing of material from the lesions (dark-field microscopy). The responsible spirochaete is readily identifiable on sight in a microscope as a treponema.

Epidemiology

Bejel has been known to be endemic in the

Sahel The Sahel region (; ), or Sahelian acacia savanna, is a Biogeography, biogeographical region in Africa. It is the Ecotone, transition zone between the more humid Sudanian savannas to its south and the drier Sahara to the north. The Sahel has a ...

region spanning from Mauritania and Senegal to Sudan, the other African countries of Côte d'Ivoire, Benin, and Somalia, the

Kalahari Desert The Kalahari Desert is a large semiarid climate, semiarid sandy savanna in Southern Africa covering including much of Botswana as well as parts of Namibia and South Africa. It is not to be confused with the Angolan, Namibian, and South African ...

spanning from Namibia to Zimbabwe,

West Asia West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...

spanning from Syria to Pakistan, and the

Arabian Peninsula The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

countries of Kuwait, Saudi Arabia, the United Arab Emirates, and Oman. It is unclear if it remains endemic in these countries, but a recent study suggested that the causative bacteria circulates outside of this range as venereal syphilis.

References

External links