Syphilis skin lesions in a young baby who has had the disease since birth. This is called congenital syphilis and the baby is infected during pregnancy by the mother. Syphilis is caused by the bacterium Treponema pallidum. Congenital syphilis is rare in the developed world, due to pregnant women being routinely screened for the disease. Skin lesions are a symptom of an early stage of syphilis. For all stages, the treatment is with the antibiotic drug penicillin. Photographed in Africa.