[Anorectal manifestations in systemic diseases].

Numerous systemic diseases (vasculitis, connective tissue disease or sarcoidosis) can display an involvement of the perianal skin, the rectum and/or the anus. Such knowledge is important in order to treat these complications specifically when possible. Lesions of the anorectum arising from systemic diseases can sometimes cause perforations in the peritoneal cavity (if concerning the higher portion of the rectum) and/or fistulization to the anal margin. Differential diagnosis, mostly infectious or inflammatory (Crohn's disease) must be ruled out in every case. Other systemic diseases can display specific manifestations as this is the case in scleroderma which can lead to anal incontinence. Despite the relative rarity of these manifestations, their ignorance would forbid global management of these complex diseases. It should thus be detected in each consultation and a regular follow-up must be provided with a proctologist and/or a gastroenterologist when needed.