Glossitis can cause glossitis, which tends to be painful, smooth and shiny. Bacterial, viral or fungal infections can cause glossitis. "Candida" species are involved in median rhomboid glossitis. Syphilis is now relatively rare, but the tertiary stage can cause diffuse glossitis and atrophy of lingual papillae, termed "syphilitic glossitis", "luetic glossitis" or "atrophic glossitis of tertiary syphilis". It is caused by Treponema pallidum and is a sexually transmitted infection. Many conditions can cause glossitis via malnutrition or malabsorption, which creates the nutritional deficiencies described above, although other mechanisms may be involved in some of those conditions listed. A painful tongue may
Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms