Bejel, or endemic syphilis, is a chronic skin and tissue disease caused by infection by the endemicum subspecies of the spirochete Treponema pallidum. Bejel is one of the "endemic treponematoses" (endemic infections caused by spiral-shaped bacteria called treponemes), a group that also includes yaws and pinta. Typically, endemic trepanematoses begin with localized lesions on the skin or mucous membranes. 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, often on the interior of the mouth, followed by the appearance of raised, eroding lesions on the limbs and trunk. Periostitis (inflammation) 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, transmission of bejel is not venereal in nature, generally resulting from mouth-to-mouth contact or sharing of domestic utensils, and the courses of the two diseases are somewhat different. 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. Treatment
It is treatable with penicillin or other antibiotics, resulting in a complete recovery.
It has been found that mothers of patients with this disease have a higher incidence of ICP, suggesting that heterozygote carriers of these mutations are also predisposed to ICP.In addition to genetic changes to bile salt transport molecules, high levels of estrogen glucuronides have been shown to inhibit the bile salt export pump (BSEP) ABCB11, and high levels of progesterone to inhibit the ABCB4 (MDR3) phospholipid transporter.Consequently, both genetic mutations in hepatocyte proteins involved in bile secretion together with inhibition of those proteins by high levels of hormone metabolites in pregnancy may have roles in the pathogenesis of ICP. Environmental factors
A number of features of ICP suggest that environmental factors also have a role in the disease:

It has been reported that the incidence of ICP is higher in winter than summer. The incidence of ICP in Chile has dropped from 14% of pregnancies before 1975 to 4% in 2016. ICP recurs in between 60% and 90% of subsequent pregnancies. Low serum selenium levels have been linked to ICP, although the role of selenium in bile secretion is not known. Diagnosis
ICP is diagnosed by blood tests including a serum bile acid test and liver function test. While most pregnant women experience some itch from time to time, itching without a visible rash, or persistent or extensive itch symptoms should be reported to the midwife or obstetrician.