[Severe periodontal disease as the cause of a fever of unknown origin].

A 41-year old man was admitted to a university medical centre with a belly ache, bloody diarrhoea and fever with peaks rising up to 39 degrees C. The differential diagnosis included among others infectious bowel disease, tuberculosis and amoeba-infection. After the exclusion of other pathologies the diagnosis morbus Crohn was given. A few days later the patient complained about toothache and severe periodontal disease was diagnosed. Instantly after extraction of the entire dentition the fever disappeared.